Sustainable Energy for Historic Buildings

Sustainable Energy for Historic Buildings

Workshop Report

/ Transition
Stratford /

Sponsored by the Trustees of the C. A. Rookes Charitable Trust

Introduction

Saving energy will save money, as well as reducing greenhouse gas emissions. But energy efficiency works can be difficult for historic buildings, where legislation restricts the opportunities for both internal and external alterations. Specialists have been working on ideas, but it can be difficult for those responsible for historic buildings to find out how they can make practical changes to improve their energy efficiency and sustainability.

It was in response to this situation that Stratford-upon-Avon Town Council, The Stratford Society and Transition Stratford organised a workshop on sustainable energy for historic buildings on Tuesday 18th May 2010.

The workshop was particularly timely, given the publication by the Government at the end of March 2010 of Planning Policy Statement 5: Planning for the Historic Environment – the first revision of guidance in this area for over 15 years. Policy HE 1 "Heritage assets and climate change", makes clear that we need to look for opportunities to reduce carbon emissions and secure sustainable development when making decisions about historic buildings.

It was also appropriate that Stratford upon Avon should be one of the first places in Britain to take the initiative in seeing how its historic heritage can be made more sustainable. Heritage is integral to the appeal of Stratford to the millions who visit it each year. But while people appreciate Stratford as a historic town, Stratfordalso has to be forward looking. Climate change cares little for history, so we need to find ways in which our heritage can be preserved and adapted to the new demands of a low carbon future.

The workshop heard from expert speakers about some of the challenges and potential ways forward in seeking to make historic buildings more sustainable. Participants also had the opportunity to talk to local businesses which had experience of providing sustainable energy solutions for historic buildings. In a final question-and-answer session, the workshop sought to identify key issues and ideas to develop in the future.

This report summarises the speakers' presentations and the discussion in the final session. The workshop concluded with the suggestion that a follow-up meeting should be held to look at two specific ideas: developing understanding through case studies of local buildings and improving access to information through the internet.

Speakers' presentations

John O'Brien, Building Research Establishment (BRE)

John began by highlighting the many reasons for trying to make older buildings more energy efficient, including reducing CO2 emissions, cutting energy costs – and making them better places to live in.

John is closely involved in the Rethinking Housing Refurbishment projectin which BRE has been collaborating with a number of other organisations. This has been looking at ways to refurbish older buildings to make them more energy efficient. He reviewed a number of case studies forolder properties in different parts of the country. These projects are looking at the range of possible interventions for each building, working out which have the greatest impact on energy efficiency (increasing the building's SAP rating) – and which are the most cost effective.

An important issue that has arisen as a result of this research is the need to develop construction industry skills so that the most appropriate interventions can be carried out by local tradespeople: at present, too few know what to do (or how to do it properly).

Nick Molyneux, English Heritage

Nick highlighted the new Planning Policy Statement on the historic environment, which gives a starting point for any changes to make older buildings more energy efficient. He pointed out that there is a wide range of guidance available from English Heritage and similar organisations on specific techniques.

The most recent report from English Heritage, for example, looks at ways to improve the energy efficiency of sash windows. It suggests the best – and cheapest – first step is better draught proofing, using heavy curtains and shutters. This shows that it is not always necessary to look to new technologies to improve the energy efficiency of older homes. Many traditional techniques can be very effective – and are often better for older buildings: for example, by taking account of the way older buildings handle moisture. It also raises the question of skills in the construction sector: too few tradespeople know how to use these older techniques effectively.

Nick also argued that when we consider the amount of energy already used to put up a building – its embedded energy – it makes sense to look for ways to make existing buildings more energy efficient. Not only does it make no historic sense to get rid of older buildings and replace them with new, more energy efficient constructions – simply to do so would require enormous amounts of energy itself.

Nicole Solomon, Marches Energy Agency (MEA)

Nicole explained MEA's participation in the SECHURBA project (Sustainable Energy Communities in Historic URBan Areas) - a European initiative on sustainable energy for historic buildings. As part of its contribution to the SECHURBA project, MEA is undertaking a number of case studies of older buildings in Shrewsbury.These buildings have been surveyed and plans produced for reducing their use of energy by around 40 per cent using a range of different techniques. The aim is to use the case studies to prepare guidelines on the different approaches available and how they might be appropriate to different buildings.

MEA is also carrying out technical research into some of the materials and technologies that might be used for older or historic buildings. This includeslooking at the effectiveness of older building techniques and traditional materials as well as at the usefulness of new materials and technologies that have recently come on to the market. Again the aim is to provide guidance on what can be used and in what circumstances.

Tony Perks, Stratford-on-Avon District Council

Tony explained that as a planning authority, Stratford-on-AvonDC requires all development proposals to be sustainable, taking account of such issues as climate change, peak oil, energy costs and general consumption of resources. It is keen to encourage energy efficiency and energy conservation.

The Council will rely heavily on the new Planning Policy Statement when dealing with proposed changes for historic buildings. The main principle will be that changes are intelligent so that buildings can be passed on to future generations. But this also means recognising that some changes may have to be made to preserve that inheritance.

In practice, the Council will encourage energy efficiency in ways that balance energy concerns with historic character. It will also want to see interventions that do not damage the buildings and which (ideally) are reversible. Solid wall insulation is important, but can be a challenge; floor insulation may be easier to approve as it will often be invisible. For windows, simple changes such as heavier curtains may be more efficient, as well as more in keeping with historic character, than changes to fenestration.

Question and Answer Session

1. Energy efficient light bulbs – where is the technology now? Should you wait for new technological developments before replacing?

A. The technology is still developing, but a wide range of low energy bulbs is now available and it is important to replace old bulbs to save carbon and money.

1. There is a problem that there is no easily accessible energy survey for historic buildings.

1. This is a gap. The T-zero website has some information, but an additional problem is funding a survey, which by its nature could be expensive.

1. What do we know about the U-values of sash windows and how they can be improved?

1. Information on calculating U-values is available in the technical appendices to SAP guidance. But the recent English Heritage report on sash windows includes calculations – and shows how simple changes such as using heavy curtains can make measurable improvements to the U-values of a window.

1. Householders living in listed buildings can find it difficult to get information to help them make energy efficient choices.

1. Stratford-on-Avon District Council's website has some links from its pages on listed buildings. However, there is a need to pull together such information – perhaps Transition Stratford could take this on?

1. Is there a requirement to make older buildings more energy efficient?

1. There are many reasons for making all buildings more energy efficient, including climate change and rising fuel prices. These apply to all older buildings, not just those which are listed. Government initiatives such as energy performance certificates (EPCs) also encourage improvements in energy efficiency, and there are a variety of market-based incentives, mainly operated through the utility companies, to make improvements. However, no owners are forced to make improvements to the energy efficiency of a building.

1. One problem is that energy consumption is not yet important as a determinant of house prices.

1. This may change with rising energy costs. Another option might be for legislation to require improvements, but this is currently unlikely.

1. Does the construction industry have the skills to undertake appropriate energy efficiency works on older buildings?

1. There are several accreditation schemes which aim to raise the level of skills in the building industry: for example, an accreditation approach has already been introduced for installers of renewable energy technologies. However, in addition to specialist contractors, it will also be important to get traditional trades to take on and use new skills: greater use of traditional skills will be particularly useful for older buildings. There are currently a number of local training schemes, though these are perhaps not well enough known. However, one problem for historic buildings is that more than one skill or trade may be needed, so how do you organise the right combination of trades? Local authority building control can play a role, but this will probably be limited.

1. What are the economic options for older buildings?

1. This is a question of choosing the interventions which give the greatest saving of carbon for the least cost. The Rethinking Housing Refurbishment case studies are investigating this. At present it can be difficult for owners – or even intermediaries, such as architects – to gain access to sound information to help with such decisions. Research, such as that presented earlier in the workshop, will help improve this situation over time. Another thing to think about is behavioural change. Drawing curtains early to exclude draughts, or wearing thicker clothes, may help. Older buildings were not built for a cheap energy lifestyle, and it will probably not be appropriate to try to alter them to support one.

1. Is the planning and management of energy improvement projects a gap?

1. If you are planning to invest in changes to a building, it is important to get a sound and comprehensive review of the options and good advice on which approach might suit your situation. There may also be a need to co-ordinate a number of trades to make the best changes. And yes – at present a mass service of this sort is not available, though some big corporates, such as Marks & Spencer, are looking into the idea.

1. Do heat pumps have a role?

1. There may be scope for heat pumps in some circumstances. The use of ground source heat pumps may be limited by a building's location, as land is required to locate the pump. Air source heat pumps are another option. Some types of heat pump are still experimental and being tested by BRE.

Next Steps

Councillor Jenny Fradgley, the Mayor of Stratford, who had chaired the workshop, closed the workshop with a brief summary of some of the key points which had emerged. These included the need for better and more easily accessible information on technical options for historic buildings – and on the local businesses that might help owners take advantage of them. There is also clearly the question of ensuring that skills and knowledge are available locally so that work on historic buildings is carried out appropriately and to satisfactory standards.

A follow-up meeting would be organised to look at how these, and other issues raised during the workshop, might be addressed locally. Two specific ideas that the meeting might examine were developing a better understanding of issues through case studies of local buildings and improving access to information through the internet.

Resources

Further information about the Rethinking Housing Refurbishment project described by John O'Brien can be found at Case studies can be found on the Refurbishment Exemplars pages. The T-Zero website to which John referred is at

For advice and information from English Heritage see The sash windows report discussed by Nick Molyneux can be found under the Professional tab on the site: go to Research/Buildings/Energy Efficiency.

Information about the SECHURBA projects is at The case study and technical information covered by Nicole Solomons in her talk is not yet available.

Stratford-upon-Avon District Council publishes energy advice for historic buildings on its website at

For information on any follow up events, contact Transition Stratford on 01789 298503 or .