Planning the build - The Hempcrete Topic: Designing and Building with Hemp-lime - page 185

the significant benefits to the health of the building and its occupants
the fact that conventional construction materials generally have a very high embodied
energy, whereas hempcrete acts as a 'carbon sink', locking CO 2 away.
For those undertaking the build themselves or providing some of the labour, costs can be
reduced still further, but this does need to be planned for properly in the build, to ensure
enough labour will be available when needed (see opposite).
Design
In practice, many of those who have creative control over the design of their building will
feel more comfortable working closely with a professional architect than taking on the task
of designing it themselves. Bear in mind that, at the time of writing, it is still rare to find
architects who have direct experience of specifying hempcrete in building design, although
they should know where to access more information about it, especially if they specialize
in designing sustainable buildings.
As hempcrete is a relatively new material, it's important for anyone considering using it
to understand its key properties, the structural limitations on how it can be used, and how
these factors interact with each other in the design of a hempcrete building, before propos-
ing construction details. This is something that client and building designer need to discuss
at an early stage, to ensure that everyone involved in the design process understands the
material, and that if they don't, that specialist consultants will be involved at an early stage
of the design process, as mistakes can be expensive to correct at a later stage of the build.
It is to be hoped that anyone designing and building with natural materials, hempcrete in-
cluded, will take a holistic view of how the building will work. This makes far more sense
than, for example, just putting in a hempcrete 'feature' within a building made up of dif-
ferent materials, including conventional synthetic materials that do not complement hemp-
crete at all. Switching over from natural to synthetic materials within the same building for
the sake of aesthetics not only risks creating a disjointed feel but also often fails to make
use of the most useful features of hempcrete and other natural building materials, which
tend to work best as a whole building system.
For example, hempcrete, as discussed in previous chapters, has the potential to offer great
benefits in terms of insulation, airtightness and reduction of cold bridging, owing to its
cast-in-situ application method. Since it can be used for floor slabs and roof insulation