Planning the build - The Hempcrete Topic: Designing and Building with Hemp-lime - page 192

using wood-fibre insulation panels. Being in an exposed location close to the Atlantic coast
in north Cornwall, Bob and Tally have sensibly used a larch rain-screen cladding over the
hempcrete on the exposed walls (most of the house); on the south side, they used a breath-
able render. Bob's motto for the build was 'Low-tech - high performance', and this comes
out in the solidity and strength of the materials that surround us as we stand in the kit-
chen: oak posts and beams, solid black slate flooring, black slate windowsills, lime plasters
and thick hempcrete walls. The house, on a scorching July day, feels reassuringly cool and
comfortable, despite the fact that we are sitting next to the large south-facing windows and
the external doors are open, allowing a direct connection with the heat outside.
In the winter, heating is provided by a wood burner in the living room, the flue of which
passes through the master bedroom on its way to the roof, allowing the passive transfer of
heat into the bedroom. There is a solar domestic hot water system, and an air-source heat
pump to supply underfloor heating, but Bob and Tally find that they hardly ever need to
use it. Even in very cold winters, the heat from the wood burner alone is more than enough
to maintain a comfortable temperature throughout the house “at least 90 per cent of the
time - and to be honest a lot of the time we probably have it on for the atmosphere rather
than heating. The only time we turn the heating on is when we've got guests in the spare
bedroom and we feel we should heat up the 'north wing' for them,” says Bob.
Agan Chy.