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Modelling Greenhouse Gas Emissions from Scottish Housing: Final Report








Barker, T et al (2007) "Technical Summary" in Metz, B et al (eds) Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge: Cambridge University Press.


The series of authoritative IPCC reports - contributions to the Fourth (and latest) Assessment - provide an essential framework for all regional, national and sectoral studies linked to the assessment of options for mitigating climate change. Residential and commercial buildings are identified as a key sector. The reports collectively establish baselines for assessments of future emissions and mitigation potential (around 30%) from the building sector. The Technical Summary has four parts. Part A sets out the frameworks to describe mitigation of climate change in the context of other policies and decision-making. Part B assesses long-term stabilization targets, how to get there and what the associated costs are. Part C focuses on the detailed description of the various sectors responsible for greenhouse gas ( GHG) emissions, the short- to medium-term mitigation options and costs in these sectors, the policies for achieving mitigation, the barriers to getting there and the relationship with adaptation and other policies that affect GHG emissions. Part D assesses cross-sectoral issues. This Technical Summary has an additional chapter which deals with gaps in knowledge. The Technical Study contains tabulated information on the impact and effectiveness of selected policy instruments aimed at mitigating GHG emissions in the buildings sector using best practices. Co-benefits and links to sustainable development are identified. The limited overall impact of policies so far is argued to be due to several factors: 1) slow implementation processes; 2) the lack of regular updating of building codes; 3) inadequate funding; 4) insufficient enforcement.

Provides the authoritative framework for international and national policy responses linked to meeting the challenge of climate change through the assessment and implementation of mitigation and adaptation options. Presents data on emission trends and future projections. Presents data on energy consumption and supply trends and projections. Sets out the baseline scenarios which inform these projections. Defines framing issues with particular analysis of the potential for and the costs and benefits of mitigation approaches.

Identifies residential buildings as a key policy sector. Describes the status of the sector and emission trends. Categorises measures to reduce GHG emissions in the sector and predicts the mitigation potential. Identifies measures with largest potential and measures providing cheapest mitigation options. Summarizes the key policy tools shown to be successful in cutting GHG emissions from buildings (Table TS8). Identifies co-benefits. Identifies gaps in knowledge.

Mitigation potential as % of national baseline for buildings: Technical: 21%-54% Economic: 12%-25% Market: 15%-37%.

CEC (2007) Limiting Global Climate Change to 2 degrees Celsius: The Way Ahead for 2020 and beyond, COM(2007) 2 final, Brussels: Commission of the European Communities.


This Communication represents a key part of the official EU response to accumulation of scientific evidence on climate change and its impacts, as set out in key studies such as the IPCC Fourth Assessment and the Stern Review. It argues that urgent action is required to limit climate change a manageable level. The EU must adopt the necessary domestic measures and take the lead internationally to ensure that global average temperature increases do not exceed pre-industrial levels by more than 2°C. This Communication and the accompanying impact assessment show that this is technically feasible and economically affordable if major emitters act swiftly. It argues that the benefits far outweigh the economic costs. In deciding the next steps in climate change policy the European Council should take decisions, which will enhance the conditions for reaching a new global agreement to follow on from the Kyoto Protocol's first commitments after 2012. EU should take on a firm independent commitment to achieve at least a 20 % reduction of GHG emissions by 2020. This can be achieved without affecting their economic growth and poverty reduction, by taking advantage of the wide range of energy and transport related measures that not only have a major emissions reduction potential, but also bring immediate economic and social benefits in their own right. By 2050 global emissions must be reduced by up to 50 % compared to 1990, implying reductions in developed countries of 60-80 % by 2050. Energy use of buildings can be reduced by up to 30 % by expanding the scope of the Directive on energy performance of buildings and introducing EU performance requirements promoting very low energy buildings (leading to their widespread use by 2015).

Establishes in an authoritative way the case for mitigation of and adaptation to climate change, with clear implications and targets for international or national carbon management policies in the built environment field generally and the domestic sector in particular

Frames and defines the policy agenda as a response to the climate change challenge, providing a source of reference on the scale of the challenge together with proposed actions, costs and benefits.

Concludes that energy use of buildings can be reduced by up to 30 % by expanding the scope of the Directive on energy performance of buildings and introducing EU performance requirements promoting very low energy buildings (leading to widespread use by 2015). As climate change will affect the less advantaged parts of society, governments should envisage special energy policies for social housing.

Projects the need for an international agreement on energy efficiency standards engaging key appliance-producing countries. This will benefit market access and help reduce GHG emissions.

Sets the EU objective of a 30 % reduction in greenhouse gas emissions ( GHG) by developed countries by 2020 (compared to 1990 levels).

CEC (2007) Towards a European Strategic Energy Technology Plan, COM(2006) 847 final Brussels: Commission of the European Communities


This communication provides a guiding vision of a European Union with a thriving and sustainable economy, with world leadership in a diverse portfolio of clean, efficient and low-carbon energy technologies as a motor for prosperity and a key contributor to growth and jobs. Energy technology has a vital role to play in breaking once and for all the link between economic development and environmental degradation. The current trends and their projections into the future demonstrate that we are simply not doing enough to respond to the energy challenge. In combination with national activities, working at European level with an adequate combination of innovation and regulatory measures has produced substantial results. However, the continuation of 'business as usual' is no longer an option.. The European Union must act jointly and urgently, agreeing and implementing a European Strategic Energy Technology Plan ( SET-Plan). The International Energy Agency estimates that 16 trillion Euros will have to be invested in energy-supply infrastructure worldwide in the period up to 2030

Presents an independent overview of the energy technologies that can contribute to achieving EU goals on reducing climate emissions and securing future energy supplies. Identifies planning/building regulations amongst a set of critical "demand-pull" instruments


CEC (2006), Action Plan for Energy Efficiency: Realising the Potential. COM (2006)545 final, Brussels: Commission of the European Communities


This Action Plan outlines a framework of policies and measures with a view to intensify the process of realising the over 20% estimated savings potential in EU annual primary energy consumption by 2020. The Plan lists a range of cost-effective measures, proposing priority actions to be initiated immediately, and others to be initiated gradually over the Plan's six-year period. Further action will be required to reach the full potential by 2020. The Action Plan is intended to mobilise the general public and policy-makers at all levels of government, together with market actors, and to transform the internal energy market in a way that provides EU citizens with the globally most energy-efficient infrastructure, buildings, appliances, processes, transport means and energy systems. Given the importance of the human factor in reducing energy consumption, this action plan also encourages citizens to use energy in the most rational manner possible.

Identifies energy efficiency in the building sector as a top priority.

A comprehensive framework of directives and regulations to improve energy efficiency in energy-using products, buildings and services is in force in Community law. These include the Eco-Design Directive, the Energy Star Regulation, the Labelling Directive and its 8 implementing Directives, the Directive on Energy End-Use Efficiency and Energy Services and the Energy Performance of Buildings Directive.

The Commission will begin, in 2007, the process of adopting minimum energy performance standards (eco-design requirements) in the form of implementing Directives for 14 priority product groups including boilers, water heaters, consumer electronics, copying machines, televisions, standby modes, chargers, lighting, electric motors and other products. Products that do not meet the agreed minimum requirements may not be put on the market. The Plan proposes, as a priority, action to expand the scope of the Energy Performance of Buildings Directive substantially in 2009, after its complete implementation. It will also propose EU minimum performance requirements for new and renovated buildings (kWh/m_).

Identifies the largest cost-effective savings potential with the residential (households) buildings sector where the full potential is now estimated to be around 27% of energy use. In residential buildings, retrofitted wall and roof insulation offer the greatest opportunities.

Eurima (2006) Better buildings through energy efficiency: a roadmap for Europe, Brussels: European Insulation Manufacturers Association.


This report presents the results of a scan of best practices in building energy efficiency policies and programmes, and recommends suitable instruments to endorse building energy efficiency in Europe. Best practices are classified according to the sector they are targeting (residential, commercial and/or public, and new and/or existing buildings), for each of the four main types of instruments that are generally differentiated in policy analysis.

European Union (2008). Boosting Growth and Jobs by Meeting our Climate Change Commitments, Brussels: European Union.


The European Commission has agreed a far-reaching package of proposals that will deliver the European Council's commitments to fight climate change and promote renewable energy. The package seeks to deliver reductions in greenhouse gases by at least 20% in the European Union and increase to 20% the share of renewable energies in the energy consumption by 2020, as agreed by EU leaders in March 2007. The emissions reduction will be increased to 30% by 2020 when a new global climate change agreement is reached. The proposals demonstrate that the targets agreed last year are technologically and economically possible and provide a unique business opportunity for thousands of European companies. These measures will dramatically increase the use of renewable energy in each country and set legally enforceable targets for governments to achieve them. All major CO 2 emitters will be given an incentive to develop clean production technologies through a thorough reform of the Emissions Trading System ( ETS) that will impose an EU-wide cap on emissions.

Reinforces the broader socio-economic case for international and national investment in carbon emission reduction measures.

Gupta, S et al (2007) "Policies, Instruments and Co-operative Arrangements" in Metz, B et al (eds ), Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge: Cambridge University Press.



This chapter of the IPCC Fourth Assessment Report on Mitigation synthesizes information from the relevant literature on policies, instruments and co-operative arrangements, focusing mainly on new information that has emerged since the Third Assessment Report ( TAR). It reviews national policies, international agreements and initiatives of sub-national governments, corporations and non-governmental organizations ( NGOs). Understanding how to accelerate policy adoption may be the most important research topic for the immediate future. Since the IPCC was formed nearly 20 years ago atmospheric GHG concentrations have gone up from 354 to 385 ppm (or approximately 25% of the total increase since the pre-industrial level of 270 ppm) as the emissions of GHG have risen. The report addresses the questions:

  • Why has the application of policies been so modest?
  • Why is the global community not on a faster implementation track?
  • Why have - at the very least - hedging strategies not emerged in many more countries?
  • Is the scale of the problem too large for current institutions?
  • Is there a lack of information on potential impacts or on low-cost options?
  • Has policy-making been influenced by the special interests of a few?

Provides reference to information for assessing how well different policy instruments meet the criteria of environmental effectiveness, cost-effectiveness, distributional effectiveness (equity) and institutional feasibility.

IPCC (2007) "Summary for Policymakers" in Metz, B et al (eds) Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment. Report of the Intergovernmental Panel on Climate Change, Cambridge: Cambridge University Press.



This Working Group III contribution to the IPCC Fourth Assessment Report (AR4) focuses on new literature on the scientific, technological, environmental, economic and social aspects of mitigation of climate change, published since the IPCC Third Assessment Report ( TAR) and the Special Reports on CO 2 Capture and Storage ( SRCCS) and on Safeguarding the Ozone Layer and the Global Climate System ( SROC).

The summary is organised into six sections:

  • Greenhouse gas ( GHG) emission trends
  • Mitigation in the short and medium term, across different economic sectors (until 2030)
  • Mitigation in the long-term (beyond 2030)
  • Policies, measures and instruments to mitigate climate change
  • Sustainable development and climate change mitigation
  • Gaps in knowledge.

The summary argues in particular that energy efficiency options for new and existing buildings could considerably reduce CO 2 emissions with net economic benefit. Many barriers exist against tapping this potential, but there are also large co-benefits.

Presents the authoritative case for mitigation of and adaptation to climate change, with clear implications and targets for international or national carbon management policies in the built environment field generally and the domestic sector in particular.

By 2030, about 30% of the projected GHG emissions in the building sector can be avoided, with net economic benefit

IPCC (2007): Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Metz, B et al (eds), Cambridge: Cambridge University Press.


"Climate Change 2007 - Mitigation", the third volume of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change ( IPCC), provides an in-depth analysis of the costs and benefits of different approaches to mitigating and avoiding climate change.

The volume aims to answer essentially five questions relevant to policymakers worldwide:

  • What can we do to reduce or avoid climate change?
  • What are the costs of these actions and how do they relate to the costs of inaction?
  • How much time is available to realise the drastic reductions needed to stabilise greenhouse gas concentrations in the atmosphere?
  • What are the policy actions that can overcome the barriers to implementation?
  • How can climate mitigation policy be aligned with sustainable development policies?

Frames and define the policy agenda in the domestic carbon emissions sector in response to the climate change challenge, providing a source of reference on the scale of the challenge together with likely actions, costs and benefits. The concept of "mitigation potential" has been developed to assess the scale of GHG reductions that could be made, relative to emission baselines, for a given level of carbon price (expressed in cost per unit of carbon dioxide equivalent emissions avoided or reduced). Mitigation potential is further differentiated in terms of "market potential" and "economic potential". Ideally, an effective (from a policy perspective) domestic carbon reductions model would flag if not fully quantify the co-benefits (such as health and reduced pressure on ecosystems) associated with energy saving measures and provide some indication of the enhance cost savings this would bring

Levine, M et al (2007) "Residential and commercial buildings" in Metz, B et al (eds) Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge: Cambridge University Press.


The key conclusion of this chapter of the main report on climate change mitigation is that substantial reductions in CO 2 emissions from energy use in buildings can be achieved over the coming years using mature technologies for energy efficiency that already exist widely and that have been successfully. A significant portion of these savings can be achieved in ways that reduce life-cycle costs, thus providing reductions in CO 2 emissions that have a net benefit rather than cost. However, due to the long lifetime of buildings and their equipment, as well as the strong and numerous market barriers prevailing in this sector, many buildings do not apply these basic technologies to the level life-cycle cost minimisation would warrant). A survey of the literature (80 studies) indicates that there is a global potential to reduce approximately 29% of the projected baseline emissions by 2020 cost-effectively in the residential and commercial sectors, the highest among all sectors studied. Over the whole building stock the largest portion of carbon savings by 2030 is in retrofitting existing buildings and replacing energy using equipment due to the slow turnover of the stock. There are, however, substantial market barriers that need to be overcome and a faster pace of well-enforced policies and programmes pursued for energy efficiency and de-carbonisation to achieve the indicated high negative and low-cost mitigation potential.

Presents a definitive analysis of:

  • Trends in buildings sector emissions,
  • Scenarios of carbon emissions resulting from energy use on buildings, GHG
  • Mitigation options in buildings and equipment,
  • Potential for and costs of greenhouse gas mitigation in buildings
  • Co-benefits of GHG mitigation in the residential sector
  • Barriers to adopting building technologies and practices that reduce GHG emissions
  • Policies to promote GHG mitigation in buildings.

Economic co-benefits include the creation of jobs and business opportunities, increased economic competitiveness and energy security. Other co-benefits include social welfare benefits for low-income households, increased access to energy services, improved indoor and outdoor air quality, as well as increased comfort, health and quality of life. Design strategies for energy-efficient buildings include reducing loads, selecting systems that make the most effective use of ambient energy sources and heat sinks and using efficient equipment and effective control strategies. An integrated design approach is required to ensure that the architectural elements and the engineering systems work effectively together.

Confirms that energy use by household appliances, office equipment and consumer electronics is an important fraction of total electricity use in households.

Improvements in the thermal envelope can reduce heating requirements by a factor of two to four compared to standard practice.

Operable (openable) windows are available with heat flows that have only 25-35% of the heat loss of standard non-coated double-glazed (15 to 20% of single glazed) windows.

In residential construction, installation in walls of a continuous impermeable barrier, combined with other measures such as weatherstripping, can reduce rates of air leakage by a factor of five to ten compared to standard practice in northern Europe.

Aggressive envelope measures combined with optimisation of passive solar heating opportunities, as exemplified by the European Passive House Standard, have achieved reductions in purchased heating energy by factors of five to thirty.

By combining a high-performance thermal envelope with efficient systems and devices, 50-75% of the heating and cooling energy needs of buildings as constructed under normal practice can either be eliminated or satisfied through passive solar design.

Lighting energy use can be reduced by 75-90% compared to conventional practice through (i) daylighting with occupancy and daylight sensors to dim and switch off electric lighting; (ii) the most efficient lighting devices available; and (iii) such measures as ambient/task lighting.

In existing buildings, Bell and Lowe (2000) believe that a reduction in energy use of 50% could be achieved at modest cost using well-proven (early 1980s) technologies, with a further 30-40% cut through other measures.

For typical standards of building construction, the embodied energy is equivalent to only a few years of operating energy.






Barker, K (2004). Review of Housing Supply: Delivering Stability: Securing our Future Housing Needs. Report to HM Treasury.


(Full Report)

(Executive Summary)

This Review sets out a series of policy recommendations to address the lack of supply and responsiveness of housing in the UK. The recommendations cover a broad spectrum of issues. It suggests that we need to integrate economic considerations into the planning system, that we need a better means of assessing the costs and benefits of development and land use and that we need to acknowledge market signals and use the information provided. These recommendations will also require concerted action on the part of the house building industry. In the past, quality of service to consumers and considerations of sustainability, design and innovation have been secondary to the desire to secure land. The signs are that the industry recognises these failings, which arise in part from the volatility of the housing market, and the report identifies a determination to do better.

Sets out three scenarios as the basis for UK housing policy up to and beyond 2020.

Reducing the trend in real house prices to 1.8 percent would require an additional 70,000 private sector homes per annum; and more ambitiously, to reduce the trend in real house prices to 1.1 per cent, an additional 120,000 private sector homes per annum would be required.

An increase in supply of social housing of 17,000 homes each year is believed to be required to meet the needs among the flow of new households. There is also a case for provision at up to 9,000 a year above this rate in order to make inroads into the backlog of need

DCLG (2007) Planning and Climate Change. Supplement to Planning Policy Statement 1. London: DCLG


Planning Policy Statements ( PPS) set out the Government's national policies on different aspects of spatial planning in England. PPS1 sets out the overarching planning policies on the delivery of sustainable development through the planning system. This PPS on climate change supplements PPS1 by setting out how planning should contribute to reducing emissions and stabilising climate change and take into account the unavoidable consequences. A companion guide provides practice guidance and support for the implementation of the policies in this PPS.

The planning system needs to support the delivery of the timetable for reducing carbon emissions from domestic and non-domestic buildings. A progressive tightening of Building Regulations is to require major reductions in carbon emissions from new homes to get to zero carbon by 2016. This PPS sets out how regional and local planning can best support achievement of the zero-carbon targets. DEMScot needs to acknowledge the role of planning.

DEFRA (2007) UK Energy Efficiency Action Plan London: DEFRA.


This Action Plan sets out the package of policies and measures the UK Government have put in place to deliver improvements in energy efficiency in the UK in order to contribute to the achievement of their climate and energy policy objectives and to meet the 9% energy saving target by 2016 under the European Union's Energy End-Use Efficiency and Energy Services Directive. The Plan notes that carbon emissions from buildings account for 45% of total emissions, with housing making up 27%.

Provides guidance on government measures to be taken within the household sector to contribute to the achievement of climate and energy policy objectives and to meet the 9% energy saving target by 2016 under the European Union's Energy End-Use Efficiency and Energy Services Directive. The energy saving target in the Energy End-Use Efficiency and Energy Services Directive applies to the UK as a whole

Around 30% of the houses that will be standing in 2050 are yet to be built, representing about nine million new homes across the UK.

Table 3 (page 14) sets out the expected annual energy savings (and equivalent carbon reductions) in the household sector for 2010, 2016 and 2020 from implementation of a range of energy efficiency programmes and other measures.

Friends of the Earth (2006) Delivering Sustainable Housing - MPs Briefing. London: Friends of the Earth .


This briefing argues that the government has a major opportunity to secure a step change in the environmental performance of housing by reducing greenhouse gas emissions and delivering low carbon and sustainable communities. This will be essential for economic as well as environmental reasons. Climate change will cause more severe climate disasters and much greater damage to communities and economies. It will also be the poorest who will be hit hardest - they are least able to protect their property and are less likely to be insured. Climate change will also affect the economy in other ways - for example increased spending needed to build flood defences and protect coastlines: all diverting spending away from other priorities. Action on housing is urgently needed to prevent economic damage from climate change. Although better designed housing can cost more, this is a small percentage of total costs and as more green homes get built, the unit cost will fall. Better designed and more efficient homes have greatly reduced running costs - a major benefit particularly for lower income households who spend a greater percentage of their income on electricity, heating and water..

Current plans suggest that creating the materials and constructing 2.8 million new homes by 2016 will release 142.9 million tonnes of carbon dioxide. In addition, over a 15 year period an additional 50 million tonnes of carbon dioxide will be released due to energy use in the home. This equates to around 12 million tonnes of carbon dioxide emissions each year, which is equivalent to ten per cent of current transport emissions. If higher house building scenarios are followed then emissions would increase by a further 60 million tonnes more over a 15 year period

Gibbons D, Singler R (2008) Cold Comfort: A review of coping strategies employed by households in fuel poverty. London: Inclusion/Energy Watch.


A literature review on research into fuel poverty. Identified three responses to fuel poverty:

  • reducing fuel use by self-rationing or disconnection
  • reducing spending on other things e.g. food
  • getting into debt (especially young households or those with children)

Better energy efficiency can lead to three outcomes:

  • lower fuel use and/or
  • lower expenditure, and/or
  • a warmer home.

ODPM (2005) A Sustainability Impact Study of Additional Housing Scenarios in England. London: Office of the Deputy Prime Minister.

http://www.communities. gov.

This study assesses the potential sustainability impacts associated with different scenarios of development. It was driven by the need to consider the implications of a step change in housing supply as recommended by the Barker Review, with the intention of lowering the trend in real house price increases. Nine scenarios were assessed in addition to the baseline planned growth, representing three levels of additional construction between 2006 and 2015 (25,000, 50,000 and 100,000 extra dwellings per annum) and three regional distributions (all additional development in the four southern regions, all additional development in the south and midlands, and additional development across all regions of England). The study has assessed the following pressures:

  • Requirement for land.
  • Demand for construction materials.
  • Generation of construction and household waste.
  • Demand for energy use including embodied energy;
  • Demand for water.
  • Demand for transport.
  • Implications for regional and local economies; and
  • Implications for communities.

May provide a useful source of reference for different growth scenarios for housing together with projected implications for carbon dioxide emissions (see for example Table 3).

Specifying EcoHomes 'excellent' as the standard requirement for homes could lead to a reduction in CO 2 emissions per property and an overall reduction of between 1.1 Mt/year (17.1%) and 1.53 Mt/year (17.4%) of CO 2e at 2016 when compared to houses at current Building Regulations standards.

Royal Commission on Environmental Pollution (2007). Twenty-Sixth Report. The Urban Environment. London: Royal Commission on Environmental Pollution.


The UK government has the goal of cutting the UK's carbon dioxide ( CO 2) emissions by 20% by 2010 and 60% by 2050. However, recent forecasts suggest that net CO 2 emissions will decline by only 9% in the 30-year period 1990-2020. This means that CO 2 emissions would need to fall five times faster over the following 30-year period (2021-2050) to achieve the remaining 51% reduction. Questions must be asked about how these long-term cuts will be achieved. Moreover, the recent Stern Review of the economics of climate change warns of the increased expense associated with delaying emission reductions. Much of the UK's climate mitigation policy is concerned with specific sectors and technologies, with less focus on the geographic distribution of emissions. However, information has recently been published on CO 2 emissions from UK local authorities and regions. This vividly illustrates the pattern of cumulative association with large urban areas, and the importance of considering the local urban situation and the role local authorities could play in the strategy to cut emissions and reduce environmental impacts generally. The planning system deals with land use and development and mainly affects new development. Some environmental principles have been embedded in the planning system, but there are other areas where action is needed to reduce and manage environmental impacts. The study concludes that much of the necessary technology to improve the environmental impact of urban areas already exists. The challenge for policy is to increase greatly its rate of installation and to encourage the essential changes in behaviour that will ensure that such technologies will deliver on their environmental potential.

Provides an authoritative critique of current government actions to reduce carbon emissions in the housing sector.

Reinforces the need for a better understanding continue to need a better understanding of ways in which people actually behave if progress is to be made in terms of energy use.

Stern, N (2006) Stern Review on the Economics of Climate Change London: UKHM Treasury.


The Stern Review assesses a wide range of evidence on the impacts of climate change and on the economic costs, and has used a number of different techniques to assess costs and risks. From all of these perspectives, the evidence gathered by the Review leads to a simple conclusion: the benefits of strong and early action far outweigh the economic costs of not acting. Using the results from formal economic models, the Review estimates that if we don't act, the overall costs and risks of climate change will be equivalent to losing at least 5% of global GDP each year, now and forever. If a wider range of risks and impacts is taken into account, the estimates of damage could rise to 20% of GDP or more. In contrast, the costs of action - reducing greenhouse gas emissions to avoid the worst impacts of climate change - can be limited to around 1% of global GDP each year. The second half of the Review considers the complex policy challenges involved in managing the transition to a low-carbon economy and in ensuring that societies can adapt to the consequences of climate change that can no longer be avoided

Provides the largest, most up-to-date, and in UK policy terms the most significant study of the economics of climate change. Presents the most thorough and rigorous available analysis of the costs and risks of climate change, and the costs and risks of reducing emissions

An annex outlines sources of emissions from the buildings sector now, historical and projected business as usual trends in emissions, drivers behind emissions growth, and prospects for cutting emissions from this sector.

Buildings currently account for 8% of greenhouse gas emissions, or 20% if upstream emissions associated with electricity and heat are included. Greenhouse gas ( GHG) emissions from buildings arise from:-

1. Direct combustion of fossil fuels in residential and commercial buildings, amounting to 3.3 Gt CO 2. Almost half of these emissions were from combustion of oil, around 40% from gas, and the remainder from coal.

2. Upstream (indirect) CO 2 emissions from the power sector via demand for electricity and district heat. Buildings consume about half of the electricity and heat produced by the power sector. In this way buildings were indirectly accountable for about 5.4 GtCO2 in 2003

World Wildlife Fund (with IPPR and RSPB) (2007). 80% Challenge: Delivering a Low Carbon UK Godalming: WWF.


In this work, the Institute of Public Policy Research, WWF and the Royal Society for the Protection of Birds ( RSPB) set out to investigate whether a target of 80% can be achieved in the UK by domestic efforts alone and what the costs of doing so would be. The report concludes that the costs of attaining an 80% target would be roughly 2 and 3 times those of attaining a 60% target without aviation emissions, but these costs would still be, at most, half the costs of adapting to climate change and perhaps nearer one tenth. Costs could be further reduced by implementing aggressive policies to improve energy efficiency.

DEMScot economic modelling may find interest in reference to the two approaches used in this study - the MARKAL- MACRO model, used by the government for the 2007 Energy White Paper, and a model developed by Professor Dennis Anderson at Imperial College, employed for the Stern Review on the economics of climate change

Contains assumptions on the marginal costs of carbon - see page 22






AEA Technology (2006) Scottish Energy Study Volume 1 Energy in Scotland: Supply and Demand. Study for the Scottish Executive. Edinburgh: Scottish Executive


This report describes Scotland's current energy supply, energy consumption and energy-related CO 2 emissions during 2002, and provides background information on how this picture was developed. In 2002, Scotland's energy was fuelled directly by gas and oil and also using electricity, generated predominantly from nuclear fuel and coal, with a lesser contribution from gas. The main demand was in the domestic sector, as energy was for space and water heating in homes, then for transport, especially road transport: these two sectors use over 60% of Scotland's delivered energy. The purpose of the study is to inform Scottish Executive decision-making in areas such as improving energy efficiency, the development of renewable energy, the Scottish Climate Change Programme and sustainable development. The aim is to supply the Scottish Executive with an understanding of current energy supply and demand, together with the factors driving these. This will be used to develop an appreciation of the opportunities open to Scotland and the barriers to sustainable energy use that must be addressed. The study focuses on initiatives that will succeed at the Scottish level, and so can capitalise on, and develop, Scotland's natural resources, its industrial capability and the skills of its workforce.

Presents data describing Scottish energy supply and demand, together with associated CO 2 emissions. Information is also given on how the data were derived.

Provides conventions for estimating carbon emissions. Average emission factor for Scotland quoted as 0.406 kgCO2/kWh

Fig 2: Scottish domestic sector energy split. DTI statistics adjusted to take account of Scottish factors. Discussed in Appendix 1.

Fig 3: Comparison of Scotland and UK domestic fuel split.

Fig 23: Final energy by sector, in Scotland. Domestic: Solid (3.02 TWh) Oil (5.82) Gas (34.48) Electricity (12.27) Renewables (0.46) Total (56.05)

Fig 28: Scottish Emission Maps of Total Carbon Dioxide Emissions in 2003 and equivalent map for carbon dioxide associated with energy use

Fig 29: Provides a comparison of Scottish versus UK per capita energy consumption by sector (Fig S10)

AEA Technology (2006) Scottish Energy Study Summary Report. Study for the Scottish Executive. Edinburgh: Scottish Executive.


Overall in 2002, Scotland consumed approximately 175 TWh of energy, covering a wide range of different energy uses. This overall energy figure was distributed amongst a range of different consumers. Scotland's energy can be categorised into a set of four distinct sectors which account for the majority of energy use:

  • Domestic - individuals and families in their homes.
  • Transport - those using public and private transport.
  • Industry - individuals and companies involved in various industrial processes.
  • Services - those involved in other business activities such as tourism and financial services.

In 2002, Scotland emitted 44 million tonnes of CO 2 resulting from the production and consumption of energy. This is around 9% of the equivalent UK emissions, which is proportionate to the 8.5% of the UK population that live in Scotland. The domestic sector is the largest consumer of energy. Energy demand for domestic uses in Scotland is greater than the UK average, mainly because of the harsher climate. It also reflects the differences in the condition of Scotland's building stock. For example, evidence suggests that the fraction of Scottish homes without loft insulation is more than twice that in England. Balancing this is the fact that around 30% of dwellings in Scotland are flats (requiring less energy for heating) compared to only 20% in England.

AEA Technology (2006) Scottish Energy Study Volume 2 A Changing Picture: Comparison of 2002 Energy Study findings with an earlier study using 1990 data Study for the Scottish Executive. Edinburgh: Scottish.


This report compares the results of the Energy Study from 2002 (presented in Volume 1) with data for energy supply and demand in Scotland in 1990. The main source of these data is a study produced by AHS Emstar, which was published in 1993 and presents an analysis of data for 1989/90.

Addresses how the Scottish energy picture has changed in recent years: the results derived in Volume 1 are compared with the findings of an earlier study based on 1990 data.

Domestic consumption rose by 15% over the 12 years from 48.5 to 56.0 TWh. Total CO 2 emissions fell from 46.5 to 44.0 Mt ( i.e. 5.4%), mainly as a result of changes to the fuel mix.

AEA Technology (2008) Scottish Energy Study Volume 3 Energy Demand Database Study for the Scottish Executive. Edinburgh: Scottish Executive

A brief guide to an energy database: summarising Scottish energy use by sector.

AEA Technology (2008 ) Scottish Energy Study Volume 4 Issues, Opportunities and Barriers Study for the Scottish Executive. Edinburgh: Scottish Executive

Considers the many factors that influence energy use in Scotland today. This volume considers key drivers. Based on this understanding it identifies the opportunities to improve energy use within Scotland and the barriers which must be overcome if this is to be achieved.

AEA Technology (2008) Scottish Energy Study Volume 5 Looking Forward Study for the Scottish Executive. Edinburgh: Scottish Executive

Considers how Scotland's energy use could change in the medium term to 2020, using projections of demand and supply informed by different scenarios that will influence energy use in the future.

Energy Saving Trust (2007 ) EU Energy Performance of Buildings Directive. Implementation in Scotland. Briefing Note.

implementation_scotland _bn_new.pdf

This briefing note provides a summary of the EU Energy Performance of Buildings Directive and its implementation in Scotland.

Provides a useful background note on EPBD and its implementation.

Greenpeace (2007) Decentralising Scottish Energy: Cleaner, Cheaper, More Secure. Energy for the 21st Century Application of the Wade Economic Model to Scotland. London: Greenpeace


This report argues that Scotland is highly-suited to a renewably supported but decentralised grid system. Its renewable energy is well-known, but it has a relatively high heat demand from buildings that require local heating - buildings that could harness the byproduct of electricity generation from gas or oil. The economic model put together for Greenpeace by the World Alliance for Decentralised Energy ( WADE) shows what is possible. This model has been used by the UK Foreign and Commonwealth Office as well as the European Commission and governments or agencies in Germany and Canada (see page 9). It shows that decentralising power generation in Scotland over the next 20 years delivers a saving of 8% on both CO 2 emissions and on gas use compared with a scenario in which a continuation of centralised power and the renewal of nuclear reactors is relied upon - and all at a lower cost.

Describes the scenarios that have been used to compare the impacts of adding new generation capacity in Scotland either through DE or through CG, in terms of costs, CO 2 emissions, and fuel use and dependency. The Annexes give a more detailed overview of the assumptions made and show the exact inputs used in the different scenarios. Annexes to the report can be found at


Fuel price increases were set at 0.5-3% per year (the rate of growth depending on the fuel; coal price rises at 0.5% per year being lower than gas price rises at 3% per year) compounded over the whole 20 years, except in the fuel price sensitivity scenarios where these assumed rates are varied

Scottish Executive (2007) Energy Efficiency and Micro-generation: Achieving a Low Carbon Future. A Strategy for Scotland. A Draft for Consultation.


This first Energy Efficiency and Microgeneration Strategy for Scotland sets out the Executive's aims for improving energy efficiency and encouraging a greater uptake of microgeneration. The Executive's Sustainable Development Strategy - Choosing Our Future (November 2005) and Scotland's Climate Change Programme - Changing Our Ways (March 2006) provide the backdrop to the development of this Strategy. They both reinforce the need for action to ensure that the vision for Scotland in 2050 as a prosperous and sustainable low carbon economy is secured. The strategy states that all buildings must incorporate, as standard, much higher levels of energy efficiency and low carbon technologies to bring about a reduction in carbon dioxide emissions. Specifically, the Executive is committed to improving the energy efficiency of Scotland's homes. Domestic sector consumption is rising more rapidly than the rest of the Scottish economy and is now the single largest energy user - in 2002 the sector accounts for 34% of all energy use. Scottish domestic energy use per capita is higher than the average for the UK. Energy used in the domestic sector in Scotland accounts for over 10% of the total UK domestic consumption, however Scotland only has 8.5% of the UK population.

Sets out the previous administration's aims for improving energy efficiency and encouraging a greater uptake of microgeneration. Had gone out to consultation before change of government.

In the residential sector, 80% of energy used goes towards heating and the potential to reduce emissions is therefore significant.

Scottish Government (2007) Firm Foundations: The Future of Housing in Scotland. Edinburgh: Scottish Government


This discussion document affirms the Governments vision for the future of housing in Scotland and sets out proposals for realising that vision. These proposals include:

  • Increasing rate of new housing supply to at least 35,000 per year
  • Launching a Scottish Sustainable Communities Initiative
  • Establishing a Low-cost Initiative for First Time Buyers
  • Setting an agenda for the private rented sector
  • Improving the choice for homeless people
  • Heralding a new role of local authorities as social landlords
  • Safeguarding the future of all new social housing
  • Improving the supply of new housing association houses
  • Improving the choice and supply of affordable homes
  • Monitoring progress in compliance with the Scottish Housing Quality Standards
  • Modernising the regulation of social housing.

The house-building rate in Scotland has been relatively steady at around 25,000 a year for the whole of this decade, with no significant response to increased demand. House prices were 72% higher in 2006 than in 2002, but the level of new build increased by only 2% over the same period. The last quarter of a century has seen a transformation in tenure. In 1982, only a minority of households were owner occupiers, a far smaller share than the social rented sector. By 2005, however, owner occupation was the tenure of 67% of the housing stock. Although this pattern of change is seen across most of Europe, the change has been most dramatic in Scotland, where the level of owner occupation has risen by 31% since 1982.

Provides a framework for the DEMScot study by setting out a vision for the future of housing in Scotland.

Challenges Scotland's local authorities, developers and builders to increase the rate of new housing supply in Scotland to at least 35,000 a year by the middle of the next decade (2015).

As owner occupation has grown in popularity, social housing as a whole has declined as a proportion of the total housing stock - from over 50% in 1981 to its current level of around 25%.

Scottish Government (2008) Consultation on Proposals for a Scottish Climate Change Bill. Scottish Government: Edinburgh


The aim of the proposed Scottish Climate Change Bill will be to establish a framework to drive greater efforts in Scotland. The Bill will create mandatory climate change targets to reduce Scotland's emissions and will create new legislative means to do so. This will provide business and society with a clear signal from Government of its seriousness in tackling this issue and will provide Scotland with the certainty it needs to make the right choices now. The Bill will signal to the international community Scotland's serious intent to contribute to the global effort to mitigate climate change and provide a strong example to other countries showing what can be done.

The Scottish Government is currently considering the Low Carbon Building Standards Strategy for Scotland report which recommends measures to make new and existing buildings in Scotland more energy efficient. As new buildings only represent 1% of the building stock each year, the Government is also considering the role for standards for existing non-domestic buildings and housing stock and it is the intention to consult separately on new policy proposals. The Scottish Climate Change Bill could, if necessary, provide an appropriate vehicle for these policies if it is determined that new legislation is required.

Provides a long-term framework for actions to tackle climate change and guide Scotland towards a low-carbon economy. Proposes a specifically Scottish target that takes account of its individual situation and drives Scottish policies.

References the final volume of the Scottish Energy Study - Volume 5 - which covers energy projections, and is being currently being further updated with an expected to publication of findings in the first half of 2008.

Planning policy already sets a target for on-site low and zero carbon equipment to reduce CO 2 emissions by 15% below the standards in Scottish building regulations and consideration is being given to extending permitted development rights so that more microgeneration equipment can be installed on existing buildings without applying for planning permission.

Greenhouse Gas Inventories for England, Scotland, Wales and Northern Ireland: 1990-2005 are available from:


Scottish Government (2008) Adapting our ways: Managing Scotland's Climate Risk. Consultation to inform Scotland's Climate Change Adaptation Framework Edinburgh Scottish Government.


The Spending Review 2007 committed the Government to producing Scotland's first strategy to address climate change adaptation. The Government proposes to identify strategic principles and priority actions in the forthcoming Scotland's Climate Change Adaptation Framework as a means of providing leadership, guidance and consistency of approach to government and non-government decision-makers. This document forms the first stage of the consultation process and proposes the following strategic principles for climate adaptation:

  • Adaptation should be through actions that build resilience
  • Adaptation should be continuous and responsive to new information
  • Adaptation should be integrated into normal development and implementation practices
  • Adaptation should be integrated at an appropriate scale and involve relevant levels of decision making
  • Adaptation must be addressed alongside actions to reduce emissions
  • Adaptation by one sector should not restrict adaptation by other sectors.

Scottish Government (2008) Energy Efficiency and Micro-generation: Achieving a Low Carbon Future. A Strategy for Scotland. The Scottish Government Response. Edinburgh: Scottish Government


A draft Energy Efficiency and Microgeneration Strategy for Scotland was published for consultation by the previous Administration in March 2007 in order to gather views from all sectors on current and future energy efficiency and microgeneration policy in Scotland. A Consultation Analysis Report of the responses was prepared providing a breakdown of respondents and an analysis of the main findings from the responses.

Scottish Government (2008) Scotland's Climate Change Programme - Second Annual Report. Edinburgh: Scottish Government.


Changing Our Ways - Scotland's Climate Change Programme - was published in March 2006. This strengthened the original Scottish Climate Change Programme published in 2000 and set a framework for delivering carbon savings from devolved policy measures in 2010. This is the second annual report on progress. The purpose of this second annual report is to provide a factual report on policies and programmes across government which contribute to carbon savings or adaptation measures. The latest available emissions data relates to 2005 and was published in September 2007. This shows that Scotland's net emissions of carbon dioxide equivalent (CO 2e) in 2005 were around 54 million tonnes. This is approximately 0.2% of global CO2 emissions and 0.15% of global greenhouse gas emissions due to human activities. Between 1990 and 2005 CO 2 emissions reduced by 12.5%, predominantly due to economic restructuring and afforestation, and non- CO 2 gases reduced by 25.3%, predominantly from a decrease in CH4 (methane) emissions from landfill and N2O (nitrous oxide) emissions from fertilisers, as well as a decrease in deep mine emissions. The overall reduction in net greenhouse gas emissions in that period was 15.4%.

Scottish Government has committed to a 80% emissions reduction target by 2050 in Scotland.

An interim target to reduce emissions by 2011 was also set out in the Government Economic Strategy in November 2007.

Scottish Government (2008) Scotland's Renewable Heat Strategy: Recommendations to Scottish Ministers. Report of the Renewable Heat Group ( RHG). Edinburgh: Scottish Government.


The Forum for Renewable Energy Development Scotland's ( FREDS) vision is for a smarter, greener, warmer Scotland, building a commercially viable, diverse renewable heat industry to serve Scotland's heat needs. This vision is driven by both the need to tackle climate change and the potential for renewable heat to deliver sustainable economic growth. Renewable heat should be taken forward within the context of an overall heat strategy, contributing to a low carbon and energy efficient future.

. The group believes that the goals of a renewable heat strategy should be to:

  • Create diverse, stable, viable, sustainable heat markets and associated industry
  • Develop a supportive policy, planning and regulatory framework
  • Set a target for the minimum percentage of heat to come from a mix of renewable technologies by 2020
  • Support the development of integrated local and regional community energy and utility cross-sectoral partnerships;
  • Create a flexible, future-proofed delivery infrastructure (allowing for technological, financial and structural innovation).

The report includes a heat map of Scotland. The map provides a very broad-brush indication of heat demand and potential supply. At a Local Authority level, heat mapping could provide a useful planning tool, in considering existing heat use and zoning of new developments.

Between 1990 and 2002 domestic energy consumption across the UK increased by around 12%. This is counterbalanced by increasing energy efficiency and insulation, and as housing stock improves, by 2020 overall heat demand should be starting to decrease, assuming that improvements in the existing stock outweigh the net effect of additions to the stock. The higher the standards of new dwellings the less demand will be added, and the easier it will be for reduced demand in existing buildings to result in net reductions in demand.

The range of renewable heat technologies available for use today is extremely diverse. The principal technologies considered are:

  • Biomass combustion
  • Heat pumps
  • Solar heating
  • Geothermal aquifers
  • Renewable energy from waste
  • Anaerobic digestion
  • Landfill gas
  • Wind-to-heat.

There are around 2.4 million households in Scotland, using on average 20 megawatt hours of heat energy (MWhth) each per year.
Table 1 shows the estimated heat energy consumption by sector. For the domestic sector, estimated heat energy for space heating is estimated at 36 TWh/yr whilst estimated heat demand for hot water = 11 TWh/yr making a total heat demand of 47 TWh/yr. This is about 87% of total energy use in the sector.

Table 3 shows breakdown of new build properties in 2006 by owner. Private sector = 20,318; Housing associations = 4,441; public authorities - 6.

Sullivan, Lynne (2007). A Low Carbon Building Standards Strategy for Scotland. Report of a Panel appointed by Scottish Ministers.


This Low Carbon Building Standards Strategy sets out a vision for the way the building standard system and policies in Scotland should develop over the next ten years and beyond. It provides a route map that will lead to low and eventually total-life zero carbon buildings and recommends future developments in building standards in relation to carbon emissions from, and energy use in, buildings. Key recommendations for new buildings:

  • Net zero carbon buildings ( i.e. space and water heating, lighting and ventilation) by 2016/2017, if practical.
  • Two intermediate stages on the way to net zero carbon buildings, one change in energy standards in 2010 (low carbon buildings) and another in 2013 (very low carbon buildings).
  • The 2010 change in energy standards for non-domestic buildings should deliver carbon dioxide savings of 50% more than 2007 standards.
  • The 2010 change in energy standards for domestic buildings should deliver carbon dioxide savings of 30%.
  • The 2013 change in energy standards for non-domestic buildings should deliver carbon dioxide savings of 75% more than 2007 standards.
  • The 2013 change in energy standards for domestic buildings should deliver carbon dioxide savings of 60% more than 2007 standards.
  • Backstop levels of U-values and airtightness for building fabric should be improved in 2010 to match those of Nordic countries, but consideration must be given to the social and financial impact of measures that would necessitate mechanical ventilation with heat recovery in domestic buildings.
  • The ambition of total-life zero carbon buildings by 2030.

For existing buildings:

  • Consideration of developing practical performance standards for existing buildings (aligned with the energy performance certificates).
  • Recognising the very large contribution of existing domestic buildings to carbon emissions and the need to increase effective action in this sector, the Scottish Government should continue to develop measures and targets for reducing carbon emissions from the existing domestic stock.

Likely to play an important role in informing Scottish Government policy with respect to reducing carbon emissions in buildings over next 20+ years. The panel's report sets out standards to progressively deliver carbon dioxide emission savings from buildings, with an ultimate aspiration of 'total life' zero carbon buildings by 2030.

Contains (Appendix C) a pair of research summaries including an assessment on costs and construction practices in Scotland of any further limitation of CO 2 emissions from new buildings.






Brook Lyndhurst (2007) Climate Challenge, Carbon Reduction and the Future of the Urban Form: Scottish Version. A Draft Report for the RICS. London: Brook Lyndhurst


In December 2006 the Royal Institute of Chartered Surveyors ( RICS) commissioned Brook Lyndhurst to produce a companion report to Climate Challenge: Let's get real. What must cities look like to meet the challenge of climate change? (Brook Lyndhurst July 2006). The aim of both reports is to explore some of the ways in which urban areas in the UK may need to adapt and change in order to meet the challenge of climate change and, in particular, deliver a 60% reduction in carbon dioxide ( CO 2) emissions by 2050.

Whereas the first report focused on English cities, this report investigates what three Scottish cities - Edinburgh, Inverness and Glasgow - would need to do in order to meet the 60% reduction target. Defra experimental statistics for the CO 2 emissions for 2004 for Scotland which illustrate that approximately half of carbon emissions are related to the industrial and commercial sector (46%) and the rest is approximately evenly split between road transport (25%) and domestic sector (29%). This split correlates well with the pattern of carbon emissions at a UK level. In 2005, 12.2% of electricity generated in the UK was generated in Scotland, while only 10% of electricity consumption in the UK was in Scotland. Scotland is a net exporter of electricity; in 2005 Scotland exported 14.7% of the electricity generated to consumers elsewhere in the UK.

The current Scottish pattern of energy sources shows that natural gas accounts for the largest proportion (39%), followed by petroleum for transport (27%), electricity (18%) and petroleum for the built environment (14%). The category "Other" - accounting for just 2% - represents manufactured fuels, coal, renewables and waste.

Statistical data and trends were sourced largely from Government departments ( e.g.

DfT, DTI and Defra) and, in terms of local level data for each of the three cities, local authorities ( e.g. Highland Council). The work also draws on scenario planning (Tyndall Centre, Foresight Futures, Henley Centre/Environment Agency and Contraction and Convergence). The strength of scenario planning lies in its ability to illustrate possible future 'paths', consider emerging (or possibly emergent) issues and so aid in the management of risks and opportunities The report draws upon 13 scenarios from four sources:

  • The Tyndall Centre - four scenarios - these explicitly focus on the different ways in which a 60% reduction in CO 2 emissions can be achieved by 2050. The four scenarios are based upon varying levels of economic growth and energy demand.
  • Foresight Futures - four scenarios - although not specifically based on climate change, they contain scenarios that are consistent with CO 2 reduction. They are based upon different sets of social values (either individual or community focused) and governance arrangements (either interdependent or autonomous).
  • Henley Centre/Environment Agency - four scenarios - these are focused on 'environmental futures' in the round and are based upon different visions of consumption (dematerialised or material consumption) and UK governance systems (sustainability-led compared to growth-led).
  • Contraction and Convergence - one scenario - while not strictly a scenario planning tool, this approach provides a valid and important input by virtue of its strong focus upon (social) distributional issues and equity.

Number of houses: three projections: the first based on a 'no further growth' assumption (a conservative assumption), the second based on a 13% Scottish growth rate by 2024 as per the Scottish Executive projections and lastly a 25% growth in the number of households, which is broadly in line with the UK increase projected by The Environmental Change Institute.

Assuming a target of a 60% cut in CO 2 emissions for the built environment - to come solely from the demand for energy (rather than supply) then every house would need to perform better than the Advanced Energy Efficiency Best Practice for Housing Standards (assuming a 25% growth in the number of households).

Clarke J A, Johnstone C M, Kelly N J, Strachan P and Tuohy P (2006) The Role of Built Environment Energy Efficiency in a Sustainable UK Energy Economy, Invited Contribution, UK Foresight Programme


This paper argues that energy efficiency in the built environment can make significant contributions to a sustainable energy economy. In order to achieve this, greater public awareness of the importance of energy efficiency is required. In the short term, new efficient domestic appliances, building technologies, legislation quantifying building plant performance, and improved building regulations to include installed plant will be required. Continuing these improvements in the longer term is likely to see the adoption of small-scale renewable technologies embedded in the building fabric. Internet-based energy services will see low-cost building energy management and control delivered to the mass market in order that plant can be operated and maintained at optimum performance levels and energy savings quantified. There are many technology options for improved energy performance of the building fabric and energy systems and it's not yet clear which will prove to be the most economic. Therefore, flexibility is needed in legislation and energy-efficiency initiatives.

The most immediate means of improving energy efficiency in buildings is to improve the quality of the building fabric and to improve energy awareness. However, in well-insulated, well-run buildings, these options are not available. Instead, technology-focused solutions need to be adopted. These fall into two categories:

  • Passive technologies like advanced glazings and solar thermal collectors make use of sunlight to provide heat and light and the movement of air to provide ventilation.
  • There is a huge range of active technologies that could be deployed in buildings ranging from variable speed drives on fans and pumps through to advanced, active glazing and facades.

English Partnership (2007) Carbon Challenge Standard Brief. London: English Partnership


The Carbon Challenge has the principle aim to accelerate the house building industry's response to climate change. It is being delivered by English Partnerships on behalf of the Department of Communities and Local Government. The Carbon Challenge will assist house builders to develop the skills and technology needed to meet the 10-year environmental goals being set by Government for new housing development. This Challenge will act as a testing ground for the Code for Sustainable Homes and the new Planning Policy Statement on climate change

The Carbon Challenge generic brief provides a useful reference frame for the development of DEMScot - specifically the section dealing with Code Level 6 energy criteria.

The Carbon Challenge requires developers t consider the impact of likely future temperature trends and generally to build in future flexibility to allow homes to respond to climate change.

It is a requirement of meeting Level 6 of the Code for Sustainable Homes that homes have a heat loss parameter below 0.8W/m2. Heat loss parameter ( HLP) is the design heat loss per unit area per degree and is calculated by SAP. The target is demanding and is likely to require air infiltration rates of around 1m3/hr/m2@50Pa and U-values well in excess of limiting values in Part L1A Table 2 as well as careful detailing of thermal bridging.

Lomas K, Oreszczyn T, Shipworth D, Wright A J and Summerfield A J (2006), Carbon Reduction in Buildings ( CaRB) - Understanding the social and technical factors that influence energy use in UK buildings. Paper to RICS Annual Conference, London 2006.


Attempts to reduce the energy consumed in UK homes have met with limited success. One reason for this is a lack of understanding of how people interact with domestic technology - heating systems, lights, electrical equipment and so forth. Attaining such an understanding is hampered by a chronic shortage of detailed energy use data matched to descriptions of the house, the occupants, the internal conditions and the installed services and appliances. Without such information it is impossible to produce transparent and valid models for understanding and predicting energy use. The Carbon Reduction in Buildings ( CaRB) consortium of five UK universities plans to develop socio-technical models of energy use, underpinned by a flow of data from a longitudinal monitoring campaign involving several hundred UK homes. This paper outlines the models proposed, the preliminary monitoring work and the structure of the proposed longitudinal study. Two approaches to addressing the problem of modelling the socio-technical factors affecting energy use in homes are being explored - one is based on the development of enhanced occupancy models for use in BREDEM-based models and the other on a radically different approach - using Bayesian Belief Networks.

Throws light on socio-economic or technical issues that impact upon energy/carbon use and might explain differences between theoretical and measured results.

The CaRBBBN model allows estimations of the likely annual energy use (or carbon emissions) nationally, for a specific community, or for an individual home. The model will also show which variables, or combinations of variables, have the greatest impact on home energy use and the size of that impact. Policies and programmes can then be developed to target these variables.

Enables the quantification of trends due to both intrinsic factors (such as socio-economic changes in the household, changes in the ownership and usage of appliances, or energy efficiency measures) and extrinsic factors (such as rising fuel prices or energy awareness campaigns) - such factors can be seen as natural interventions. The current energy use, and data about the socioeconomic make up of each household, appliance usage and the physical form and construction of the house, provide the baseline data against which changes can be charted.

Presents data on average UK household carbon dioxide emissions by end use type (1990-2003)

RIBA (2007) Climate Change Briefing. London: RIBA


Provides a useful background briefing on climate change and, specifically, on key features of the UK strategy to mitigate climate change by reducing GHG emissions and for adapting to the ("inevitable") effects of climate change. This summary briefing:

  • Outlines the basic mechanisms and likely effects of climate change
  • Summarises international and UKGHG emissions reductions targets
  • Highlights the contribution of buildings to the UK's national GHG emissions, and the effect of growth and replacement rates
  • Signposts the RIBA's key climate change policies and its expectations of members for the buildings that they design and specify.

Frames and defines the policy agenda in the domestic carbon emissions sector in response to the climate change challenge, providing a source of reference on the scale of the challenge together with likely building-related actions, costs and benefits.


RIBA (2007) Low Carbon Design Tools London: Royal Institute of British Architects


Carbon dioxide is one of the major greenhouse gases; low carbon buildings are designed to produce significantly lower carbon dioxide emissions than others, helping to mitigate climate change. The construction industry is facing increasing pressure to address environmental performance earlier in the design process. Planning permissions are more and more likely to require technical substantiations of how carbon dioxide emissions targets will be met. At the same time, developers are realising that early and ongoing consideration of environmental performance leads to buildings that meet the required standards by the most cost effective methods. There are many tools that may be used by the design team at different stages during the development of a project. Some cover all building types; others are specific to domestic or non-domestic buildings. This guide reviews design tools that are available for architects designing low-carbon buildings. The focus is on proven tools that are in common use in the UK.

This source is a useful point of reference for low carbon building design or assessment tools with application to the domestic sector

Emissions reductions on the scale needed are likely to require:

  • Insulation of all unfilled external cavity walls
  • Insulation of all lofts with 300 mm thick mineral fibre or equivalent
  • Insulation of 15% of solid walls
  • Installation of high performance windows throughout the stock
  • Installation of, on average, two low or zero carbon technologies in every dwelling. These could include solar water heating, solar photovoltaics or micro- CHP.

RIBA (2007) Low Carbon Standards and Assessment Methods London: RIBA


This document provides an overview of recommended low carbon performance standards and associated assessment methods for new and existing buildings. These standards are generally more challenging than the minimum regulatory standards, and they are recommended for adoption by architects in order to reduce the greenhouse gas emissions associated with energy use in the buildings they design.

This source provides a valuable frame of reference for low carbon standards and assessment methods with application to the domestic sector.

Summerfield A J, Firth S K, Wall R, Lowe R J and Oreszczyn T (2006), The Case for Joined-Up Research on Carbon Emissions from the Building Stock: adding value to household and building energy datasets. Paper to RICS Annual Conference, London, 2006


This paper argues that the corollary of formulating effective joined-up government should be joined-up research: the complexity posed by policy related research questions requires analysis that encompasses diverse datasets from numerous sources. To reach UK objectives for reducing carbon emissions, it is argued that joined-up research on energy use in buildings is essential to develop and support government policy initiatives. The Carbon Reduction in Buildings project has begun a process of integrating or organising existing building energy datasets into a coherent structure for the domestic sector. In addition, it is proposed to archive these for researchers via a building data repository that would facilitate joined-up research more widely.

When average SAP values for dwellings in each UK local authority area are plotted against their gas consumption there is no evidence of a relationship. Such results underline the need for a better understanding of occupant lifestyle factors influencing energy consumption, as well as the physical data underpinning the description of the stock, such as refining the algorithms for hot water consumption or lighting.

The potential of using GHA and HCS surveys to investigate social factors influencing carbon emissions associated with dwellings is severely compromised both in terms of the relationship with SAP rating and by the lack of data on actual energy usage or internal temperatures, even for a sub-sample of participants in these surveys. CaRB proposes to recommend ways to rationalise the dwelling classification so that they are at least compatible - a process that parallels the harmonisation already undertaken with social-demographic data of the occupants (Office for National Statistics, 2004).


UK Green Building Council (2008 ). Definition of Zero Carbon. Report of the Zero Carbon Task Group. London: UK- GBC


The report releases new modelling that shows the current definition of zero carbon is not achievable on up to 80% of new homes. Therefore, if Government wants to maintain its housing delivery targets of 3 million new homes by 2020, without watering down the level of carbon savings, the definition of zero carbon must change. This study concludes that, according to all the available evidence, anywhere from 10% to 80% of new homes may not be able to meet the current definition of 'zero carbon'. The group concluded that to maintain the ambition of the original policy a revised definition of zero carbon that allows the use of off-site solutions in certain circumstances is required

Page 15 presents a table showing a list of Low or Zero Carbon Technologies that are currently able to be considered by SAP.

The report categorises different scales of development as follows:

  • Single dwelling
  • Cluster dwellings
  • Average house developments (25-100 units, brownfield & lower density)
  • High density urban in-fill sites (25 units- 150 units)
  • Smaller non-domestic building <1000m2
  • Medium non-domestic building <10,000m2
  • Large & mixed-use developments

The report concludes that the cost of 'zero carbon' reduces considerably as developments increase in size.

  • Larger developments tend to find it easier to comply.
  • Mid-sized developments can often achieve zero carbon on-site; however cost effective technology options reduce at the smaller end of this scale. Some technologies are not currently available in the UK.
  • Smaller developments can achieve zero carbon heat, but have limited ability to generate significant amounts of renewable electricity.
  • Non-domestic developments often have a significantly greater electricity demand, thus increasing the cost of achieving 'zero carbon'
  • According to Renewables Advisory Board Report (Aug 2007) the average predicted cost per dwelling for renewable energy to deliver a zero carbon home = £6000.






Allen, S.R., G.P. Hammond and M.C. McManus, 2008. Prospects for and barriers to domestic micro-generation: a United Kingdom perspective, Applied Energy, 85 (6): 528-544


Approximately 38% of current UK greenhouse gas emissions can be attributed to the energy supply sector. Losses in the current electricity supply system amount to around 65% of the primary energy input, mainly due to heat wasted during centralised production. This paper argues that micro-generation and other decentralised technologies have the potential to dramatically reduce these losses because, when fossil fuels are used, the heat generated by localised electricity production can be captured and utilised for space and water heating. Heat and electricity can also be produced locally by renewable sources. It is concluded, however, that while micro-generation has the potential to contribute favourably to energy supply, there remain substantial barriers to a significant rise in the use of micro-generation in the UK.


Association of Environmentally Conscious Builders (2006). MinimisingCO 2Emissions from New Homes: A Review of How we Predict and Measure Energy Use in Homes. London: AECB.


The AECB's research demonstrates that we are:

  • Significantly underestimating future energy use in new homes;
  • Passing up once-in-a-generation opportunities to make large low-cost savings in CO 2 emissions from new homes;
  • One-third of the homes which will exist in 2050 will be built between now and then so that storing up large and avoidable rises in CO 2 emissions -

An integrated programme of high energy performance standards for new homes would save cumulatively the emission of 600 million tonnes of CO 2 by 2050 compared to business as usual. This is around four years' total emissions from the domestic sector at current levels. The proposed programme applies to new dwellings only. The application of the Standards to non-domestic buildings, or to existing buildings of either category, would further increase the saving. The report demonstrates that the UK appears to be underestimating the potential savings from improved thermal envelope standards in particular, and improved energy efficiency standards in homes in general. More importantly, our research shows how energy and climate change policies are in danger of being distorted by failures to correctly predict and measure energy use in homes.

Identifies specific strategies - in this case an integrated programme of high energy performance standards for new homes - which DEMScot might be called upon to help test and evaluate.

The underlying data for BREDEM was gathered during the course of government sponsored programmes for monitoring energy use in homes in the late 70s and early 80s. These included half-hourly monitoring of indoor and outdoor temperatures, detailed records of heating and water use and controls, and social studies of how people lived. These programmes have not been repeated since, so over the last 20-25 years and five successive amendments to the Building Regulations, the data on which BREDEM is based have gradually moved away from real measurements to theoretically calculated data. Emissions reductions which are expressed as a saving of one set of Building Regulations over another, e.g.ADL1-2006 over ADL1-2002, are in effect comparing theory to theory.

Gas consumption will roughly equate to space and water heating in homes heated by gas, with probably some additional usage for cooking. But in dwellings which are electrically-heated, it is not possible to distinguish between space and water heating, lighting and appliances consumption.

An integrated programme of high energy performance standards for new homes would save cumulatively the emission of 600 million tonnes of CO 2 by 2050 compared to business as usual.

Presents a critique of BREDEM and SAP (page 8)

Bell M & Lowe R J (1999) Sustainability and the Development of an Energy Efficient Housing Stock: a review of some of the theoretical issues. London: RICS.


Global stabilisation of carbon emissions may require emission reductions of 60 percent in the first half of the next century and governments are placing increasing importance on energy efficiency in carbon abatement policies. However a large gap exists between what is possible and what has been achieved to date. This paper seeks to discuss the fundamental issues which should be addressed in the definition and application of energy efficiency policy designed to close the gap. It also addresses the likely impact of take-back effects The paper argues that despite the considerable work on the problem, the mechanisms which determine the propensity of individuals and organisations to invest in efficiency improvements are not well understood and that greater attention should be paid to motivational factors if a more complete understanding is to emerge.

Boardman B, (2005) Policy Packages to achieve demand reduction. Paper to European Council for an Energy Efficient Economy ECEEE Summer Study, Mandelieu France.


In many sectors and many countries, energy demand is still increasing, despite decades of policies to reduce demand. Energy use in the residential sector is rising more quickly than in the UK economy as a whole. Total UK energy demand has grown by 7.3% between 1990 and 2003, but residential energy consumption grew by an astounding 17.5% over the same period The gradual turnover of the housing stock and insulation improvements have reduced building heat loss by 31%, per household. Further gains in efficiency have come from the installation of condensing gas boilers (less wasted heat energy), though these are partially offset by the demand for higher temperatures within the house. The real problem growth area has been in lights and appliances, where electricity use per household has increase by 70% in 31 years. The net effect of these trends is that, per household, energy use has declined by only 3%. The number of households has increased by 36%, so that total GB energy use in the residential sector has risen by 32% over these 31 years. This is despite considerable policy and investment of public funds. Controlling climate change is becoming more urgent, so there is a need to devise policies that will, virtually, guarantee demand reduction. This has to come from policy, at least in the UK, as the conditions do not exist, yet, when the consumers will 'pull' the market for energy efficiency or the manufacturers will use technological development to 'push' it. That virtuous circle has to be created by a mixture of consumer education and restrictions on manufacturers (for instance, permission to manufacture). The wider policy options include higher prices for energy and stronger product policies. An assessment of the effectiveness of different policy packages indicates some guiding principles, for instance that improved product policy must precede higher prices, otherwise consumers are unable to react effectively to price rises. The evidence will be assessed about the ways in which national and EU policies can either reinforce, duplicate or undermine each other. Another area of examination will be timescales: what is the time lag between the implementation of a policy (whether prices or product based) and the level of maximum reductions. In addition, the emphasis given to factors such as equity, raising investment funds and speed of delivery also influence policy design and the extent to which absolute carbon reductions can be expected.

Identifies and analyses a range of policy packages aimed at achieving a reduction in demand for household energy.

Lesson 1: product policy should precede increased taxation and higher energy prices.

Lesson 2: product policy will not benefit the poor directly without additional, funded and targeted programmes.

Lesson 3: electricity use in lights and appliances has been the cause of major growth in domestic energy demand and

this trend is likely to continue. The resultant carbon emissions are worrying in countries, like the UK, that produce carbon-intensive electricity. Lesson 13: policy should be focused on actual energy consumption, rather than energy efficiency, in order to encourage the downsizing of appliances and actual energy savings.

Boardman B, (2006), Creating a virtuous circle for climate change with consumers, manufacturers and sufficiency. Paper to EEDAL 06 (Energy Efficiency in Domestic Appliances and Lighting, London June 2006.


Electricity consumption per household is rising due to the increasing ownership of appliances and compounded by the growth in household numbers. The resultant higher carbon emissions are causing even more climate change. Policies and perspectives need to encourage a change in this situation and ensure that higher standards of energy service are combined with declining household energy consumption. Some of this can be achieved by lower energy use per appliance, as a result of European regulation and manufacturer trends. This alone will not achieve the required energy reduction. To constrain growth, policy needs to be more actively involved with the decisions being made by appliance manufacturers and customers. Three approaches are considered in this paper: energy labels on all energy-using appliances sold; products can only be brought to market that have a proven benefit for the environment; personal carbon allowances. This will include the role of European policy, for instance the introduction of labels that are based on energy consumption (kWh) rather than energy efficiency (kWh/unit of service). For consumers, the objective of policy would be to encourage personal responsibility so that the number of energy-using pieces of equipment per household does not just continue to rise. This trend is aided by the decline in household size, both in terms of people and floor area. For manufacturers, the effects will be for the focus to switch to downsizing and to a greater awareness that innovation must benefit the environment

Boardman B, et al (2005) 40% House.ECI research report 31, Environmental Change Institute, University of Oxford, UK.


The 40% House project has investigated how the UK Government's commitment to a 60% cut in carbon emissions from 1997 levels by 2050 can be realised in the residential sector, so that the typical home becomes a '40% House'. This report summarises the main findings and recommendations of the 40% House project towards achieving this target, setting out the decisions that face policy-makers. It explores the technical and social possibilities for reducing energy demand and integration of renewable energy technologies within the building fabric, in order to propose a policy agenda for transforming the housing stock over the coming half-century. The policy pathway chosen is market transformation - the substitution of products, systems and services that have lower environmental impact than those used at present. The overarching conclusion of this project is that there is a desperate need for a clear strategy that brings housing and energy policy together, in the context of climate change commitments

Offers a scenario for existing stock in which two-thirds of the dwellings standing in 2050 are already in existence. A substantial programme to upgrade these existing houses results in an average space heating demand of 6,800 kWh per annum.

  • This requires insulation of 100% of all cavity walls, 15% of all solid walls, 100% loft insulation (to a depth of 300 mm) and 100% high performance windows.
  • The aim is to achieve as much as possible through retrofit measures before resorting to demolition, which is more disruptive and expensive.
  • The worst houses, around 14% of the current stock, are removed through a targeted demolition strategy - care must be taken not to invest money in upgrading those homes that will ultimately be demolished.
  • This requires demolition rates to be increased to four times current levels, rising to 80,000 dwellings per annum by 2016.

The report projects that

  • By 2050, the number of households will have increased to 31.8 million, housing a population of 66.8 million, with an average of 2.1 people per household.
  • The average efficiency of dwellings is a SAP rating of 80, with a SAP of 51 (the current average) as the minimum standard.
  • Fuel poverty has been eliminated, with affordable warmth and cooling for all households.
  • The needs of single people are recognised through the provision of smaller housing in appropriate locations.

The way in which the space and water heating needs of the residential sector are met is revolutionised, with an average of nearly two low and zero carbon ( LZC) technologies per household.

  • LZCs cover community CHP (combined heat and power), micro- CHP (at the household level), heat pumps, biomass, photovoltaics ( PV), solar hot water heating and wind turbines.
  • In all new build, LZCs are installed as matter of course. Existing dwellings are retrofitted when and where appropriate.
  • This would be sufficient to meet total residential electricity demand from low-carbon sources and turn the residential sector into a net exporter of electricity by 2045.

Boardman, Brenda (2007) Home Truths: A Low Carbon Strategy to Reduce UK Housing Emissions by 80% by 2050. Oxford: Environmental Change Institute.


The Low-Carbon Strategy from the Environmental Change Institute at Oxford University identifies the policies needed to deliver an 80 per cent cut in carbon emissions from UK homes by 2050. These cuts are achievable but will require a quantum leap in commitment from Government and a radical new approach. The policies have been designed not only to dramatically reduce carbon emissions, but also to be delivered equitably. The poorest households will be prioritised for assistance and fuel poverty will be wiped out. The scientific consensus is that for the UK to play its part in helping the world avoid a rise of more than 2°C, we must reduce our carbon emissions by 80 per cent by 2050. The household sector represents 27 per cent of our total emissions and achieving deep cuts here is an imperative. Its ten-point Action Plan is:

  1. An integrated strategy with legally binding targets
  2. Minimum legal standards for homes
  3. Local authorities to have a clear responsibility to ensure the carbon emissions from all energy use in all housing in their geographical area are reduced.
  4. Minimum legal standards for products
  5. Exceptional standards for new homes
  6. Reform of the energy market
  7. Financial support in the form of tax incentives and investment
  8. Roll out of low and zero carbon technologies
  9. Elimination of fuel poverty
  10. Revolution in quality, efficacy and availability of information.

Offers a vision of a society based around the low carbon house - The low-carbon house: Every household has excellent insulation. Every household has a solar installation. The individual is warmer, has more hot water and can even have more appliances than now. No household spends more than 10 per cent of its income on energy.

The report proposes specific strategies - which DEMScot might be called upon to help test and evaluate

Throws light on socio-economic or technical issues that impact upon energy/carbon use and might explain differences between theoretical and measured results

Offers scenarios for policy development against which our own scenarios could be referenced and compared

Includes useful sources of further reference such as extensive bibliographies which the interested reader/researcher might wish to pursue

Modelling by the Environmental Change Institute demonstrates that if the proposed Low-carbon Strategy is implemented in full, the emissions from UK homes are reduced by at least 80 per cent by 2050

Boardman, Brenda (2007) Examining the carbon agenda via the 40% House scenario, Building Research & Information, 35:4, 363 - 378


The task of achieving major CO 2 reductions in the residential building stock raises a wide range of policy issues, from the relationship between the rate of demolition and preserving 'heritage' areas, the standards of new build, embodied energy, roof orientation, and the provision of on-site generation. These are all vital, but the paramount task is the refurbishment of the existing building stock. In the UK, 87% of existing homes are expected to be standing in 2050, with a space heating demand that has been reduced from 14 600 to 9000 kWh per year through the provision of high levels of insulation and measures to avoid the need for air-conditioning. For all homes, old and new, major carbon reductions will require the installation of low- and zero-carbon technologies and reduced energy consumption in appliances. The scale and urgency of the task is identified, with some pointers, to progress the policy debate. The research is based on the 40% House (2005) report and uses Oxford's UK Domestic Carbon Model. Whilst most of the evidence comes from UK households, the lessons have wider ramifications, both for other sectors and for other countries. Behavioural change will be a vital component, whether from the different professions and trades involved, or from the occupants.

Throws light on socio-economic and technical issues that impact upon energy/carbon use and might explain differences between theoretical and measured results.

This paper looks at the opportunities for mitigation, using the figures in the 40% House scenario and does not discuss adaptation.

The scenario in the 40% House concept is acknowledged to be a 'best guess'. The scenario is very tight - any changes have to be matched by compensating adjustments, which are equally hard. As an example, electricity consumption in lights and appliances is nearly halved, which requires constraint by consumers and manufacturers; any slippage in the implied policies on product standards from Brussels would have to mean, for instance, the installation of more photovoltaics or more demolition to save the equivalent CO 2 .

Several data sets have been difficult to complete satisfactorily: there is little information about ventilation rates, storey heights and roof orientation. Others, such as predicted population size, have changed considerably in the last few years, partly as a result of immigration policies and increased longevity.

The 40% House scenario is so tight that there is no allowance for electricity for air-conditioning anywhere in the domestic sector.

In the 40% House scenario, the objective is for the present average level of energy demand for space heating, 14 600 kWh per annum delivered energy, to be reduced to an average of 6800 kWh per annum across the whole housing stock by 2050 (Figure 1). This is a combination of 9000 kWh per annum in refurbished properties and an average of 2000 kWh per annum for buildings constructed after 1996.

Table 1 sets outs the standard U-values to be achieved through refurbishment by 2050 for each of

  • Cavity wall insulation
  • Solid wall insulation
  • Loft insulation
  • Floor insulation
  • Glazing
  • Doors

if 40% House scenario is to be implemented.

Provides estimates of stock turnover, demolition rates and densities.

Boardman, Brenda et al (2006 ). Reducing the Environmental Impact of Housing. Consultancy Study in support of the Royal Commission on Environmental Pollution's 26th report on the Urban Environment. Oxford: ECI.


The Royal Commission on Environmental Pollution launched its study on the urban environment in October 2003, identifying four priority themes: sustainable urban transport, sustainable urban management (Local Agenda 21, EMAS, indicators), sustainable urban construction (resource and energy efficiency, demolition waste, design issues) and sustainable urban design (land use-regeneration, brown field sites, urban sprawl, land use densities). This study on reducing the environmental impact of housing forms part of the wider review, with a remit to assist the Commission with the production of its 26th Report on the Urban Environment by:

  1. Completing a literature review to synthesise and critically appraise information on the scope for the UK's housing stock to be built and/or refurbished to higher environmental standards, taking account of the wide social context
  2. Modelling the environmental impact of a range of future housing projections

The study concludes that although Ecohomes 'excellent' rating is seen as a challenging standard by the mainstream construction industry, it is still way below the standard required of new build if a 60% reduction in carbon emissions is to be attained. New buildings must be constructed to ultra-low energy standards (eg BedZED or Passive House standards), with Building Regulations set to achieve zero carbon emissions (for space heating) by 2020 at the latest. It would be helpful if standards for 2010, 2015 and 2020 were published now, to give industry a clear signal of the direction in which they need to innovate

Contains an extensive literature review. Models the environmental impact of a range of future housing projections. For the selected range of scenarios, provides a useful source of estimates of:

  • Carbon emissions from UK households
  • Carbon emissions both refurbished and new-build homes
  • Space and water heating demand
  • Electricity and gas usage in lights and appliances
  • Heat and electricity supplied by LZC
  • Comparison of embodied and operation energy for re0furbishment and new-build
  • Housing stock estimates
  • BRE estimates of carbon savings from energy-efficiency measures at low and high costs 2001-2050

Boardman, Brenda et al., (2005) 40% House Project. Oxford: Environmental Change Institute.


This document describes the main components of the computer-based UK Domestic Carbon Model ( UKDCM), developed as part of the 40% House project by a research team comprising members from the Environmental Change Institute (University of Oxford), Heriot-Watt University, and the Built Environment Research Group at the University of Manchester (formerly part of the University of Manchester Institute of Science and Technology). The aim of the UKDCM is to provide the analytical capacity for projecting energy use and carbon emissions from the UK housing stock into the future. It allows the operator to set a wide range of input variables, so that the effects of different policy choices can be evaluated in terms of the energy and carbon savings they might be expected to achieve.

Provides a summary and detailed description of the UKDCM. The UKDCM tracks changes to the housing stock - refurbishments, demolitions, new construction, installation of new technology, changing internal temperature - all in the context of a changing population, changing household size, and future variability in the UK climate (leading to changes in demand for space heating and demand for mechanical cooling).

The impact of demolition on refurbishments is accounted for in the evolving stock model, which tracks the increases in wall insulation, window improvements and loft insulation year by year.

The inherent uncertainty of the effects of climate change has led to the development by UKCIP of several scenarios of the future climate in the UK. Following the ForeSight scenarios, UKCIP have developed four future climate scenarios: low, medium-low, medium-high and high. Data from these scenarios are used to give future external temperatures, which in turn determine energy demand in the heating and cooling sub-models of the UKDCM. The operator-defined variable with regard to future climate is limited to the selection of one of four climate scenarios.

Dwelling type is specified for all existing dwellings. Dwelling type is set according to

the format of the various House Condition Surveys used in the model, and varies

slightly between different House Condition Surveys.

Scottish Dwelling Types:

  • End Terrace
  • Mid Terrace
  • Semi-Detached
  • Detached
  • Four-in-a-block
  • Tenement Purpose
  • Converted Flat
  • Tower Block

Construction type is specified for all existing dwellings as is thermal performance of main elements.

With respect to ventilation, the approach adopted uses an air change figure for dwellings based on their age class, level of double glazing, and floor area. Older dwellings are deemed to have higher air change rates than newer ones; double glazing is deemed to be more airtight than single glazing; larger dwellings are deemed to have lower air change rates than smaller ones.

BRE (2007), Delivering cost effective carbon saving measures to existing homes Prepared for DEFRA. London: DEFRA


The current technical potential, in terms of energy, cost and carbon savings (assuming all measures were to be installed immediately) was assessed first, as a benchmark. The proportion of that potential that could be met cost effectively was then estimated using four methods, based on the 'simple payback' time for each measure. Some measures appeared cost effective using all four methods (boiler and heating control upgrades, low energy lights and reduced standby consumption), but some were not indicated to be cost effective using any (the renewables measures). The rest were cost effective using some of the methods but not others. Projections were made of the rate of uptake of each measure until 2020, based on historical trends and known policy measures. The same assessment of the likely remaining technical and cost effective potential was then made and compared to the present figures to indicate what progress is likely by 2020. The results from the analysis indicate that significant progress is likely to be made between now and 2020, particularly for one of the key measures, cavity wall insulation, where it is likely that nearly all of the potential energy, fuel cost and carbon savings will have been realised. However, there is still likely to be significant potential remaining for savings from solid wall insulation, efficient glazing, floor insulation and renewable generation technologies. It is notable and perhaps not surprising that, with the exception of floor insulation, these are all measures costing thousands rather than tens or hundreds of pounds. In the case of renewables, the savings were not found to be cost effective under any of the evaluation methods used. This suggests that, unless there is a significant reduction in costs (perhaps through technological improvements, or just more efficient mass production), or an increase in fuel prices, it will be difficult to overcome this barrier without financial incentives.

Provides an analysis of existing policies in terms of their potential to deliver cost effective carbon saving measures in existing homes by 2020.

The methodology followed was:

  • Identify all significant carbon saving measures applicable to UK housing
  • Estimate the energy, cost and carbon savings for each measure per home
  • Estimate the number of homes in which each measure potentially could be installed
  • Estimate the total carbon saving potential for each measure and for all measures by multiplying the saving per measure by the number of homes in which it could be applied.

Measures identified which can reduce space heating energy consumption:

  • CWI: pre 76 homes
  • CWI: 76 to 83 homes
  • CWI: post 83 homes
  • Internal solid wall insulation
  • External solid wall insulation
  • Wall-paper type solid wall insulation
  • Loft insulation from 0mm
  • Loft insulation from 50mm or less
  • Loft insulation from 100mm
  • Loft insulation from 150mm
  • Floor insulation (suspended timber)
  • Glazing from single to C rated
  • Glazing from old double to C rated
  • Glazing from new double to C rated
  • Insulated doors
  • Draught-proofing
  • Boiler: old to A rated
  • Boiler: typical to A rated
  • Controls: room thermostat
  • Controls: TRVs

Measures identified which can reduce water heating energy consumption:

  • Cylinder insulation from 0mm
  • Cylinder insulation from 25mm
  • Cylinder insulation from 50mm
  • Boiler: old to A rated
  • Boiler: typical to A rated
  • Hot water cylinder thermostat
  • Hot water time control

Measures identified which reduce lighting and appliance energy consumption:

  • A++ rated cold appliances
  • A+ rated wet appliances
  • CFLs
  • Efficient halogens
  • Integrated digital TVs
  • Reduced standby consumption

The key assumptions for the base case dwelling were as follows:

  • Semi-detached house
  • 88.8m_ total floor area
  • U-values (in W/m_K): Walls 1.2, Roof 0.4, Ground floor 0.65, Windows 3.5, Walls 3.0
  • Gas central heating to radiators, also heating water (efficiency 73.2%)
  • Room thermostat, programmer and 50% TRVs.

The table on page 10 gives the energy, cost and carbon savings calculated per household for each measure. Details of savings calculations are presented in page 11.

Page 13 sets out the estimates of the number of homes into which each measure could currently be installed.

Page 15 presents a table of potential national carbon saving from measures in homes, together with an assessment of payback periods.

Appendices provides extended data sets.

Darby, S (2006) The Effectiveness of Feedback on Energy Consumption. A Review for DEFRA of the Literature on Metering, Billing and Direct Displays. Oxford: Environmental Change Institute.


Most domestic energy use is usually invisible to the user. Most people have only a vague idea of how much energy they use for different purposes and what sort of difference they could make by changing day-to-day behaviour or investing in efficiency. So feedback is important in making energy more visible and more amenable to understanding and control. This review considers what is known about the effectiveness of feedback to householders. The focus is on how people change their behaviour, not on the detail of the technology used. Overall, the literature demonstrates that clear feedback is a necessary element in learning how to control fuel use more effectively over a long period of time and that instantaneous direct feedback in combination with frequent, accurate billing (a form of indirect feedback) is needed as a basis for sustained demand reduction. Thus feedback is useful on its own, as a self-teaching tool. It is also clear that it improves the effectiveness of other information and advice in achieving better understanding and control of energy use. Any development of 'smart metering' needs to be guided by considerations of the quality and quantity of feedback that can be supplied. Direct displays in combination with improved billing show promise for early carbon savings, at relatively low cost. They also lay the foundations for further savings through improved energy literacy. 'Smart'or 'advanced' metering is proposed as a promising way of developing the UK energy market and contributing to social, environmental and security-of-supply objectives. Concludes that immediate direct feedback could be extremely valuable, especially for savings from daily behaviour in non-heating uses. In the long term and on a larger scale, informative billing and annual energy reports can promote investment as well as influencing behaviour. Savings have been shown in the region of 5-15% and 0-10% for direct and indirect feedback respectively.

The literature reviewed here mostly consists of primary sources, with a few review papers. Most of it comes from the USA, Canada, Scandinavia, the Netherlands and the UK. The focus is on feedback on gas and electricity consumption, with some reference to the literature on advice and information. There are not many studies of the use of feedback in the UK, or on feedback for low-income households, but these have been sought out where possible.

Using feedback requires a level of commitment to reading the meter regularly, but it has been effective as a tool in advice programmes, in conjunction with information on how to save energy, and in 'eco-team' conservation programmes. The potential savings, with motivated participants, can be in the region of 10-20% (see Table 1). Immediate direct feedback could be extremely valuable, especially for savings from daily behaviour in non-heating end-uses. In the longer term and on a larger scale, informative billing and annual energy reports can promote investment as well as influencing behaviour. Savings have been shown in the region of 5-15% and 0-10% for direct and indirect feedback respectively.

DTI Global Watch Mission (2006) Towards Zero Carbon Housing - Lessons from Northern Europe. London: DTI


The UK has committed to a long-term target of reducing emissions of greenhouse gases by 60% by 2050, compared with the level in 1997. Reducing energy use in the housing sector will be critical to the achievement of this target, since the sector accounts for 27% of UK carbon emissions. The countries visited by the mission - Sweden, Denmark and Germany - have experience of constructing housing with annual energy consumption for space heating of well below 2,000 kWh, even in colder climates. Experience in these countries shows that there are no technical barriers to the construction of low-rise housing of conventional appearance but with very low energy demand for space heating. With correct design and operation, fully acceptable comfort conditions can be provided in both winter and summer. Investigation of the application of the same design principles in medium- and high-rise housing is required. Achieving the lowest levels of energy consumption may not be cost-effective, but very substantial improvements can be made without increasing overall costs if the value of future energy savings can be capitalised. In UK social housing this may require a change in funding arrangements.

Identifies specific technical strategies for the design and operation of very low energy housing which DEMScot might be called upon to help test and evaluate.

Older housing, both low- and high-rise, has of course been refurbished in the UK, with considerable benefits for energy performance and occupant comfort. But these refurbishments have not attained the levels of performance required for the future. The demonstration in the study that older housing can be modified to PassivHaus standards is highly significant for the current project.

The data from monitoring studies indicated that while the houses had performed broadly in line with expectations, there was a general tendency for energy consumption to be higher than predicted. This is a valuable cautionary finding for policy purposes. It is clear that the adoption of PassivHaus or similar design principles is a route to significantly reduced emissions from housing but also that the gains can be over-estimated. Occupants may prefer internal temperatures higher than conventionally adopted in design procedures; they may utilise less efficient appliances etc.

Energy Saving Trust (2006) The Rise of the Machines. A Review of Energy Using Products in the Home from the 1970s to today. London: EST.


Although the energy efficiency of our homes, and the products we use within them, has improved by around 2% year on year since 1970, our insatiable appetite for energy has far outstripped this improvement. The increase in the number of energy using products - particularly consumer electronics - to be found in the average home, has made a major contribution to the rise in domestic energy consumption. In fact, between 1972 and 2002, electricity consumed by household domestic appliances in the UK doubled and is anticipated to rise by a further 12% by 2010. The potential impact this will have on our environment is huge and cannot be ignored. This review examines not only the growth of these products over the last three decades but also looks at future trends and the related policies currently in place. It offers potential solutions in the shape of the policy measures that could have the most impact in reducing energy consumption in the domestic sector.

Invaluable source of information on the installation and performance of household appliances.

If one mobile charger per household is left on standby, the energy wasted is enough to provide the electricity needs of 66,000 homes for one year.

Chapter 1.2 presents an overview of the sectors with a great deal of detailed information on the growth of household appliances and their performance

Graph 1 shows breakdown of total energy usage in the home by sector.

The percentage of total domestic electricity consumption taken up by cooking is 15%. Ovens and hobs together account for 54% of this sector's total electricity consumption, with kettles accounting for a further 27%.

Fawcett, T et al (2000) Lower carbon futures for European Households. Oxford: ECI


The aim of this report is to present policy solutions to the problem of domestic energy carbon emissions and to identify routes to lower carbon futures for European households. The report covers domestic gas and electricity energy consumption in lights, appliances and water heating ( LAWH) - all residential energy use except space heating and cooling. The detail is for the UK, Netherlands and Portugal to 2020, with a summary for the whole of the European Union. Around 3.7 MtC could be saved by 2010 in the UK, Netherlands and Portugal through policies to increase the efficiency of gas and electricity use, and to encourage fuel switching to natural gas in lighting, appliances and water heating. These savings would be achieved without any drop in the level of service provided to consumers and are delivered through the sale of more energy efficient LAWH and more gas fired appliances. The policies depend upon a strategic approach to carbon dioxide emissions in this sector that is strongly supported both in the member states and in the European Commission. Many new and innovative policy instruments have been identified to make these savings, both for energy efficiency and fuel switching, thus offering policy makers a variety of pathways to a lower carbon future.

This report covers domestic gas and electricity energy consumption in lights, appliances and water heating ( LAWH) - all residential energy use except space heating and cooling. The detail is for the UK, Netherlands and Portugal to 2020, with a summary for the whole of the European Union.

For the reference case scenario, the report includes (amongst many others) projections of:

  • LAWH electricity consumption, 1970-2020
  • LAWH gas consumption, 1970-2020
  • Carbon emissions from gas and electric LAWH, 1970-2020
  • Carbon emissions under the RC and FS- ETP scenarios, 1970-2020
  • Average annual household electricity consumption for domestic lights and appliances, excluding cooking, EU (kWh)
  • Trends in electricity consumption for domestic electrical appliances and lighting (excluding cooking): Belgium, Germany, Italy, UK
  • Total energy consumption per household by LAWH, RC, 1990-2020
  • Predicted number of households, 1998-2020 (millions)

Hinnells M (2005) The cost of a 60% cut inCO 2emissions from homes: what do experience curves tell us? Paper to BIEE conference, Oxford.


The UK has a target to reduce CO 2 emissions by 60% by 2050, and is pressing through the G8 that this target be adopted more widely. Such cuts in CO 2 imply significant policy and technical change. The Buildings sector accounts for around 22% of UK Greenhouse gas emissions and is therefore an important sector which would see dramatic change if this target is to be achieved. One vision of how emissions might be reduced to 40% of current levels is described in the 40% House report. However, the report did not discuss the costs of implementation for a number of reasons, e.g. because the costs of energy and investments could change radically over such a long period. Whilst many technologies to reduce CO 2 emissions from buildings are currently expensive, current cost effectiveness is not a good guide to future cost effectiveness. The literature on how cost of a technology reduces with time (variously described as technology learning, experience curves, and 'learning-by-doing') is reviewed. There is a significant amount of literature in renewables (especially at large scale) but little in building integrated renewables or CHP, or in energy efficiency. There has been little use of experience curves in the UK (though wide use in the US, Europe, Japan and at IEA level). The possible reasons for this are discussed. The cost of a technical change is strongly dependent on a number of factors, which are explored in the paper. In particular, policy plays an important role in the cost of change, and in allocating the cost between public sector and private investors. The change in cost effectiveness for a range of building integrated renewables, CHP and energy efficiency technologies is discussed. Under a 40% House scenario, experience curves and energy price scenarios suggest dramatic changes in cost effectiveness, bringing the payback of measures down to very reasonable levels, thus making the scenario plausible. The paper covers a range of themes of interest to the conference including: moving to a low carbon economy; demand policies; Technology and innovation; and incentives versus regulation. A key conclusion of this work is that the UK is not a mere recipient of technology learning that goes on 'somewhere else'. The UK can have significant impact on learning rates without the rest of world, but most especially in new technologies (biomass, building integrated wind, PV, and micro CHP technologies).

Throws light on socio-economic that impact upon energy/carbon use and may be used to explain differences between theoretical and measured results.

The literature on how cost of a technology reduces with time (variously described as technology learning, experience curves, and 'learning-by-doing') is reviewed.

The change in cost effectiveness for a range of building integrated renewables, CHP and energy efficiency technologies is discussed.

It is possible to envisage a scenario where the real value of the fuel savings doubled in real terms to 2050. This is not a prediction but a scenario, and might be through

  • Changes in energy prices
  • Carbon taxation
  • Cost reflective pricing ( e.g. changes to use of system charges to reflect real use of the network of electricity generated locally).

This work has shown that Current cost effectiveness is no guide to future cost effectiveness, and that Government would not get best value for money by focusing on current cost-effectiveness alone.

The impact on cost effectiveness of LZC may be that gradually over the period:

  • the running hours to provide the heat could be reduced, thus reducing the savings from LZC, or
  • the size of a given LZC installation could be reduced, thus making some saving in capital cost compared to a device needed for a given installation today.

If it is assumed that over the timeframe and across the portfolio of technologies these two effects might be about equal, then the value of the savings from LZC that supply heat (but not electricity) could deteriorate by around 18% by 2050.

The paper has drawn together evidence on three key issues to costing new technologies in 40% House:

  • For LZC in particular, improved insulation may reduce demand, and thus cost effectiveness of those technologies that supply heat by an average of around 18% by 2050
  • The value of energy savings, through increased energy prices, and internalisation of costs may have increased by a factor of 2 by 2050
  • Experience curves applied to the 40% House scenarios show many new technologies falling to a fraction of their current price.

From this, the change in costs, and benefits and therefore cost-effectiveness compared to today, can be estimated.

Currently, simple paybacks for many LZC technologies are poor (line 1 Table 3), often beyond than the life of the asset. The impact of learning (even with the reduced heat loads expected in 2050) is sufficient to bring payback periods well within the lifetime of equipment (line 2). The impact of a possible doubling of energy prices, or the EU following the 40% House path, would further bring down payback times (lines 3 and 4).

Hinnells M (2006) Enabling technologies for demand reduction and microgeneration in buildings. The Office of Science and Innovation ( OSI) Foresight Horizon Scanning energy project.


Buildings account for almost half UKCO 2, and energy demand has been growing for several decades. In the context of economic growth, population growth, smaller household size, and increasing demand for services this looks set to continue, unless there is significant change. This note outlines basic research needs and opportunities in enabling technologies for step change demand reduction in buildings through the application of the next generation of information metering and control, energy efficiency products and microgeneration. The note covers both residential and non-residential buildings (offices, retail, warehousing and public sector buildings such as education and healthcare). This wide approach has been adopted because technologies and trends tend to migrate from one building sector to another (eg IT, from offices into homes, lighting trends from offices and retail into homes) It covers technologies that can be used in new build or major refurbishment. Much of the need for change is better use of known technology, and some is behaviour. Some behaviour depends on new technologies ( e.g. metering).

Understanding how technological innovations are taken up, ( e.g. stock turnover issues, as well as how technical change occurs) and the economics of new technologies is as important as the technologies themselves.

The turnover of the stock is an important determinant of the impact of a technology in terms of potential energy savings

Energy consumption is currently increasing by up to 1% p.a., instead of a 2% reduction needed to meet White Paper objectives. The change required each year is therefore a reduction of 3 percentage points. However, only around 4-5% of our capital stock of buildings and equipment are replaced each year. Thus new capital stock needs to consume around a half of what it replaces to achieve the necessary trajectory.

Hinnells M, (2006) Achieving a 60% reduction inCO 2: Implications for micro-generation, residential lights and appliances. Paper to EEDAL 06 (Energy Efficiency in Domestic Appliances and Lighting, London June 2006,


A number of European Governments, including the UK, have a target for a reduction in CO 2 emissions of 60% by 2050 compared to 1990 levels. This paper explores the implications for residential lights and appliances and for microgeneration which are both mass produced and have the potential for significant cost reduction and market transformation. Projected consumption for lights and appliances could be halved through a combination of new technologies, fuel switching and reduced purchasing of new and energy intensive products. A focus on energy efficiency is not sufficient. Microgeneration devices generate heat and or power and are installed in the building or community. Typical devices include micro- CHP (both Stirling engine and fuel cell), community based CHP, biomass, heat pumps, solar PV, and solar thermal. Different technologies have potential in different types of housing. Microgeneration is developing rapidly in the UK. By 2050 the domestic sector could supply most of its heat and electricity from microgeneration, with conventional heating technologies (electric heating and gas central heating boilers) almost obsolete. The cost of such change is discussed. In particular, 'experience curves' show that the cost of a new product is shown to fall in a predictable way with increases in volume. Applying this approach shows that payback times fall dramatically with significant levels of uptake possible. Policy to deliver such large changes through Market Transformation is discussed. The development of Energy Services Companies could help finance the required investment. Personal Carbon Allowances and information both have a significant role to play.

New product groups with changes in technology, population structure and wealth create new marketing opportunities and consequently new energy demand. Examples are home security systems and patio heaters.

Table 1 sets out detailed assumptions for LZC under the three 40% house scenarios.

Table 2 sets out an action plan timetable for implementation of 40% house to 2050.

A basic driver is expected to continue to be more households (23.9 to 31.8M homes in 2050, up 33%) and wealthier households.

The other major issue is smaller households. Many of the new households are one person households because we are marrying later, divorcing earlier, and living longer. In the UK, based on NHBC quarterly statistics on completions, the number of homes build as detached has reduced from 85,000 to 51,000 a year (a decline of 40%) whilst the number of new flats has increased from just over 30,000 to just under 60,000 a year (a 95% increase), all in the space of just 4 years from 2000 to 2004

House of Commons Communities and Local Government Committee (2008 ) Existing Housing and Climate Change London; The Stationary Office.


The United Kingdom contains more than 26 million homes ranging from the largest Elizabethan mansion to the smallest purpose-built flat. Collectively, those homes emitted 41.7 million tonnes of carbon dioxide (Mt CO 2 ) in 2004, representing more than a quarter of the UK's emissions (152 Mt CO 2 ) of the main greenhouse gas driving climate change.1 Over the next 12 years, the Government believes that 3 million more units will need to be added to the UK housing stock, and considerable effort has been made to ensure that those additional homes are as carbon-neutral as modern building methods, technologies and government regulation can make them. The question animating this Report, therefore, is what can be done to minimise and reduce the carbon footprint of the already existing housing stock, particularly given that an estimated 23 to 25 million of the homes already standing will still be lived in half a century from now. To put it another way, two thirds of the homes likely to exist in 2050 already do. Reducing carbon emissions by 60 per cent over the next 42 years requires remarkable change in our habits, our fuel consumption and the technologies we use to build and run our homes

Housing Corporation (2008) Fit for the Future - The Green Homes Retrofit Manual


This guidance pulls together in one place the key information that social landlords need in order to improve the environmental performance of their existing housing stock.

The Guidance is in two parts. The first part, the Manual, includes:

  • Advice on adopting a strategic approach and on delivering environmental improvements in the context of a planned and responsive maintenance service.
  • Reviews of the technologies for energy efficiency, from insulation to solar and wind; including sufficient information for social landlords to identify if they should be looking into each technology further in respect of the characteristics of their particular stock portfolio.

The second part is a Technical Supplement. This provides more detailed technical information on the measures described in the Manual.

Of the total housing stock in the UK:

  • 9.1m homes have uninsulated cavity walls - 60% of homes with cavity walls
  • 6.3m have poorly or non-insulated lofts - 33% of homes with lofts
  • 1m homes still have no central or storage heating systems - 5% of housing stock
  • 3.1m homes have to use fuel other than gas, which tend to be less efficient - 14% of the stock.

Johnston, Lowe, Bell, (2005), An exploration of the technical feasibility of achievingCO 2emission reductions in excess of 60% within the UK housing stock by the year 2050 (Energy Policy vol 33, no 13)


The aim of this paper is to explore the technological feasibility of achieving CO 2 emission reductions in excess of 60% within the UK housing stock by the middle of this century. In order to investigate this issue, the paper describes the development of a selectively disaggregated physically based bottom-up energy and CO 2 emission model of the UK housing stock. This model covers both the energy demand and energy supply side and has been used to develop and evaluate three illustrative scenarios for this sector. The results of the scenarios suggest that it may be technically easier, using currently available technology, to achieve CO 2 emission reductions in excess of 80% within the UK housing stock by the middle of this century. However, achieving these sorts of reductions will require strategic shifts in both energy supply and demand side technology

Jones, C, and Hammond G (2006) Inventory of Carbon & Energy ( ICE)


Embodied energy is the total primary energy consumed during the life time of a product. It has become common practice to specify the embodied energy as Cradle to Gate, which includes all energy (in primary form) until the product leaves the factory gate. The final boundary condition is Cradle to Site, which includes all energy consumed until the product has reached the point of use ( i.e. building site).

Killip, Gavin (2008). Transforming the UK's Existing Housing Stock. Report for the Federation of Master Builders. Oxford : Environmental Change Institute.


This report sets out some of the issues around low-carbon refurbishment and proposes some ideas and recommendations for government and other stakeholders to consider. Much more work is clearly needed to bring about the transformation of the UK housing stock to meet low-carbon standards. This amounts to a completely new service provided by the SME construction industry, potentially adding between £3.5 billion and £6.5 billion to the existing market for housing RMI (£23.9 billion). A new kind of service is needed, combining new and traditional skilled trades in ways which result in low-carbon refurbishment. Many S/ NVQs will need to be amended so that awareness of energy and carbon issues among the SME construction industry is significantly improved and practices changed to meet these new requirements. Innovations are needed in mainstream training provision, beginning with a review of innovative short courses. Product supply chains will also need to be developed. With strong leadership, adequate resources and a clear strategy, such a process might be possible within ten years.

Helps to frame and define the policy agenda in the domestic carbon emissions sector in response to the climate change challenge, providing a source of reference on the scale of the challenge together with an estimate of the costs and benefits of selected actions.

Describes the assumptions behind and the conclusions from several studies since 2003 that have used computer models and scenarios to explore the feasibility of achieving deep reductions in CO 2 emissions from housing by 20501.


Peacock A.D., Banfill P.F., Newborough M., Kane D., Turan S., Jenkins D., Ahadzi M., Bowles, G., Eames P.C., Singh H., Jackson T., Berry A., (2007), ReducingCO 2emissions through refurbishment of UK housing. European Council for an Energy Efficient Economy ( ECEEE) Summer Study, Côte d'Azur, France 4-9 June 2007


A methodology has been developed for assessing the CO 2 emissions attributable to intervention sets. The contribution of demand side measures outweigh supply side measures. Sensitivity analysis can be performed on these intervention sets based on external factors studied. This methodology is being extended to consider other performance metrics

Presents an overview of Tarbase - and relates their experience on what works in modelling CO 2 from housing.

For selected housing variant presents data on:

  • cumulative annual carbon emissions from fabric, ventilation and appliances
  • cumulative emission savings from different demand side interventions
  • cumulative emission savings from different technological interventions
  • effects of dwelling temperature on CO 2 emissions for different intervention sets
  • effects of consumer electronics growth on CO 2 emissions

Pett, J., and Guertler, P., 2004. User behaviour in energy efficient homes: Phase 2 report. The Association for the Conservation of Energy, London

202%20report ]

"User behaviour in energy efficient homes" or "User Behaviour" for short, is a research project that aims to improve understanding of how people actually use the energy efficient systems installed in their homes. Do they use them efficiently? Do they gain the benefits assumed by those who install them and the policy benefits such as contribution to CO 2 emission reductions assumed by the government programmes that supported the installations? The following findings are made in relation to the hypothesis of user behaviour in energy efficient homes:

  • Most respondents (86%) get the Desired Results from their heating systems
  • 23% use their heating systems in a way that corresponds to policy expectations, i.e. are Efficient;

o 89% of these get the Desired Results

  • 50% do it in a way that is efficient from their own perspective; i.e. they get results in a way that suits them and their lifestyle, i.e. is Reasonable;

o 96% of these get the Desired Results

  • The remaining 23% are Inefficient; they do not use the systems effectively and they do not get the best value for their lifestyle;

o Only 55% of these get the Desired Results

Throws light on socio-economic and technical issues that impact upon energy/carbon use and might explain differences between theoretical and measured results

Presents the survey's findings on respondents' demographics, previous and current heating system experience, heating controls and heating pattern, use of their current system and energy advice received, their level of energy awareness and the impact of their homes on their lives.

Lists a useful set of references on existing work identified as relevant to the study of user behaviour on energy consumption n homes. Also identifies gaps in current knowledge.

RCIS, 2008. The Greener Homes Price Guide, London: RICS

[Not available on Internet]

The authors contend that there is insufficient emphasis on the economic viability of 'greener' upgrades for homes. They say this tarnishes the concept of greening homes. This book explains what work is needed to upgrade insulation, and approximately how much it will cost. It also gives rough costs for improving energy efficiency.

It lists approximate costs of new heating systems and renewables, and possible savings resulting from this equipment, along with payback periods. There is also information on grants from local authorities, VAT and regional cost variations - including the higher average costs in Scotland. Also costs for renewable fuels.

We should adjust known UK costs for upgrades or renewables to reflect higher average construction costs in Scotland.

We have robust data on upgrade and renewables costs.

Average construction costs in Scotland reckoned to be 4% higher than UK average.

Wood chips cost 1.6p-2.5p/kWh, while pellets cost 3p-3.5p.

Costs of different upgrades to, and renewables for, Terraced (42m2), Semi-Detached (84m2) and Detached (250m2) homes.

Financial savings from different upgrades and renewables (no CO 2 /fuel savings)

Shorrock, L.D., Henderson, J. Utley, J.I. (2005) Reducing Carbon Emissions from the UK Housing Stock. Garston: BRE


This report updates and extends analyses in BRE Report BR435 published in December 2001. It is concerned with the carbon emission reductions that might be possible from the housing stock, addressing this issue from three different, but related, perspectives. Accordingly, the report is in three main parts, each of which is essentially a complete report in its own right, with its own summary, references and appendix containing relevant tables. Part 1 of the report considers a wide range of energy efficiency measures and for each one assesses the potential carbon savings and their cost-effectiveness. The position that existed in 2001 in respect of each of these measures is examined, as well as looking forward to the likely situation in 2010, 2020 and 2050. Part 2 focuses on the effectiveness of energy efficiency policies within the domestic sector, using historical data to assess the savings that have been achieved and to compare the effects of the different policies. Due to the differences between the various energy efficiency policies and the analyses that are possible, the discussions in this part of the report are divided into three main sections. These analyses provide evidence that is useful for considering the likely effects and costs of future policies, which is addressed in Part 3. Part 3 looks at the potential future carbon emissions from the housing stock and considers five separate scenarios. The reference scenario describes what could happen if historical trends were to continue. The policy scenario takes account of the effects of planned energy efficiency policies. The efficiency scenario looks at what could happen if all of the standard energy efficiency measures were to be taken up as rapidly as seems feasible. Two further step change scenarios then examine how we might approach a 60% reduction in carbon emissions by 2050, as recommended by the Royal Commission on Environmental Pollution and as adopted as a goal to work towards within the Government's Energy White paper.

Sescribes a study to evaluate the carbon emissions saving potential of domestic energy efficiency measures. It considers the potential in 2001 (the latest year for which data is available), and looks ahead to 2010, 2020 and 2050.

Presents possible scenarios for future domestic energy use and carbon emissions to 2050.

The results presented in the report emphasise that, although large carbon emission savings are potentially available, they will not necessarily be easy to access and will involve quite large expenditures. In the medium-to-long term they will also require some fundamental changes to both the national energy supply infrastructure and, linked to this, to the individual energy choices that are made by the many millions of ordinary householders.

Presents findings on the effects of domestic sector energy efficiency policies on energy and carbon savings.. These policies are organised under the headings of:

  • The effects of grants
  • The effects of labelling, minimum standards and Building Regulations

For future years projections were made of likely uptake rates by fitting S-curves through past data and assuming a continuation of that trend (see Part 3)

Information was collated on the costs and lifetimes of domestic energy efficiency measures and the amount of energy saved by each was calculated using BREDEM-12. Using suitable carbon intensity factors for fuels (Table 2), energy savings were converted to carbon emission savings.

Similarly, using fuel cost factors, the cost saving for each measure was calculated. Using this information, cost-effectiveness analysis was carried out by calculating net annual cost. For each measure examined it was also estimated what number of dwellings in the UK housing stock it could reasonably be applied to (Table 3), enabling an estimate to be made of the potential national carbon saving. By adding up the potentials for each energy efficiency measure, the total potential national saving was estimated. By adding up only the potentials of the measures which had a negative net annual cost, the cost-effective potential national saving was estimated.

Costs and lifetimes of various energy efficiency measures are included (Table 1)

Southall, R (2008). Advanced Ventilation Approaches for Social Housing. Brighton: AVASH

AVASH is a collaborative project funded by the Intelligent Energy Europe ( IEE) Agency. Its aims are to survey and sample social housing within the three participating countries - to assess their current performance in terms of insulation and airtightness. Then to computer model the properties to ascertain the best ventilation and insulation upgrade strategy. Surveying the properties entailed thermo-graphic analysis to determine the extent of their thermal insulation, and a blower door test to check the air-tightness of the building fabric.

Advanced ventilation systems limit the amount of energy being thrown away when stale air is discharged from the building in winter. The amount of ventilation has to be geared to the occupancy of the building - not too much and not too little. In addition the spent moist air must have its heat removed, and reused, to limit heating requirements. As a result trickle vents will soon to become an inadequate response to the problem. Their supply of air is too uncontrolled and lacks heat reclaim.

The necessary pre-requisite for all advanced ventilation strategies is that air leakage from cracks in the building fabric is limited so the ventilation system can be engineered to precise performance

AVASH Objectives:

• To determine the best ventilation strategy for existing social housing in the UK, Ireland and Denmark, from the point of view of energy efficiency and occupant comfort.

• To propose any additional low cost measures for immediate improvement of the building's thermal performance.

Following field surveys of test dwellings, the next phase is to input the data into a computer simulation model that will establish:

  • An assessment of the feasibility of possible methods of insulation.
  • An assessment of the probability of achieving and adequate level of air tightness.
  • An assessment of the feasibility of remedially installing alternative advanced ventilation systems in terms of ease of installation, for example the location of clear vertical routes for ducts through the height of the building.
  • The change in energy performance of each type after remedial insulation, sealing and installation of the different ventilation alternatives.
  • The resulting reduction in the Carbon Dioxide emissions for which each building is responsible.

Sustainable Development Commission (2006) Stock Take: Delivering Improvements in Existing Housing. London: SDC.


This report makes an assessment of the level of savings that can be achieved by implementing a full range of technical options in existing homes. This study has identified the need for Government policy to focus on the existing stock because of the volume of properties and the significant environmental and social benefit that will derive from the range of policy interventions that we are recommending. The technical solutions are well known and simple, and many have reasonable payback times. However, a number of barriers exist which mean that these improvements are not being delivered fast enough and therefore further intervention is needed. The study identifies several themes for future action:

  • The role of Regulations and Standards in setting the baseline
  • Encouraging householder awareness and engagement
  • The need for future research
  • The need for rigorous implementation of all our policy recommendations

Proposes specific technical measures that can achieve improved resource efficiency and which DEMScot might be called upon to help test and evaluate.

These include These are: insulation (loft, walls, floors, tank and pipes), draught proofing (around windows, doors, skirting boards), secondary and double glazing, improved heating systems (complying with the new Building Regulations standards of 86% efficiency) wider use of heating controls, and efficient lighting and appliances. Installing micro-generation also reduces demand for centrally supplied energy, such as with solar hot water systems, ground source heat pumps, and photovoltaics. Micro CHP boilers allow householders to generate electricity whilst consuming gas for heating, and community wide CHP schemes provide probably the most cost effective option for reducing demand for energy in certain housing densities

Section 5.1 contains charts showing household energy consumption by end use (Fig 1) and household carbon emissions by end use (Fig 2).

Figure 3 shows the market penetration of key energy efficiency measures in the context of their potential application. This shows that although some measures such as hot water tank insulation are currently nearing maximum penetration, there is still significant potential to apply cavity wall insulation and 'top up' loft insulation.

Several studies (See Box 5) have modelled the existing and projected housing stock to 2050 and demonstrated that it is technically possible to deliver the 60% carbon cut by 2050 using currently available technology: a combination of energy efficiency and renewable technologies.

Table 3 shows good and advanced practice standards for retrofitting insulation in relation to new build standards (U-values and infiltration rates).

Table 4 shows average costs and savings from typical energy efficiency improvements.

Figure 4 and Figure 5 present delivered energy savings per measure and cost per carbon unit saved for a range of measures, respectively.

Table 5 presents costs and benefits of microgeneration energy technologies.

Tuohy P., McElroy L., Johnstone C., (2006) Sustainable Housing: the use of simulation in design. Eurosun, Glasgow


Current guidelines for sustainable housing including the EU 'Passivhaus' and UK 'Advanced' standards are reviewed along with UK building standards. Areas of divergence between the guidelines are identified in the specification of insulation level, ventilation strategy and use of thermal mass. It is shown that a simple model used to illustrate the benefit of thermal mass can also illustrate potential problems. A detailed investigation based on dynamic simulation is carried out into the performance of different constructions across a range of climates and different occupancy and gain scenarios. The results show how key parameters can affect building performance including occupant comfort, heating energy requirements and summer overheating.

Presents experience on what works or doesn't work in modelling CO 2 from housing.

The conclusion of the study is that the current guidelines have limits to their applicability and that simulation should be used in the design of sustainable housing. The simulation should consider the range of climate and occupancy scenarios appropriate to the current situation and potential future scenarios.

UK Green Building Council. (2008) Carbon Reductions in Existing Homes. London: UKGBC.


Earlier this year, the Energy Efficiency Partnership for Homes ( EEPH) proposed a piece of work which would set out how emissions could be reduced by 80% in the existing housing stock by 2050. Following discussions with Government, it was agreed that UK- GBC would direct a project that sought to fulfil EEPH's objectives, but which would also seek to assist Government in the development of its strategy. The output will be a short report in late September to inform the energy efficiency consultation as comprehensively as possible in a short space of time. The project will focus on the timeline to 2022, but noting key differences in assumptions which drive different pathways to 2050. The aim is as much confidence as realistically possible that policy solutions the project proposes to deliver to 2022 will continue to deliver savings en route to 2050

The aim of the papers is to establish what we currently know and to achieve consensus on that before developing potential solutions (both old and new) in more detail. Needs to be revisited after publication of proposed report in late September 2008.

Contains a listing of existing and proven methods under the following headings:

Demand reduction

  • Cavity wall insulation is one of the most cost and carbon effective of measures, yet 8.5 million cavities remain unfilled
  • Loft insulation also offers cost effective carbon savings. Approximately 1 million UK lofts are uninsulated and 11 million are partially insulated.
  • 1/3 of properties in the UK have solid walls; EEC2 led to the installation of solid wall insulation in just 42,000 homes. The 7 million or so solid walled homes present significant insulation challenges at higher cost than cavity fill.
  • Ground floor insulation is an emerging option which is expected to play a stronger role in the period post 2011
  • Draught-proofing and other measures to reduce air infiltration
  • Hot water tank insulation
  • High performance glazing - the introduction of window energy ratings has seen acceleration in product development so that there are now realistic choices at the A rated end of the scale (products which did not exist prior to the introduction of ratings).
  • High efficiency boilers - 80%+ market share for condensing boilers since changes to Building Regulations in 2006. Market turnover is steady with the installation of 1-1.5 million boilers per year.
  • Heating controls
  • Mechanical ventilation with heat recovery
  • Smart meters and visual display devices

Lights and appliances

  • Lighting - The Energy Innovation Review estimates potential savings from lighting of 0.9MtC/year. Between 2005 and 2008, EEC2 stimulated the distribution of over 100 million CFLs to householders. It is anticipated that, by the late 2010s, LEDs will form a significant part of low energy lighting offerings to consumers.
  • A+ and A++ rated appliances - household appliance and consumer electronics markets have been transformed in recent years through the application of product energy efficiency standards, often driven by a European framework. Market transformation is likely to continue as product standards are strengthened, accompanied by behavioural change campaigns ("switch off") which are having an increasing impact.

Low and zero carbon technologies

  • Defra's Call for Evidence on the supplier obligation identifies that 0.3MtC/year could be saved through the installation of 1.9million LZCs in the period to 2020.
  • Proven technologies currently in the market include:
  • Heat pumps (ground- and air-source)
  • CHP (community scale)
  • Solar thermal
  • Biomass boilers
  • Solar photovoltaics


World Wildlife Fund ( WWF) (2007) How Low: Achieving Optimal Savings from the UK's Existing Housing Stock. Godalming: WWF.


The How Low? report joins a growing body of research that demonstrates an 80% cut by 2050 is feasible with negligible impact on the UK economy. The IPPR, RSPB, WWF report, 80% Challenge: Delivering a low-carbon UK and the Oxford ECI Home Truths report both agree that the residential sector can meet this target, with the 80% Challenge study recommending further savings to offset growth in other sectors. While these studies don't necessarily agree on the platter of measures required to achieve the 80% cut, they suggest that the most cost-effective sustainable energy measures must be applied to the residential sector first - preferably by 2020. It will be required to deliver savings in all sectors, but the residential sector is an early and strong priority. The study examines the measures, market transformation and behavioural changes needed to achieve proposed targets. In short:

  • In order to achieve the UK's 2020 targets we will need to go beyond the short payback energy efficiency measures that feature in current policies. We will need to deploy significant numbers of low and zero carbon technologies ( LZC) and solid wall insulation.
  • The government must act now to ensure that the 80% reduction is achieved. This requires a strong set of supporting policies and financing mechanisms that support the deployment of sustainable energy measures.

Frames and defines the policy agenda in the domestic carbon emissions sector in response to the climate change challenge, providing a source of reference on the scale of the challenge together with likely actions, costs and benefits.

The carbon savings have been modelled for the implementation of two cost-effective scenarios to 2020. These scenarios are:

  • The market potential, as defined by the government's limited definition of cost-effective
  • The economic potential, as defined by any measures that recoup their upfront costs by future bill savings over their lifespan.

Two further 2050 scenarios have examined what can be achieved if all available measures are applied to the residential sector, regardless of whether they achieve net financial payback.

The report team has linearly extrapolated the projected carbon intensity of delivered electricity (2008-20) to estimate a 2050 carbon factor of 0.059kgC/kWh

Section 1.6 contains a description of the main assumptions made in the report including:

  • Discount rates and cost of carbon
  • Green gas percentage
  • Decarbonisation of electricity
  • Measures cost for LZC technologies
  • Fuel prices
  • Measures lifetimes






BRE (2007). Reduced Data SAP for Existing Dwellings. Garston: BRE


This document describes SAP 2005 version 9.81, dated January 2008 and was published on behalf of DEFRA by BRE. This manual describes the Government's Standard Assessment Procedure ( SAP) for assessing the energy performance of dwellings. The indicators of the energy performance are energy consumption per unit floor area, an energy cost rating (the SAP rating), an Environmental Impact rating based on CO 2 emissions (the EI rating) and a Dwelling CO 2 Emission Rate ( DER). The SAP rating is based on the energy costs associated with space heating, water heating, ventilation and lighting, less cost savings from energy generation technologies. It is adjusted for floor area so that it is essentially independent of dwelling size for a given built form. The SAP rating is expressed on a scale of 1 to 100, the higher the number the lower the running costs.

The Environmental Impact rating is based on the annual CO 2 emissions associated with space heating, water heating, ventilation and lighting, less the emissions saved by energy generation technologies. It is adjusted for floor area so that it is essentially independent of dwelling size for a given built form. The Environmental Impact rating is expressed on a scale of 1 to 100, the higher the number the better the standard.

The Dwelling CO 2 Emission Rate is a similar indicator to the Environmental Impact rating, which is used for the purposes of compliance with building regulations. It is equal to the annual CO 2 emissions per unit floor area for space heating, water heating, ventilation and lighting, less the emissions saved by energy generation technologies, expressed in kg/m2/year.

The method of calculating the energy performance and the ratings is set out in the form of a worksheet, accompanied by a series of tables. The methodology is compliant with the Energy Performance of Buildings Directive. The calculation should be carried out using a computer program that implements the worksheet and is approved for SAP calculations ( BRE approves SAP software on behalf of the Department for Environment, Food and Rural Affairs; the Department for Communities and Local Government; the Scottish Executive; the National Assembly for Wales; and the Department of Finance and Personnel).

Detailed coverage of how to calculate CO 2 emissions from dwellings, appliances, etc. So could be employed to check list of elements to include in model. No explicit discussion about which are the most significant determinants of emissions. No reference to modelling embodied energy. Detailed references to how ( e.g. legislatively) the documentation applies to Scotland. No references to modelling behaviour.

Detailed guidance in appendices. For instance, Appendix Q provides a method to allow for the benefits of new energy-saving technologies that are not included in the published SAP specification. Appendix R provides a set of reference values for the parameters of a SAP calculation, which are used in connection with establishing a target CO 2 emissions rate for the purposes of demonstrating compliance with regulations for new dwellings.

Energy Efficiency Partnership for Homes (2006) Measuring up the Home Energy Ratings.


Short, web-based article looking at the range of domestic energy rating systems that are used in the UK. Explains purpose of rating systems and then describes main ones in use.

Energy Systems Research Unit ( ESRU) (2006). Development of a Scottish Energy Rating Tool ( SERT). Report to the Scottish Building Standards Agency. Glasgow: ESRU .


The Scottish Energy Rating Tool ( SERT) has been constructed based on the previously developed University of Strathclyde domestic energy modelling capabilities.

The SERT methodology is based on a questionnaire survey and calculates energy performance metrics for dwellings that allow ratings to be established in order to produce certificates as required under Article 7 of the European Energy Performance of Buildings Directive ( EPBD).

The SERT method has been piloted and shown to be easy to use. It provides CO 2 emission values that are similar to, or more conservative than, other calculation tools such as Reduced data SAP ( RdSAP) when accurate input data is entered.

Concerns have been highlighted where there have been discrepancies in input data provided either by householder or from a local authority database. This has led to discussion on whether a physical survey by an accredited person may always be required for SERT. There is confidence that if an inspection by a qualified person is carried out then SERT can give the same results as the RDSAP method.

The key determinants of energy performance are defined and levels set for each of these which cover the full range for the Scottish stock both now and in the anticipated future.

For any given dwelling a two stage process is used. Firstly the appropriate levels are chosen by inference based on the energy statement and knowledge of the housing stock. Secondly, the energy performance of the dwelling is calculated. The key determinants can be grouped into the following categories: thermo-dynamic class, climate, heating systems, electrical systems, emissions factors. In order to give results consistent with other calculation tools under development several of the determinants have been aligned with UK averages e.g. gains, heating set-points, hot water demand etc.

The pilot process has also highlighted concerns with the RdSAP evaluations, which SBSA has forwarded to the developers of the tool.

The Scottish Energy Rating Tool ( SERT) enables the Energy Performance of Buildings Directive ( EPBD) CO 2 Emissions Rating ( CER, annual kg CO 2 /m2) of a dwelling to be assigned based on a Dwelling Energy Statement and the knowledge of the Scottish housing stock [see refs. 3, 4, 5] which is embedded in the tool.

Document contains extensive references in text to Scottish housing stock but only signals one source of data in the References: South Ayrshire Council housing energy database, emailed by Edgar B. 17th Jan 2006.

Hinnells et al (2007) The UK Housing Stock 2005 to 2050: Assumptions used in Scenarios and Sensitivity Analysis in UKDCM2


Web-based article reporting residential energy modeling undertaken by ECI under Building Market Transformation project. Full report at http://www.rcep.org.uk/urbanenvironment.htm

Key conclusions from modeling include:

  1. Carbon emissions vary under the three scenarios modelled.
  2. In Scenario A (current policies and technologies continued into the future, with incremental change in policies in line with current trends), emissions continue to rise and do not fall below 1996 levels for another three decades.
  3. In Scenario B, emissions in 2050 fall to 44% of those in 1996 (equivalent to the scenario modeled in the 40% House report).
  4. In Scenario C, emissions in 2050 fall to 25% of 1996 levels.

A combination of approaches eg refurbishment, demolition, energy-efficiency, building-integrated Combine Heat and Power and renewables, is necessary to deliver low-carbon housing, framed within a clear and co-ordinated strategy, with responsibility at a Local Authority level. There are important regional considerations in terms of the associated environmental impacts eg water, availability of energy sources (especially renewables), land availability, landfill resources.

A model of the UK housing stock has been constructed using data from the various housing condition surveys (English, Scottish and Northern Irish). This stock model contains a number of categories of buildings, each category representing a number of real world dwellings such that the sum of the dwellings in the stock model equals the number of dwellings in the country in 1996. In each building category is information about the building fabric (windows, walls, lofts, storey heights, air change rates etc.) and internal demanded temperatures. The majority of the information was taken from the English House Condition Survey ( EHCS) 1996 which contains structural information for almost 30,000 representative dwellings. The 1996 EHCS contained an energy sub-module which later surveys have lacked.

Using the mean UK external temperature (1970-2000), BREDEM-8 monthly energy balance equations were constructed which calculated the mean energy flows and therefore energy demands from the heating system necessary to keep a given mean internal temperature. These energy flows take account of gains from cooking, metabolism, solar and waste heat from hot water and lights and appliances.

In order to aid transparency of the modeling and results, a package of materials is available, including

  1. A spreadsheet of results from Scenarios A, B and C.
  2. The UK Housing Stock 2005 to 2050: Assumptions used in Scenarios and Sensitivity Analysis in UKDCM2. The basis for all assumptions in all three scenarios and the sensitivity analysis 2005-2050. Includes discussion of the socio-technical interactions and economic implications, and discussion of the policy framework that might bring about these scenarios.
  3. The UKDCM2 model, together with a Manual on how to install and run UKDCM2 is provided. For many users, the above outputs may be sufficient. Some users may want to explore their own scenarios and assumptions, However, in order to run the model you will need install and run IDL, Exceed and Putty (see Manual). IDL Single user licenses are available from £299, but most universities and large consultancies may already have a license. It should also be possible to run the code in PV- WAVE which is an almost identical commercially available software package. IDL is available for both Unix, Windows and MAC machines and is installed using a CD with a license key supplied by the company. PV- WAVE is usually available as a 6 month trial from www.vni.com. Please note, the model is available but we do not have the resources to support users.

Johnston (2003) A physically-based energy and carbon dioxide emissions model of the UK housing stock. Leeds: Leeds Metropolitan University


This thesis describes the development of a model which has been used to explore the technological feasibility of achieving CO 2 emission reductions in excess of 60% within the UK housing stock by the middle of this century.

This model covers both the energy demand and supply side, and has been used to develop three illustrative scenarios of energy use and CO 2 emissions; namely: a 'Business-as-Usual' scenario, which represents a continuation of current trends in fabric, end-use efficiency and carbon intensity trends for electricity generation; a 'Demand Side' scenario, which represents what may happen if the current rate of uptake of fabric and end-use efficiency measures were to be increased; and an 'Integrated' scenario which shares the same demand side assumptions as the 'Demand Side' scenario, but represents what may happen if the carbon intensity of electricity generation were to fall even further.

The results suggest that it is technically feasible, using currently available technology, to achieve CO 2 emission reductions in excess of 80% within the UK housing stock by the middle of this century.

Limited reference to occupant behaviour because "the ETP2005 scenario do not require any significant changes to occupant behaviour."

The illustrative scenarios have been constructed using a variety of external data sources. Where possible, information has been obtained from relatively uncontentious sources. Examples of such information include: population projections from the Office for National Statistics (Office for National Statistics, 2000b); mean household size data from the DETR ( DETR, 1999); details of the state of the existing housing stock from the English House Condition Survey ( DETR, 1998c); and, projections of the future energy demand of lights and appliances.

National Housing Energy Rating ( NHER) (2008). RDSAP Development .


A web-based article (unsupported by downloads, see next column).

The NHER has jointly developed the new Government-approved system for undertaking an energy survey on an existing dwelling. This system is called Reduced Data SAP - or RDSAP for short. Work started in 2003 and was split into various phases:

Phase 1 - comparing different data sets and inference rules for undertaking an energy assessment on an existing dwelling and agreeing a standard approach

Phase 2 - testing the agreed approach

Phase 3 - revisions arising from Phase 2; non-standard data collection; integration with HCR data collection; comparison with new build SAPs

Phase 4 - design of the energy performance certificate, and define how to determine the suggested improvements

Phase 5 - define the Quality Assurance requirements

Phase 6a - technical field trials including RDSAP being tested by current practising residential surveyors

Phase 6b - consumer field trials

Some of these phases are complete, some are still in progress.

Although the website says,

"In this section, you can find out more about the work and download some of the outputs"

the only download on offer is an example of the EP Certificate.

The Government has recently confirmed that RDSAP will be the methodology that will be used to produce energy performance certificates in the rented sector.

Will it be used in Scotland and Northern Ireland? The devolved administrations have yet to formally announce the methodology to be used in existing dwellings.

National Housing Energy Rating ( NHER) (2008). The EU Directive: EPCs in Marketed Sales and on Construction of Dwellings.


A web-based article explaining the EU Directive and EPCs.

No technical details on web site but provides link to approved software for SAP 2005, as of July 2008, http://projects.bre.co.uk/

Web page asks: What about Scotland? EPCs for dwellings will be implemented in Scotland as follows:

  • Construction from May 2007
  • Points of sale December 2008
  • Rental by January 2009

The relevant legislation for marketed sales is the Housing (Scotland) Act 2006 which became law on 5 January 2006 - see here for details. A Home Report will be used for this sector including a

Single Survey, Energy Report and a Property Questionnaire. The Single Survey and EnergyReport can only be carried out by RICS members.

Houses bought under Right to Buy will be exempt from these Regulations but separate regulations under the Housing (Scotland) Act will require better information about the property to be made available.

For model EPCs and the latest from the Scottish Building Standards Agency, see here.

Summerfield A J, Bruhns H R, Caeiro J, Steadman J P and Oreszczyn T (2005) Life course building epidemiology: an alternative approach to the collection and analysis of carbon emission data. RICSCOBRA '05 Conference, Brisbane


Life course epidemiology as applied in building science, where energy usage is treated as analogous to poor health outcomes, provides an alternative approach for the construction of causal models that allow for complex interactions between social and technical factors as well as long term effects. It can provide a useful framework for the successful management and analysis of longitudinal studies and may prove particularly effective in identifying the type, timing, and targeting of intervention strategies to produce optimal outcomes in terms of absolute reductions of carbon emissions and resilience of building performance to external stresses, such as those imposed by climate change. An example based on a study in Milton Keynes (London), which is currently in progress, is used to illustrate the way causal models may help elucidate the complex interactions between factors that influence energy usage.

Life course epidemiology requires the use of theoretical models to describe the set of exposures and interactions that can lead to distinct pathways through life; specifically those that result in healthy outcomes or are robust in resisting the effects of adverse exposures, compared with those that eventuate in greater disease risk or are vulnerable to external events. Thus, it provides the means to consider identifying multifaceted interventions that can provide long- term protective effects and reduce the risk of poor outcomes. Again, it may be useful to identify the factors that influence the trajectory of a building's energy performance over time; which attributes correlate with resilience or vulnerability in the face of adverse conditions; which interventions might be most effective in changing the trajectory of the building's performance.

The CaRB project is currently re-examining a study dating from 1989 where hourly energy temperature data was collected over more than 2 years for 160 dwellings located in Milton Keyes Energy Park ( MKEP). Of these, 29 houses were monitored in more detail with hourly internal temperature data and a social survey.

It can be seen that the mediating effect of building regulations on the energy usage is modified by the standard of construction (compliance, detailed finish, heating system installation, etc.) that in turn is modified by building maintenance and operation (ventilation rates, central heating times, thermostat settings, etc.). The design specifications influence household characteristics (size, age, socioeconomic status, occupancy patterns), which among other factors influence appliance usage (tumble dryer, TV, computer, etc.) and building operation. In addition, appliance usage can affect building operation ( e.g. opening windows for the tumble dryer, turning lights on when working at the computer). The relationship between household characteristics and extensions and alterations operates in both directions since the existing household specify its characteristics and the characteristics of new occupants are influenced by the attributes of the dwelling as a whole, including any extensions. Equally an interaction may occur between building operation and building maintenance.

Wright A J (2005), Development of a building energy model for carbon reduction in the UK non-domestic stock Building Simulation 2005 Conference, Montreal


The requirements for a scaleable energy model for the UK non-domestic stock are described. The model needs to be scaleable from a single building, to a community or regional level.

This work updates a large study of UK non-domestic buildings (Steadman, Bruhns et al, 2000) and their plant systems (Rickaby and Gorgolewski, 2000) in four English towns.

Approaches to using a small number of key inputs are described using inference to combine empirical models with building physics such as heat loss in a hybrid approach.

For CaRB, the model is required to:

  • predict annual energy use for all services in a wide range of non-domestic buildings
  • deal with different levels of available data input
  • include cooling loads
  • be capable of calculation for a large of buildings
  • be capable of predicting on an hourly basis for utility supply to multiple buildings.

Carbon Vision Partnership (2005) Technologies for Carbon Reduction in Existing Buildings ( TARBASE): Year 1 Report, Carbon Vision [Place of publication unknown]

Outline of early stages in TARBASE project: looking at savings from domestic and non-domestic buildings.

Possibly estimates of CO 2 emissions from their 23 house types for validation and/or curves for heating and elect demand for whole UK stock

Carbon Vision Partnership (2006) Technologies for Carbon Reduction in Existing Buildings ( TARBASE): Year 2 Report, Carbon Vision [Place of publication unknown]

Modelled a mixture of technical interventions in buildings to achieve a 50% cut in CO 2 by 2030.

Conclusion that savings of up to 50% are achievable using demand-side upgrades.

Current methods of estimating power generation from micro-wind overestimate by up to a factor of 5 [in urban areas].

Microgeneration and the carbon intensity of grid electricity are linked - as carbon intensity of grid electricity falls, there is a reduced incentive for microgeneration. Incorporate this in CE's modelling?

Maybe only seven building types need to be modelled to give adequate data for projections.

CO 2 savings from micro CHP, micro wind + PV

Confirmation for kWh heating and lighting

Carbon intensity of electricity will be from 0.28-0.48 kg CO 2 /kWh by 2030 depending on decisions about electricity mix

Forward D [ BRE] (2008) Viridian Solar - Clearline solar thermal field trial, BRE, Garston

Thorough, robust study of six solar thermal installations in real occupied homes in England (3 in Suffolk, 3 Sheffield) over 12 months. Found wide differences between hot water use (43-89l/day) and the proportion of hot water demand met by solar thermal (26-70%; 832-1440 kWh of solar energy).

Variations in hot water use were not correlated to number of occupants. The systems were 3m2, installed on new build homes.

We cannot assume a simple correlation between number of occupants and hot water demand. Behaviour appears more important.

Mean hot water use 60.7l/day/dwelling (60oC).

Mean saving from 3m2 solar water heater 1178kWh/y.

Mean yearly energy saving from using solar water heater 50.3%.

Hinnells M et al [Oxford ECI] (2006) Building Market Transformation: Second year report, Environmental Change Institute, Oxford

Outline of progress in BMT work up to half-way point. Excellent work on embodied energy/m2 in domestic and non-domestic buildings, using data from Bath University.

It is possible to model embodied energy in different [existing] house types with reasonable accuracy.

Excellent embodied energy data for validation or bottom-up modelling.

Validation data for CO 2 emissions from different house types.

Hinnells M et al [Oxford ECI] (2005) Building Market Transformation: First year report, Environmental Change Institute, Oxford

Outline of early work in BMT and description of the UKDCM2 model (United Kingdom Domestic Carbon Model version 2).

Useful suggestions for baseline modelling assumptions, inputs and outputs.

Lowe, Robert (2007) Technical options and strategies for decarbonizing UK housing, Building Research & Information,35:4,412-425

[From Abstract] The implications of some technical options for decarbonizing the UK domestic sector are explored. The main focus is on interactions between dwellings and the energy supply and conversion systems that support them, rather than on the detail of the dwelling stock. Synergies between the electricity supply system, intermediate energy-conversion systems and the dwelling envelope make it possible to achieve 60-70% reductions in CO 2 emissions with plausible combinations of existing and/or emerging technologies. Sensitivity analysis shows that a halving of the carbon intensity of the UK electricity system, plausible improvements to dwelling envelopes, and extensive use of second law energy-conversion systems (typified by, but not restricted to, heat pumps and combined heat and power) to supply space and water heating render total CO 2 emissions insensitive to demolition rates. As a result, increased demolition rates may be unnecessary to achieve deep cuts in carbon emissions from dwellings. Additional insights from this study are the strategic importance of decarbonizing the electricity system and the importance, in developing policy for this sector, of synergies between all components of the energy supply, distribution, conversion and end-use system.

Demolition rate is less important than other factors in determining CO 2 from housing.

Good idea to divide dwellings into those with aesthetic value and those without to inform take-up rates of external insulation, held to improve u-values to 0.25 W/m2K.

Solid wall properties can achieve the same thermal performance as [semi-D] cavity-wall houses.

Heat pumps and CHP can deliver major savings in CO 2 .

Data on age structure of British housing stock.

Estimates of heat loss from different parts of average British home.

Mean heat loss in 2001 was 259W/K, down from 376 in 1970.

Poss for validating Part L emissions from two house types.

Roaf S, Baker K & Peacock A (2008) Evidence on Tackling Hard to Treat Properties: A study conducted for the Scottish Government, Heriot Watt/Sistech, Glasgow

Commissioned to inform the Scottish Fuel Poverty Forum about current best practice on improving hard to treat homes, with emphasis on fuel poverty and carbon emissions.

Identifies 7 hard to treat house types. Cites LEEP study that improved thermal and other aspects of homes in Edinburgh, and measured a CO 2 nd cost savings.

There are 543,000 homes in Scotland suffering fuel poverty in 2008.

Stats on number of different house types.

Has cost data for improving blocks of flats, and some English cost data on improving mansard roofs, glazing and insulation, and low energy appliances, along with modelled energy savings.

UKERC (2003) Summary of the UKERC Energy Systems and Modelling Theme ( ESMT)

Household Workshop, UKERC, Oxford

( http://www.ukerc.ac.uk/

Compares 6 different models and research on household CO 2 emissions:


- MDM-3



- CaRB


We may be able to use ECI's DECADE model within DEMScot to assess CO 2 emissions from lights and appliances. BREHOMES does this.

Lomas K et al (2008) Carbon Reduction in Buildings ( CaRB) Third Annual Report, Carbon Vision Partnership, Leicester?

Describes progress in CaRB project, which uses longitudinal monitoring and modelling to develop tools to manage current and future carbon emissions from housing and non-domestic buildings.

Major focus on the social and behavioural side of energy use.

Carb has compiled all known datasets of measured energy use data in UK housing - amounting to 100,000 dwelling days of data.

Work also includes the DomNat survey of eight measures in home energy use: appliances, heating technologies, heating practices, clothing, ventilation practices, temperatures, energy use, and built form. Some items feature in the self-completed questionnaire. 427 households took part, of which 296 will release details of their metered energy consumption.

CaRB has also developed Community Domestic Energy Model ( CDEM), to predict energy use and f CO 2 rom groups of dwellings. This suggests there is more potential for carbon savings from heating than electrical energy.

CaRB has found that home energy efficiency is not growing as fast as expansion in energy use. Energy-intesive lifestyles are becoming 'embedded'.

There is more potential for savings in larger and high-income households

Representative survey showed average gas consumption per dwelling was 17,500

kWh/yr in the 1984 sample compared with 21,000 kWh/yr in the 2007 sample

X CO 2 (2007? [undated]) Insulation for Sustainability: A guide, X, CO 2 London

Defines 'LowHeat' standards for housing design, including a series of steps for reducing CO 2 emissions from housing, including embodied energy.

Includes lots of modelled ( i.e. questionable) data about heating energy needed with different levels of insulation and other upgrades. This includes homes built to Buildings Regulations standards from different periods, and two [currently unbuilt?] levels of super-insulation.

What factors are most significant in saving CO 2 from heating. What insulation thicknesses are needed to reach different u-values.






BRE (2006) BRE Domestic Energy Fact File 2006: Watford: BRE


This report provides information on trends relating to energy use and energy efficiency in homes in Great Britain. The information is broken down by different tenures - owner occupied, local authority. Private rented and registered social landlord.

Comprehensive historical data on energy use, energy efficiency and carbon emissions from GB homes inclusive of Scotland.

Most date is not disaggregated by region but this may be useful for the charts showing the regional distribution of housing stock by tenure (Fig 24, Fig 25 and Fig 26).

Data is provided (disaggregated by tenure) on:

  • Household expenditure on fuel, light and power
  • Households and household sizes
  • Age of housing stock
  • House types
  • Loft insulation
  • Cavity wall insulation
  • Double glazing
  • Draught proofing
  • Hot water tank insulation
  • Insulation ownership
  • Domestic energy consumption and external temperature
  • Heat loss
  • Central heating ownership
  • Heating appliances
  • Standards of comfort
  • Energy consumption by end use
  • Energy consumption by fuel
  • Carbon emissions

Full tables of data are shown in Appendix 1. The sources from which data was obtained are shown on Page 75

At 2004 there were only 8% of owner occupied dwellings in Scotland compared with 11% and 12% for other tenures (as proportion of GB total).

Department of Business Enterprise and Regulatory Reform (2007). Digest of United Kingdom Energy Statistics 2007 London: BERR


The Digest provides essential information for everyone, from economists to environmentalists and from energy suppliers to energy users.

The Digest contains extensive tables, charts and commentary covering all the major aspects of energy, including separate sections on petroleum, gas, coal and electricity. It provides a detailed and comprehensive picture of energy production and use over the last five years, with key series taken back to 1970.

Following the publication of the Digest of United Kingdom Energy Statistics 2007 on 26 July 2007, a number of typographical and other errors within the tables have come to light. These have been corrected on the web site's "Excel" versions of the tables.

Included for completeness of reference but of very limited direct value to study as data is for UK as a whole and not disaggregated by region

Department of Business Enterprise and Regulatory Reform (2008) Carbon Dioxide Emissions and Energy Consumption in the UK (Special Feature) March 2008. London: BERR


CO 2 emissions from the domestic sector fell by 5 per cent between 2006 and 2007, resulting from reduced gas and oil consumption in this sector. Since 1990 emissions have fallen by 3_ per cent, with non-electricity energy consumption in the domestic sector increasing by 3_ per cent over the same period. This is a combination of an increase in the number of households, but reduced energy consumption per household. The emissions estimates reported here for this sector do not include emissions from power stations as a result of domestic electricity consumption; domestic electricity consumption was 23 per cent higher in 2007 than during 1990.

Chart 3 shows the key sources of emissions, and how they have changed since 1990

Emissions data are expressed in terms of millions of tonnes of carbon dioxide equivalent emitted per year (Mt CO 2e/yr); this is in line with international emissions reporting. The figures can be converted to million tonnes of carbon by multiplying by the relative molecular weights (12/44)

Department of Business Enterprise and Regulatory Reform (2007) Fuel Poverty (Special Feature) June 2007. London: BERR


On the 25 May 2007 a new Fuel Poverty Indicator ( FPI) was launched. This indicator was developed by the University of Bristol to give an estimate of the level of fuel poverty in local areas. Fuel poverty occurs when a household needs to spend more than 10 per cent of its income on fuel to maintain satisfactory heating and other energy services.

The FPI is based on a complex statistical model developed by the University of Bristol. In brief, data from the 2003 English House Condition Survey ( EHCS) and property database RESIDATA were used to predict the risk of fuel poverty for different household types. The weighted model was then applied to data from the 2001 Census to provide a fuel poverty estimate for individual geographical areas

Department of Business Enterprise and Regulatory Reform (2002) Energy Consumption in the United Kingdom London: DTI


Although Energy Consumption was published in July 2002, the consumption tables which are National Statistics were updated in July 2008. This year the tables have been combined into five Excel workbooks rather than showing each table in a separate workbook


Data about actual CO 2 emissions from appliances, space and water heating, lighting and cooking - and how this relates to building design and construction.

Chapter 3 presents data (disaggregated) for:

  • Domestic energy consumption
  • Factors affecting domestic energy consumption
  • The number of households, population and income
  • Temperature
  • Growth in number of appliances
  • Cooking
  • Insulation

Department of Business Enterprise and Regulatory Reform (2008) Energy Consumption in the United Kingdom: Domestic Data Tables 2008 update


Department of Business Enterprise and Regulatory Reform (2008) UK Energy in Brief 2008


Summary of energy trends in the UK

All figures are for the UK except page 9.

Prices are presented in real terms i.e. the effect of inflation has been removed by adjusting each series using the GDP deflator.

Includes conversion factors for conversion from energy to carbon

See page 36

Department of Business Enterprise and Regulatory Reform (2008) Renewables Fact and Figures


The Department for Business, Enterprise & Regulatory Reform ( BERR) Renewables website provides information about renewable energy and the different renewable energy technologies, UK Government policy and the Renewables Obligation, UK planning policy and planning processes, and the various financial support programmes including investing in renewables technologies. There is also information and teaching resources on renewable energy sources for schools and an interactive map of UK Renewable Energy projects.

In 2007, 5% of the UK's electricity supply came from renewable sources, with 4.9% from Renewable Obligation ( RO) eligible sources.

The Scottish Executive has set a target of 18 per cent of Scotland's power to come from renewable sources by 2010 and 40 per cent by 2020.

Energy Systems Research Unit (2005). Thermal Improvement of Existing Dwellings. Report to the Scottish Building Standards Agency. Glasgow: ESRU


This report describes the outcome from a study to determine the impact of energy efficiency measures applied to the Scottish housing stock. Assuming conventional property type classifications, the present performance of the housing stock is quantified using available survey data. Building simulation techniques were then employed to generate a Web-based, decision-support tool for use by policy makers to estimate the impact of deploying energy efficiency measures in different combinations over time. The process of tool formulation is described and an example is given of tool use to identify best-value retrofitting options while taking factors such as future climate change and improved standard of living into account. The decision-support tool is a significant project output because it enables the different energy saving options to be assessed when deployed separately or together. This, in turn, will allow policy makers to assess the potential of such options in relation to the targets identified in the Government's Energy White Paper: a 20% improvement in domestic sector energy efficiency by 2010, followed by a further 20% by 2020. It also enables a rational response to the EC Directive on the Energy Performance of Buildings, which is due to be implemented by January 2006. In addition to informing the policy development process about the impact of technologies that are at present cost-effective, the tool allows consideration of options that are expected to become so only later as the 2010 and 2020 milestones are approached. It is argued that the nature of the tool renders it applicable to the cumulative roll-out of upgrade measures in the long term, both within and outwith the UK. To demonstrate the evaluation procedure, the tool is applied to two house types that represent a significant portion of the Scottish Estate. Finally, the report suggests a mechanism to monitor the cumulative impacts of upgrading measures in future in order to identify and replicate those measures that provide best value.

Most of Scotland's housing can be reduced to 40 combinations of construction options and housing type. 93.5% of homes can be represented using these combinations (pp10-11).

Excellent data on construction types, year of construction and heating fuel sources for Scottish homes. Also percentages of homes requiring improvements, cost data for different improvements, and total investment in Scotland on different sorts of improvement.

Some modelled data on CO 2 savings from different upgrades, with investment costs.

Roaf, S, Baker, K and Peacock, A (2008). Evidence on Tackling Hard to Treat Properties. A Study conducted for the Scottish Government. Edinburgh: Scottish Government In press

The aim of this report is to produce a detailed, short, and easy-to-read summary of evidence on best practice in tackling hard to treat properties to address fuel poverty and/or carbon emissions. In this report an overview of the different type of hard to treat homes in Scotland is given with an outline of their physical characteristics and methods currently used to address the hard to treat problems, which are particularly severe in Scotland. Scottish Ministers re-established the Scottish Fuel Poverty Forum to develop proposals for the reform of fuel poverty programmes within existing budgets. In order to inform the Forum's discussions, a report on best practice in tackling Hard to Treat (HtT) properties was required, with a particular emphasis on tackling fuel poverty and carbon emissions. The resulting contains the following sections. Section 1 introduces the issues that are driving the need to refurbish HtT homes. Section 2 covers the background to HtT homes and describes their types. Section 3 describes the seven different HtT buildings types that are covered in this report and outlines a range of options for treating each one of them. Section 4 describes a range of improvements applicable to most HtT properties with an overview of their relative costs and benefits where available. Section 5 summarises some new research involving innovative interventions that may be introduced in future markets including advanced surface treatments, non-technological solutions and management solutions. Section 6 outlines refurbishment recommendations for all seven of the HtT house types that include not only physical interventions but also highlight the need for management and methodological issues to be taken into account. Section 7 concludes by drawing out key recommendations from the body of the text.

Provides data about the Scottish housing stock and attribution of CO 2 emissions to different end use technologies and building elements.

Provides a summary of recommendations (Page xiv)

Presents data on

  • CO 2 emissions by end use technologies and building elements (Fig 1)
  • Intervention set for a Victorian detached dwelling (Fig 2)
  • Characteristics of Scottish Housing Stock (2003/4) (Table 1)
  • Heating energy savings from whole block improvements to tenements (Table 2)
  • Example Savings from Improvements to Individual Tenement Flats (Table 3)
  • Savings from Insulating Flat Roofs (Table 7)
  • Comparison of U-values for park homes and other domestic properties (Table 8)
  • Insulation Options for Hard to Treat Properties (Table 10)
  • Costs and Benefits of Installing Double Glazing (Table 11)
  • Costs and Benefits of Installing Secondary Glazing (Table 12)
  • Savings from Common Energy Efficiency Upgrades for Lighting and Appliances. (Table 13)

Scottish Executive (2007) Housing Statistics for Scotland. Edinburgh: Scottish Executive


The Housing Statistics for Scotland web tables contain a range of time series and summary tables available to download in Excel format

The tables were first published on 20 November 2007 and were accompanied by the Housing Statistics for Scotland 2007: Key Trends Summary.

Principal source of data about the Scottish housing stock:

  • Estimated stock of dwellings by tenure
  • New house building
  • Public authority housing stock

Total number of dwellings as at March 2007 2,427,000

Scottish Executive (2006) , Key Scottish Environment Statistics 2006, (August 2006).


Provides key data sets on the state of the environment in Scotland, with an emphasis on the trends over time wherever possible. The data are supplemented by text providing brief background information on environmental impacts and relevant legislation.

A general directory of websites that provide environmental statistics for Scotland is available at:


Data sets include:

  • Population and households
  • Electricity generation by sources
  • Annual mean temperature
  • Annual precipitation
  • New greenhouse gas emissions
  • Net carbon dioxide emissions by source

Scottish Executive Scottish Housing Condition Survey


The Scottish House Condition Survey ( SHCS) is the only national survey of housing undertaken in Scotland. It combines both an interview with occupants and a physical inspection of dwellings to build a picture of Scotland's occupied housing stock which covers all types of dwellings across the entire country - whether owned or rented, flats or houses

The key findings report for 2005/6 is available at http://www.scotland.gov

Data is organised under the following headings:

  • Key indicators of the Scottish Housing Stock
  • Energy efficiency
  • Fuel poverty
  • Housing quality

Energy Efficiency and Estimated Emissions for the Scottish Housing Stock is available to download at


This publications provides data on:

  • Emissions of carbon dioxide from domestic energy use
  • Mean emissions of carbon dioxide by tenure
  • Mean emissions of carbon dioxide by household size
  • Mean emissions of carbon dioxide by dwelling type
  • Emissions of carbon dioxide from dwellings in Scotland: weight of emissions per dwelling per year, by tenure, household type, income, type of dwelling, age of dwelling and central heating and fuel type
  • National Home Energy Rating of dwellings in Scotland: percentage of dwellings rated at each level, and mean energy rating, by tenure, household type, income, type of dwelling, age of dwelling and central heating and fuel type
  • Emission factors for carbon dioxide, sulphurous oxides and nitrogen oxides: kilograms of gas per gigajoule of delivered energy






Greenpeace (2007) WADE Model. Decentralising Scottish Energy: Cleaner, Cheaper, More Secure Energyfor the 21 st Century.


The WADE model of the electricity generation sector calculates environmental and economic impacts of meeting demand growth with varying mixes of centralised generation ( CG) and decentralised energy ( DE). Primarily spreadsheet-based, calculations are made based on a recent generation capacity, incorporating plant retirement rates and demand growth.

The inputs into the model include detailed information on energy production, consumption, efficiency, emissions, capacity, costs and load factors. As outputs, the model forecasts energy costs, including a breakdown into costs of fuel, capital, amortisation, transmission, distribution, operation and maintenance. Additionally, forecasts are made of fuel demand and emissions by fuel type, although not of aggregate fuel demand (this is an input). The model projects new generation and transmission & distribution capacity needed to meet incremental demand over 20 years covering scenarios ranging from 0% DE and 100% CG to 100% DE and 0% CG.

WADE has the advantage that it can be easily adapted to model any size of entity, from a small town to the entire world. Furthermore, it takes into account many real, but little-understood features of electricity station operation such as the impact of peak-time network losses on the amount of CG required to meet new demand.

Drawbacks of the model include a weak handling of CHP, since heat is not explicitly treated within the model, and an unrealistic assumption that transmission and distribution costs are constant on a per kilowatt basis, since this will vary greatly depending on geographic location.

For creating a baseline for energy demand, this model will have little use at the aggregate level. However, given a projection of future energy demand, this model will give a good indication of fuel demand at the disaggregated level, as it will find the likely mix that will be used to meet the given demand.

By the nature of the model, it is possible to adapt it to the Scottish energy market, provided baseline figures are known at that level of detail.

Another disadvantage of this model in relation to the work that will be undertaken in the project is that it is only able to provide a figure for the final year in the forecast period, which may have limited use for this application.

Cambridge Econometrics (2007) The Cambridge Multisectoral Dynamic Model of the UK Economy ( MDM-E3)


MDM-E3 is a highly disaggregated model of the UK economy that makes extensive use of co-integrating time-series econometric estimation, treated as panel data, allowing for all sectoral and regional fixed effects. In addition input-output tables are used, forming an essential part of modelling at the sectoral level. Economic variables incorporated in the model include consumption, output, investment, employment, income, prices, intermediate demand and trade, each of which is disaggregated into many industries.

The treatment of energy involves a disaggregation by fuel type and user. Considerations are made for technology, air temperature, energy prices, capacities, taxes and load factors.

This econometric model, with its emphasis on demand dynamics, has the advantage of being able to pick up short-run dynamics and changes in technology. The high level of disaggregation has the potential to describe the economy more accurately, allowing for different behaviour and interaction between the various sectors of the economy.

MDM-E3 adopts a 'bottom -up' approach to model the response of the electricity supply industry. This modelling approach has been reviewed by McFarland (2004) and has the advantage that it avoids the typical optimistic bias often attributed to a bottom-up engineering approach, and the unduly pessimistic bias of typical macroeconomic approaches.

The main advantage that a CGE model has over MDM-E3 is that it is better at picking up the long-run equilibrium effects in the sense of equality between demand and supply of factors of production such as labour, and capital. In addition, CGE models avoid MDM-E3's potential problem that a lack of market clearing can cumulate over time and cause large discrepancies that can throw the projections off course from the equilibrium that prevails in the world according to neo-classical general equilibrium theory. There are good grounds to suggest that the world does not operate in the manner portrayed in neoclassical general equilibrium theory and it would be misleading to rely on projections that impose these assumptions. In other words, this property of MDM-E3 that markets do not always clear is a positive attribute of the model There is more of a problem in the very long term, when such divergence can produce unfeasible effects, particularly when the forecasting period is longer than the historical series.

When compared with the WADE model, MDM-E3 has the advantage that, given appropriate historical data, it is able to provide a baseline projection for Scottish household energy demand on an annual basis. As such, this model has the potential for a useful application to the forthcoming work by identifying the time path.

Given that the model incorporates detailed and highly disaggregated time series for many aspects of the economy, with substantial portions of the forecast calculated endogenously, it should be expected that any forecast produced would be reliable and accurate, particularly in the short-term.

As mentioned in the overview, the model is especially good at forecasting in the short-term; however, the long-run error increases more than the equivalent CGE model does if the projection period is long. However, a forecast period of up to 2020 can be expected to provide robust projections, although the extension to 2050 should be viewed as broadly indicative.

University of Strathclyde (2008) Environmental Impact model of the UK - UKENVI

Based on AMOSENVI, an earlier version of AMOS (A micro-macro Model Of Scotland), this CGE model is characterised by 3 'transactor' groups, namely households, firms and government. The model incorporates 25 commodities and activities, making the assumptions that there is a single national labour market, perfect sectoral mobility and a bargained real wage function. It has been calibrated using 2000 UKIO data and is capable of dealing with both dynamic and static applications.

As with all CGE analyses, this model has strong microeconomic foundations and its flexibility allows for both policy appraisal and sensitivity analysis. However, there are limits to the model, in particular to its structure, since it pre-specifies the functional forms of the various groups and interactions. In addition, assumptions, consistent with conventional neoclassical economic theory, are imposed regarding markets and behaviours, in the form of parameterisation and calibration, rather than estimating economic relationships using historical time-series data. Importantly, there is no monetary sector and the model is closed, thus neglecting to account for most aspects of external activity.

The model has been used in the analysis of rebound effects (increased consumption from cheaper energy resulting from efficiency savings), the UK Climate Change Levy, and the effects of establishing a marine energy industry in the UK.

UKENVI is able to provide a baseline forecast for Scottish energy demand. Compared to MDM-E3, it has the advantage that it will have a long-run forecast that can converge to equilibrium in the sense of equality between the supply and demand for factors of production in the economy. In addition, this model requires less detailed data as an input than MDM-E3, but still maintains a level of disaggregation.

The primary disadvantages of this model are that the short-run forecast may be less realistic than that produced by using MDM-E3, and that it neglects to factor in some important aspects of the economy, such as trade and the monetary sector, while making some rigid assumptions about the nature of the various markets.

Nevertheless, the model has the potential to produce a useful forecast for the purposes of the coming work.

Cyril Sweett (2007)

A Cost Review of the Code for Sustainable Homes


While not specifically an economic model, the Cyril Sweett analysis of the Code for Sustainable Homes provides an analysis of the technical and associated financial implications of achieving compliance with the different Code standards for energy and water. The Code itself sets a national standard for sustainable new homes and will provide the basis for future building regulations in relation to carbon emissions.

The analysis compares the additional costs associated with building a home to a certain level beyond a baseline, on a per m 2 basis. The analysis represents an estimate of the total costs to a contractor, including materials, plant and labour, preliminaries, overheads, contingencies, profit, and design fees. The analysis relates to the construction of the dwellings only and excludes many other costs that a developer is likely to face. The analysis focuses only on the construction costs in order to meet these energy, water and emissions targets and does not cover the corresponding savings for the households (as these are defined by the levels in the Code itself).

This analysis will be of most use in assessing the costs of construction of dwellings that meet particular energy, water and emissions standards. The analysis presented in this paper is a rigorous assessment of these costs and could be used to provide a beneficial foundation to aspects of the work undertaken in this project. Detailed information is provided in the report (and its update) on methodology and through this adaptations could be easily made to the work to suit the needs of the work in this project.

However, the approach embodied in this paper is not able to contribute to the analysis of the benefits to homeowners and the effects on energy demand.

Possibly some useful data on the cost of renewables.


Updated Energy Projections


The Department for Business, Enterprise and Regulatory Reform ( BERR) produces projections and analysis of energy use and CO 2 emissions in the UK. The work is based on knowledge of firm energy policy decisions, consistent with recent Budget announcements.

The figures are published regularly to reflect changes in fuel prices and other key assumptions on economic growth and inflation, which are exogenous in the model. The model itself provides forecasts of emissions from various sources and sectors, together with analysis of the effects of the ETS and projections of energy demand by user.

This analysis, whilst incorporating all Budget decisions on energy policy, does not provide forecasts for scenarios outside these measures.

Few details are released regarding the nature of the modelling besides the inputs and outputs. The information available in the public domain that could be of use is the various sets of assumptions for prices and the baseline projections of energy demand that are released periodically by BERR to elicit feedback from key stakeholders and inform their energy and emissions modelling.

Baseline assumptions on fuel prices and energy demand.

Cambridge Econometrics (2007)

REEIO (Regional Economy-Environment Input-Output model)


Developed for the REWARD (Regional and Welsh Appraisal of Resource Productivity & Development) project, this model analyses economic trends and policies on resources and the environment in England and Wales. The model itself is is based on a detailed model of each regional economy, based on the widely used Local Economy Forecasting Model ( LEFM).

The economy is disaggregated into 50 sectors, each of which makes transactions with each other sector. In addition, the labour market is shown in 6 types of employment and 25 types of occupation. The REEIO then links economic and employment changes with key environmental and resource pressures - covering waste, energy, air emissions and water impacts

Inputs required by the user include assumptions about national and regional economic and emissions forecasts. This model is comparable to MDM-E3 but on a smaller scale. Unlike MDM-E3, baseline data on emissions or economic growth must be provided, and then changes in policy can be assed in terms of changes to this baseline.

This model is likely to have limited use within the scope of the project. However, it could potentially be used to inform an assessment of the regional economic impacts in Scotland as a result of changes in the environmental characteristics of the housing stock.