Heritage Retrofit

5 / 54

BCD SPECIAL REPORT ON HERITAGE RETROFIT FIRST ANNUAL EDITION 5
a maximum of 25 years? A particular
problem arises with the glass, and
this author has yet to be convinced
that the building industry is able to
resolve the inherently limited lifespan
of sealed double- and triple-glazing.
Double windows and secondary
glazing, which tests have demonstrated
to have thermal characteristics at least as
good as if not better than sealed glazing
units, have been the norm across much
of continental Europe for centuries.
They often offer a viable alternative that
accords with the heritage principle of
minimum intervention, is not subject to
failure of the glazing technology, and is
highly durable.
COORDINATED, COST-EFFECTIVE
ACTION
An increasingly invoked truism is that
the most sustainable building is the
one that has already been built. Lack of
holistic understanding and simplistic
energy certification systems serve to
undervalue the energy performance of our
existing building stock, especially older,
traditionally constructed buildings.
The retrofitting of our built heritage
requires a methodical approach to
assessing and respecting its heritage
significance in whole and in its discrete
parts. Europe’s building stock has a
historical and projected longevity that
constitutes a major contribution to the
reduction of global carbon emissions:
through the environmental capital that
has already been invested in it; and
through the potential for significantly
reducing or eliminating the occupancy
emissions by a combination of energy
efficiency retrofitting and conversion to
renewable energy sources.
To meet global emissions reduction
targets, we need to mainstream retrofit
measures and systems to satisfy
complementary objectives. Central to
this are principles that have hitherto
been most closely associated with the
heritage sector, including minimum
intervention and minimal ecological
impact. Common ownership of these
across the whole retrofit sector will
enable coordinated, cost-effective action
at the scale that is required to counter
the predicted impacts of anthropological
global warming.
Further Information
EFFESUS Consortium, Energy Efficiency
in European Historic Urban Districts:
A Practical Guidance , 2016
)
European Union, Toledo Declaration on Urban
Development, 2010
)
C Hermann and D Rodwell, ‘Heritage
Significance Assessments to Evaluate
Retrofit Impacts’, in B Szmygin (ed),
How to Assess Built Heritage?, Heritage for
Future, Florence-Lublin, 2015
C Hermann and D Rodwell, ‘Retrofit
Measures for Historic Buildings
and Cities’, in Context 142, 2015
J Hulme and S Doran, In-situ Measurements
of Wall U-values in English Housing, BRE,
Watford, 2014
)
D Rodwell, ‘Climate Change and
Energy Initiatives in Scotland’, in
Context 115, 2010
J Wallsgrove, ‘The Justice Estate’s Energy Use’,
in Context 103, 2008
C Wood, ‘Making Historic Buildings Even
More Sustainable’, in Context 111, 2009
World Commission on Environment and
Development, Our Common Future
(aka The Brundtland Report),
OUP, Oxford, 1987
The World Conservation Union, United
Nations Environment Programme
and World Wide Fund for Nature,
Caring for the Earth: A Strategy
for Sustainable Living, 1991
DENNIS RODWELL, architect-planner,
is an international consultant in
cultural heritage and sustainable urban
development (www.dennisrodwell.
). Previously a principal in
private practice and a heritage at
risk developer, he has also served in
local government posts as architect,
conservation officer, urban designer,
principal planner and project manager.
He was a partner in the EFFESUS
research project described in this article.
Sibiu, Romania: historic double windows, typical of those found throughout
Central and Eastern Europe
Stirling Castle, Scotland: crafted secondary glazing and shutters have been
installed as part of the restoration works in the royal apartments.