Restoration and retrofit - The Hempcrete Topic: Designing and Building with Hemp-lime - page 456

Hempcrete also fits against old timber frames much more
snugly than board insulation does.
Key concepts in the retrofit of heritage buildings
It is not our intention to set out here comprehensive instructions for the use of hempcrete
in heritage properties. Nor would this be possible, or desirable, since in the sensitive repair
of or improvements to our architectural heritage every building should be treated on an in-
dividual basis, with a bespoke solution designed to provide the maximum insulation while
remaining sympathetic to the specific needs of the building - and within the parameters set
out by building control or, in the case of listed buildings, by the responsible body as part of
the listed building consent. English Heritage has produced a free pamphlet to help owners
of listed buildings understand the issues around improving energy efficiency without det-
riment to the building's character or existing fabric. 2
About 50 per cent of our work at Hemp-Lime-Construct is on heritage properties, and
while we have developed techniques that can often be reproduced in a number of situ-
ations, we find that to some extent each heritage job we undertake becomes a bespoke
design-and-build project. The way that the hempcrete is applied in heritage buildings has
to be adapted to work with the original building design and materials, as well as to meet
the requirements of the client and the conservation officer.
English Heritage are generally supportive of the use of hempcrete within historic buildings,
and it is one of the few materials they recommend for the upgrading of insulation in these