Key concepts in sustainable building - The Hempcrete Topic: Designing and Building with Hemp-lime - page 72

Before we go on to look in detail at building with hempcrete, it is worth briefly ex-
amining some key concepts and ideas that underlie the use of this construction ma-
terial. A good grasp of these ideas will help to inform sensible choices during the
design and construction phases of the build process.
Although most people who choose to use hempcrete today generally have a good under-
standing of these concepts, at present, in the UK at least, these vital factors are largely ig-
nored within the legislative and regulatory framework relating to the construction industry.
This means that there is also limited awareness of these ideas in wider society, which is an
impediment to the wider use of truly sustainable construction methods.
Zero-carbon buildings?
We live in a world increasingly aware of the need to minimize fossil-fuel use and limit the
emissions of carbon dioxide into the Earth's atmosphere. The construction industry in the
UK is responsible for an estimated 64 per cent of all UK carbon emissions. 1 This enormous
carbon bill comes both from the energy consumed in the construction of the built environ-
ment and from that used by the buildings' occupants during the lifetime of those buildings.
Clearly there is an urgent need to move to methods of building, and construction materials,
that are responsible for less CO 2 emissions in their manufacture and use. In addition, to re-
duce the energy consumed during a building's lifetime (most significantly in heating and,
in hot climates, cooling the building) we need to ensure that the construction materials and
designs are able to deliver energy-efficient buildings, which work passively to regulate in-
ternal temperatures and so need less fuel to heat or cool them. Third, since knocking down
inefficient buildings and building new, efficient ones in their place would use far more en-
ergy than it saves, we urgently need to upgrade the thermal performance of our existing
housing stock to bring it up to (or closer to) the current standards.