Select Committee on Communities and Local Government Committee Written Evidence


Memorandum submitted by English Heritage

INTRODUCTION

  English Heritage welcomes the decision of the Communities and Local Government (CLG) Committee to examine the contribution which the existing housing stock makes to UK carbon emissions. This is an opportunity to demonstrate that the stock of existing traditional buildings can be adapted sympathetically to contribute to the overall reduction of carbon emissions from England's housing stock. English Heritage is keen to use our practical knowledge and expertise of how older housing behaves to help people understand how to make adaptations which respond to climate change while maintaining the character of historic buildings.

  The briefing on the inquiry and the call for evidence itself acknowledges that the UK's attempt to reduce carbon emissions will present specific challenges for the management of the nation's older housing stock and recognises the challenge of retaining historic interest. English Heritage strongly supports the principle of improved energy efficiency in buildings, but we are concerned that poorly considered alterations could do irreparable harm to England's finite resource of traditional building materials and structures, and in some cases impair rather than improve their energy efficiency. Therefore we are keen to ensure that owners, landlords, specifiers, building control officers and domestic energy assessors better understand how traditional buildings behave, and how adaptations might best be chosen to truly improve their energy performance.

GENERAL POINTS

  1.  The historic environment is our most accessible cultural resource and has a powerful influence on peoples' sense of identity and civic pride. It contributes significantly to the character and sense of place of rural and urban communities and lies at the heart of sustainable growth and place-making. English Heritage is the Government's statutory adviser on all matters relating to the historic environment in England. We are a non-departmental public body established under the National Heritage Act 1983 to help protect England's historic environment and promote awareness, understanding and enjoyment of it.

  2.  Britain's stock of traditional housing account for approximately a quarter of all homes in the UK and forms part of the character and distinctiveness of our country. There is therefore a considerable risk from inappropriate or poorly executed adaptations to improve energy-efficiency. In addition to the approximately 370,000 listed structures in England, there are over a million unlisted buildings in England's 9,374 conservation areas. Our concerns are also relevant to all buildings constructed using traditional materials and techniques, even those that are not designated in any way. This means not only the 4.7 million homes built prior to 1919, before the use of modern impermeable materials became widespread (English House Condition Survey, 2005), but many later buildings, particularly those constructed between the wars (according to the English House Condition Survey, some 3.8 million buildings).

  3.  To help people understand the impact of climate change on older buildings, and how they can be adapted safely and effectively English Heritage is developing a website for home-owners, Climate Change and Your Home. Real savings can be derived from benign, relatively low-impact interventions, such as low-energy light-bulbs, condensing boilers, fitting energy switches on heating appliances, and improvements in the efficiency of electrical goods. English Heritage is also preparing extensive guidance on how best to apply Part L of the Building Regulations to traditionally constructed buildings.

  4.  In order to further develop guidance on best practice in improving traditional buildings we need better data. Techniques for measuring the energy performance of buildings are still in development, and must take account of the many different ways a building can be constructed and the many ways it is used by the people who live in it. For example with milder winters likely, is insulation the best approach to long-term planning for climate change? Insulation could result in homes overheating in the summer months, perhaps driving up the demand for air conditioning, and hence increasing rather than decreasing the total energy being consumed. Stopping heat loss by sealing chimneys and double-glazing all windows often leads to the occupants throwing open the windows for fresh air—losing much more heat than the leakage through the original windows ever did. Asking people to live in a hermetically sealed home, which maintains a steady internal temperature throughout the year, is probably unrealistic, and may well prove harmful to health.

  5.  In 2008 English Heritage will be embarking on a long-term study to develop measurement methodologies, and to use them to monitor a number of Victorian terrace buildings before and after energy-saving improvements have been made. From this we and our partners hope to develop robust new approaches to ensuring that the existing housing stock is as energy efficient as possible, and we anticipate that the information we gain will also be of use for designing efficient new homes. It is worth noting that traditional materials and structures were developed to be effective in a world where energy was extremely expensive, and that they may contain positive lessons on efficiency. For example, solid-wall construction was common, and this is now being recommended again for eco-friendly housing (Beating the Heat, keeping UK buildings cool in a warming climate, 2005).

  6.  The Committee's investigation into existing housing and climate change, is an important and timely initiative, and we welcome the opportunity to challenge some of the presumptions and establish a clearer evidence base for future policy. For example, Energy Performance Certificates are suggested as a suitable tool for comparing the energy consumption in different types of dwelling, but the methodology used by the Reduced Data Standard Assessment Procedure (RDSAP) calculator was not designed to deal with single houses, let alone houses built with thick solid walls and permeable materials. English Heritage has therefore developed guidance for Domestic Energy Assessors and home-owners, which advises that any recommendations generated by RDSAP should be applied with great caution (English Heritage guidance on Home Information Packs, specifically Understanding SAP Ratings for Historic and Traditional Homes, which can be downloaded from www.english-heritage.org.uk/homeinformationpacks).

  7.  In summary English Heritage fully supports a government-led initiative to look at the impact of the UK domestic housing sector on energy use, but recommends that it look more stringently at the underlying issues, for example:

    —  How can we measure the energy use of domestic buildings?

    —  How is energy used in domestic buildings? How does this vary in different types of building?

    —  What makes a house energy-efficient?

    —  How do we take whole-life costs into account?

    —  Are there lessons to be learnt from traditional building techniques and structures?

    —  How does the way a house is being used affect its energy efficiency? Are there ways of improving wasteful usage, without having a detrimental effect on the quality of people's lives?

    —  How is energy use in UK homes likely to alter in response to climate change? For example, will heating decrease but air conditioning become more common? Will the emphasis on more insulation today generate an increasing demand for more cooling?

ENGLISH HERITAGE'S RESPONSE TO SPECIFIC QUESTIONS RAISED IN THE CALL FOR EVIDENCE

The significance of existing housing compared to new build, and the different levels of performance each display

  Although there have been some very significant advances made within the construction sector in improving the thermal performance of new materials, English Heritage has not yet seen any compelling evidence to suggest that traditionally constructed homes perform worse than recently built homes. Historic building materials are often more durable than their modern replacements and more cost-effective in energy terms. For example, although properly maintained softwood window frames have an almost indefinite lifespan, PVCu windows are usually guaranteed for no more than 10 to 15 years. At current energy prices, this is far less than the time needed to repay any energy savings.

  Policy responses must be based on clear evidence. It is imperative to collect accurate data on the existing energy performance of various types of home together with the changes in performance delivered by appropriate improvement interventions. To this end we are currently developing a major research project to look at the overall energy efficiency of traditional homes. Building on work by others we need to evaluate, for example, how effective energy saving retrofitting can be accommodated across a wide range of construction types without compromising either the character or the long term material integrity of the building. Recent work by the Ministry of Justice for instance has suggested that their pre 1900 buildings are the most energy efficient per square metre and that such buildings should be prioritised for retention within their property portfolio (Ministry of Justice, 2007 Age Energy Research, A study of the energy usage of buildings relative to their age). It is essential that everyone with an interest in this area works closely to identify and share best practice. We therefore intend to discuss our proposed research in more detail with Government and construction industry leaders, to agree parameters for this and similar research, so that together we can begin to generate meaningful, comparative data.

  The existing housing stock may also have a role in reducing some climate change effects. For example, period homes in urban areas often have gardens both front and back, and it is already well appreciated that these play an important role not just in making our urban areas attractive places to live (see English Heritage, 2007, Suburbs and the historic environment), but in enhancing bio-diversity, allowing for exercise, recreation, and even food production. Now evidence is increasingly showing that they also play an important role in helping to temper rising urban temperatures and flash flooding (see for example the ASSCUE project, Royal Horticultural Society Front Gardens. Are we parking on our gardens? (2005) and Royal Horticultural Society Water in the garden. Are we draining our water supplies? How can gardeners save water? (2007)).

  There is a strong public wish to protect such homes, which offer generous internal and external space (see Greater London Authority, 2006: Housing Space Standards). Again, traditional structures may have useful lessons for new buildings.

The respective role of residents, homeowners, landlords, local government, central government and the energy industry in promoting and delivering greater energy efficiency

  As the government's advisor on the historic environment, English Heritage has developed a wide knowledge of how traditionally constructed buildings actually behave, and we are keen to use this knowledge to assist both government agencies and the general public.

  We are currently preparing extensive advice on energy efficiency and climate change effects on the traditionally constructed housing stock and intend to work with the Local Government Association's Climate Change Commission to promote best practice. Collaboration with DCMS, CLG and DEFRA should help to identify ways of communicating these and other important messages through all our websites, communication material, advice and guidance, and conferences.

Energy Performance Certificates

  We have already released draft guidance on EPCs and the related HIPs process (copies attached with this submission), and have also commissioned a qualified Domestic Energy Assessor (DEA) to survey a range of traditional dwellings using the standard techniques. Thus far seven buildings have been surveyed, and the results have confirmed our reservations.

  For example, the calculation for a 19th century two-up two-down terrace house, brick with original sash windows predicted an annual energy consumption of 448kWh/m2, and suggested improvements which would bring this down to 307 KWh/m2. Actual bills (confirmed with the supplier) showed power usage to be 223 KWh/m2: in other words the actual energy use was much less than that predicted for the house post-improvement. We therefore recommend that owners supplement the EPC with utility bills which show the actual energy consumed. We are discussing with CLG the possibility of a direct link from every EPC to our climate change website to ensure that easy free access to advice is made as straightforward as possible for homeowners.

Government efforts to reduce carbon emissions from existing housing stock whether in private or public ownership and other related programmes including Decent Homes

  English Heritage is concerned that Government targets to improve the energy efficiency of all dwellings may lead to inappropriate, damaging and potentially counter-productive building work to traditionally constructed homes. We would like to see a more targeted approach to improving domestic energy efficiency which draws attention to the differences between modern and older construction materials and methods. Our main concerns are not simply historic or aesthetic, but equally a desire to ensure that the performance of traditionally constructed buildings is not compromised by an imperfect understanding of how they work.

  The fundamental difference between modern and traditional construction is that modern buildings use impervious materials such as cement and plastic cladding to keep moisture out, whilst traditional buildings were built using thick permeable materials such as solid brick and stone masonry, timber and lime plasters, which can absorb excess moisture and release it slowly by evaporation. Modern building practice depends on perfect maintenance, because any leak will let water in but prevent it from escaping. The so-called "breathable" materials and structures, by contrast, are affected very little by localised damage, and are able to buffer large quantities of moisture—(timber roof beams of a typical house, for example, can absorb large quantities of water over time with minimal increase in their moisture content), keeping the internal humidity of an occupied building pleasantly stable, at no cost to the fabric. This is no accident: traditional materials and construction techniques were developed by a process of trial and error lasting several thousand years. Retro-fitting traditional buildings with modern materials usually dramatically alters the way the building is working, and all too often results in damp walls: not just giving a conduit for heat loss from the building, but also causing serious damage to the fabric.

The technologies available to reduce emissions and the Government's role in facilitating relevant further technological development

  There are many innovative developments taking place. Given the extent of the traditional housing stock, we would welcome more Government support in exploring the potential to adapt some of these existing technologies to traditional construction. We are also keen to ensure that traditional materials and methods are reassessed for use in new build. For example, solid stone masonry is currently almost unknown (most stonework is cladding), but it gives excellent thermal protection in both low and high temperatures. Although the initial costs are significant, stone-masonry buildings are very long-lived and require very little maintenance, so the whole-life costs may be very low. English Heritage is to host a conference at the end of January 2008 that will help explore some of these issues.

  English Heritage is also developing guidance for home-owners on how investment in micro-renewable energy-generation technologies can achieve value for money and be implemented without damaging the appearance, significance or performance of older buildings. (English Heritage guidance note: Micro Wind Generation and Traditional Buildings 2007)

  Real savings can be derived from benign, relatively low-impact interventions, such as low-energy light-bulbs, condensing boilers, fitting energy switches on heating appliances, and improvements in the efficiency of electrical goods. Using humidistat controls rather than thermostats on heating can not only reduce the demand for energy, but minimise the adverse effects on the building fabric of fluctuating temperatures and humidities.

The costs associated with reducing carbon emissions from existing housing, who should meet those costs and particularly, in respect of low-income households, interaction between carbon emission reductions and the Government's ambitions to reduce poverty.

  No comment.

The specific challenges which may arise in relation to housing of special architectural or historical interest

  Traditionally constructed buildings make up a substantial percentage of homes in the UK, and are likely to do so for the foreseeable future. According to the recent Housing Green Paper Homes for the Future: More affordable, more sustainable (CLG, 2007) the Government has calculated that by 2050 buildings now in existence will account for two-thirds of homes. Given the current rate of replacement of UK housing stock—around 1% per year—we will have to live with our existing buildings for some time yet. We cannot afford not to take proper care of our existing housing stock. It is in our interests to ensure that existing buildings are well managed and maintained, and that any recommended changes are based on a clear understanding of the overall effect they will have on the building's longevity as well as its efficiency.

  We all recognise the part that each of us must play in reducing carbon emissions. Maximising energy efficiency is a desirable objective for the environment, for the economy, and for residents. The Code for Sustainable Homes is a very positive step forward. However, English Heritage is concerned that a massive programme of standardised improvements may not be effective and prove to be carbon-costly. We believe that without a better understanding of how traditionally constructed buildings currently perform, combined with more reliable ways of measuring this performance, unnecessary, inappropriate and potentially damaging improvements will be specified on the assumption of inefficiency. We are particularly concerned that a drive by Government to improve traditional homes by adding wall and even roof insulation en masse could prove counter-productive, not only environmentally but also financially. As well as the high risk of damp and decay (leading to costly repair works, and causing the building to lose heat), the consumption of additional resources, including the carbon cost of manufacture and transportation of the insulation materials, must be taken into account. Building waste accounts for 24% of the total waste in the UK, with the Government's Performance and Innovation Unit report, Resource Productivity, noting that "energy is consumed in the production of construction materials such as bricks, cement and metals and in their distribution... Over 90% of non-energy minerals extracted in Great Britain are used to supply the construction industry with materials... yet each year some 70 million tonnes of construction and demolition materials and soil end up as waste." (Performance and Innovation Unit, 2000). How do the costs compare to the benefits to be gained by insulation? If careful, resourceful consolidation of existing fabric can achieve good thermal efficiency, to demand extra insulation on solid walls 40 cm or so thick would be a costly mistake.





 
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