Heritage Retrofit

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BCD SPECIAL REPORT ON HERITAGE RETROFIT FIRST ANNUAL EDITION 17
EPCs at CLOVELLY
JONATHAN TAYLOR
ENERGY PERFORMANCE
Certificates (EPCs) are needed
whenever a property is built, sold
or rented. The EPC indicates the energy
efficiency of the property as estimated
by the standard assessment procedure
(SAP). The higher the score the lower
the running costs are likely to be, with
100 representing zero energy cost. EPC
band A (most efficient) corresponds to
a SAP score of 92–100, while band G
(least efficient) corresponds to a score
of less than 20 (see figure on page 15).
Listed buildings are generally exempt
from the requirement, but often owners
choose to have their properties assessed
in any case. In Clovelly, a picturesque
village on the North Devon coast, most
of the buildings are rented to people
who live and work in the region. John
Rous, who owns and manages the estate,
considers the EPC rating as a necessity
in a competitive market for attracting
tenants, whether or not the building is
listed. With the help of Mukti Mitchell
of the CosyHome Company, the estate
has an ongoing retrofit programme to
improve the EPC rating of their housing
stock to at least band E, which is the
minimum level set by the government
for letting residential properties from
April 2018. Measures are chosen to give
the greatest economic return, taking
into account not only improvements
in EPC rating and fuel efficiency, but
also any risk of damage to the fabric in
the long term from the alterations.
There is growing recognition that
some measures encouraged by the SAP
system are inappropriate for traditional
fabric, and the estate’s consultant was
particularly concerned by the risks
posed by solid wall insulation. Key areas
for improvements therefore include roof
insulation, draught exclusion, secondary
glazing and high-specification night
storage heaters which store more heat
and control its release more effectively.
EPC point gains are carefully simulated
by an experienced EPC assessor
and used as a guide for the work to
each property. The table opposite
summarises the likely benefits from
each measure.
Loft spaces which were readily
accessible already contain some
insulation, but many of the houses have
rooms within the roof space with sloping
ceilings and dormer windows. These
are more difficult to improve, requiring
insulation between and below rafters and
studs, before relining and re-plastering.
In terms of keeping the heat in, roof
insulation and the draught-proofing of
windows have the greatest impact, and
for the attic bedrooms with uninsulated
dormers, the cost per SAP is very good,
despite its high cost. However, for gaining
the most SAP points, the most cost-
effective measure is the introduction of
night storage heaters to replace a variety
of older heating appliances. Although
electricity generation and distribution has
a relatively high carbon footprint, the SAP
system encourages the use of modern night
storage heaters because they use energy
from the grid when demand is least.
THE AUTHOR This case study was prepared
by editor Jonathan Taylor with the help of
Mukti Mitchell, CosyHome Company
) and
John Rous, Clovelly Estate Company Ltd
.
Number
of houses
affected
Average per house
Cost per
SAP point
Cost of work SAP point
gains
Night storage radiators 23 £4,174 23.0 £180
Room in roof insulation 29 £4,717 15.0 £318
Loft top-up insulation 15 £613 1.3 £460
Secondary glazing 39 £3,484 4.2 £829
Draft proofing doors &
windows 29 £1,362 1.6 £859
Data reproduced by kind permission of Clovelly Estate
The main street of Clovelly, Devon (Photo: Jonathan Taylor)