Memorandum submitted by the Institute
of Historic Building Conservation
The Institute of Historic Building Conservation
(IHBC) is the professional body of the United Kingdom representing
conservation specialists and historic environment practitioners
in the public and private sectors. The Institute exists to establish
the highest standards of conservation practice, to support the
effective protection and enhancement of the historic environment,
and to promote heritage-led regeneration and access to the historic
environment for all.
The Institute welcomes the opportunity to submit
a memorandum to this Inquiry.
The Institute's interest in the Inquiry arises
because an estimated 25% of the housing stock consists of historic
buildings and those of similar traditional construction. Broadly
speaking, this is constituted by nearly all pre-1919 stock and
some post-1919 stock. The Institute is also interested because
a substantial proportion of post-1919 housing stock is in conservation
areas and other areas of visual quality which it is desirable
to preserve and enhance.
The Institute welcomes the Government's drive
to reduce greenhouse gas emissions and switch to alternative energy
sources. We welcome the approach that pays close attention to
improving the performance of existing buildings and recognize
that historic buildings do have a part to play in achieving the
overall aim.
However, the Institute is concerned that much
of the drive for energy efficiency is based on new technologies
and their use in the construction of new housing. This largely
ignores traditional and vernacular approaches many of which have
merit, particularly when the future of traditionally built stock
is being considered. Examples of these approaches are set out
in Appendix A to this memorandum.
The Institute has four broad areas of concern:
— The desirability of a whole life-cycle
approach to energy use in existing buildings.
— The need for well-structured independent
guidance on energy efficiency in the existing housing stock.
— The importance of improving the energy
efficiency of historic property in ways that do not undermine
its integrity.
— The importance of quality of place
in improving and maintaining the value of existing housing.
WHOLE LIFE-CYCLE
APPROACH TO
ENERGY USE
When dealing with existing buildings, the Institute
believes it is important to consider the whole life-span of the
building in energy terms and not just its energy performance in
use as the Building Regulations do. With new construction the
energy requirement in construction may vary from project to project
but there can be no offset for the embodied energy of existing
fabric. With existing buildings account can, and should, be taken
of this.
The construction and demolition industries account
for about a quarter of all waste produced. The Housing Market
Renewal Pathfinders have caused the demolition of large numbers
of dwellings many of which, it has been shown by Urban Splash
and others, could have been remodelled and re-used. Many building
materials have high energy inputs in their manufacture including
bricks and especially cement. Yet it is estimated that 70% of
all brick manufacture is merely replacement of stock lost through
demolition. It is important, therefore, to prolong the lifespan
of buildings and thus avoid the manufacture of new materials with
its energy implications wherever possible.
Where buildings do have to be demolished, re-use
of materials should be promoted wherever possible. It is known
that sometimes recycled materials are not used because there is
no guarantee of their long-term performance. Government guidance
on how to evaluate life-expectancy of recycled materials would
be useful. There is a strong argument for demolition to be brought
within full planning control. This would allow approval subject
to conditions which might regulate the destiny of salvageable
components and materials and thus reduce energy use overall.
The Institute would like to see a shift in the
balance of the Government's approach to energy efficiency towards:
— The use of whole-life energy audit
of houses as an assessment of their energy efficiency.
— Where houses are proposed to be demolished
and replaced, full whole-life energy audits of both refurbishment
and replacement informing the decision.
— Better recognition of traditional
building techniques and materials that promote recycling and recyclability
of materials.
NEED FOR
GOOD INDEPENDENT
GUIDANCE ON
ENERGY EFFICIENCY
IMPROVEMENT
Improving the energy performance of existing
buildings needs to be done in ways that are complementary to the
nature of the building and its original construction. Traditionally
constructed buildings do not perform in the same way that modern
buildings do. Modernisation techniques based on air-tightness
and ill-considered positioning of vapour barriers are often incompatible
with property built traditionally in which the ability of the
fabric to move and breathe is vital for its long-term safety and
future.
It is important, therefore, that in any campaign
to improve the energy efficiency of existing dwellings, proper
independent advice is available. This needs to ensure that property
owners do not find that the promised long-term financial benefits
of thermal improvements (there are rarely any short-term benefits)
are not overshadowed by disbenefits caused by deterioration to
the fabric of their home.
uPVC windows are an example of a building component
frequently installed in the interests of energy efficiency without
consideration to whole-life energy implications. The decision
to install them is usually taken on the basis of estimates of
heat loss reductions (the information supplied by the window's
salesman). The following aspects are often ignored:
— The energy used in manufacture (from
a fossil fuel source).
— The energy used in disposal (uPVC
has a much shorter life-span than well-maintained, good quality
timber).
— The polluting effects of disposal.
— If the house is of traditional (pre-1919)
construction, the possible adverse effects on its fabric and the
costs involved in remediating them or in a shorter lifespan for
the house.
— The effect on the value of the house
or its location by the alteration of its visual appearance.
The Institute believes there needs to be much
better information on the costs and benefits of energy improvements
for householders. The relationships between the costs and benefits,
in both financial and energy terms are complex. These are well
known in the case of some simple techniques (draught proofing
and loft insulation, for instance) but far less so in others,
particularly those involving higher costs (double glazing, wall
insulation, microgeneration).
It is to be hoped that the building industry
might be engaged in the process of disseminating best practice.
This should involve a more holistic approach that placed emphasis
on the interests of the property rather than the supposed benefits
of individual products according to their manufacturers and suppliers.
MAINTAINING THE
INTEGRITY OF
HISTORIC BUILDINGS
The listed building regime is shortly to be
replaced with a unified register of historic assets. It is important
that any changes to regulation or advice on the energy efficiency
of housing take this into account. There is a strong argument
for extending special consideration to all houses of traditional
construction (say all pre-1919 houses) to ensure that new energy
efficiency initiatives do not undermine their fabric and longevity.
Historic buildings are protected because of
their historical and cultural value. While improving the energy
efficiency of listed buildings is a laudable goal which the Institute
supports, the techniques to be used must be compatible with the
need to preserve the historic character and appearance of the
building. Energy efficiencies can be incorporated into listed
buildings without harm, but many modern techniques can cause serious
harm to the fabric of the building or otherwise adversely affect
its character or appearance.
So it is vitally important that listed buildings
retain their exemption from the full rigours of Part L of the
Building Regulations with possible extension of this to pre-1919
houses. In recent consultations about extensions to permitted
development rights, we argued that the setting of listed buildings
was an important aspect which had been missed when the proposals
had been drafted. There is a danger that proposals for energy
efficient improvements (that would clearly benefit the building
for which they were proposed) might be seriously detrimental to
the character and appearance of a nearby listed building. In this
context wind turbines and external cladding spring immediately
to mind.
Historic buildings were usually built in a manner
we would call sustainable today: local materials, low energy inputs
and reusable and recyclable components. In particular, lime was
(and is) a particularly green material because it fixes CO2
whereas cement production causes 3% of all greenhouse gas emissions.
Returning to environmentally friendly methods of construction
should be a complementary part of the process to the primary aim
of reducing buildings' energy in use for existing buildings (including
historic ones) and new construction alike.
BS 1793:1998 Guide to the principles of the
conservation of historic buildings provides a good starting
point for the development of best practice on energy efficiency
for historic buildings, but will need further development and
a significant price reduction to bring it into more widespread
use.
MAINTAINING THE
QUALITY OF
PLACES
Housing stock makes up a substantial percentage
of the nation's wealth. It is important that this should continue
to be valued and invested in. Some of the country's most treasured
areas are designated as conservation areas. It is important that
the visual quality of conservation areas is not impaired by insensitive
proposals to alter existing dwellings. This is explicitly accepted
in the Government's drive to improve the quality of places through
improved design.
In recent years there have been many examples
of ill-considered alterations to houses that have undermined the
historic and visual qualities of conservation areas—loft
conversions, external cladding, plastic windows etc. The Institute
would wish to see Government policy and guidance on energy efficiency
developed in such a way that does not contribute to degrading
the visual appearance of historic places. Proposals for energy
efficiency should not just take into account the benefits for
the individual building but also the wider environmental impacts.
We would be grateful if these comments could
be taken into account. The Institute would be happy to give more
detailed evidence on any aspect raised in this memorandum.
APPENDIX A
The IHBC and its members work towards the sustainable
reuse of existing buildings by:
— Promoting the reuse of buildings
rather than demolition and redevelopment—the manufacture
of 30 bricks uses the equivalent of one gallon of petrol. 90,000
houses—the equivalent of a town the size of Derby—are
demolished annually.
— Promoting the use of local craftspeople
who contribute to the viability of their local community rather
than supporting mass production and extensive carriage distances
for products and materials.
— Supporting local business premises
and community buildings through grant aid.
— Promoting the use of natural long
lasting materials which are produced without generating noxious
side effects.
— Promoting the use of sustainable
timber and locally available materials.
— Keeping our activities to levels
that do not permanently damage the environment by taking a long
term view.
— Ensuring that decisions about the
historic environment are made on the basis of the best possible
information.
— Developing projects that incorporate
these policies, including promoting best practice to developers,
home owners and the wider public.
— Promoting designs for new buildings
in historic areas which exploits the natural advantages of the
site to maximise heat gain and minimise heat loss. This includes
main windows on sunny aspects with cat slide roofs and few or
small windows on cold sides, shelter from cold north easterlies
provided by walls, hedges, trees along boundaries etc.
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