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, Stratford also 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 project in 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 for older 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 includes looking
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-Avon DC 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
Q. 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.
Q. There is a problem that there is no easily accessible energy survey for historic
buildings.
A. 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.
Q. What do we know about the U-values of sash windows and how they can be
improved?
A. 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.
Q. Householders living in listed buildings can find it difficult to get information to
help them make energy efficient choices.
A. 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?
Q. Is there a requirement to make older buildings more energy efficient?
A. 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.
Q. One problem is that energy consumption is not yet important as a determinant
of house prices.
A. This may change with rising energy costs. Another option might be for
legislation to require improvements, but this is currently unlikely.
Q. Does the construction industry have the skills to undertake appropriate
energy efficiency works on older buildings?
A. 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.
Q. What are the economic options for older buildings?
A. 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.
Q. Is the planning and management of energy improvement projects a gap?
A. 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.
Q. Do heat pumps have a role?
A. 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 www.rethinkinghousingrefurbishment.co.uk. Case
studies can be found on the Refurbishment Exemplars pages. The T-Zero website to
which John referred is at www.tzero.org.uk.
For advice and information from English Heritage see www.english-heritage.org.uk.
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 www.sechurba.eu. 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 www.stratford.gov.uk/planning/planning-3213.cfm.
For information on any follow up events, contact Transition Stratford on 01789
298503 or admin@transitionstratford.com.