Hemp in construction - The Hempcrete Topic: Designing and Building with Hemp-lime - page 19

At the time of writing, hempcrete has been used in building for around 30 years - since its
'invention' in the 1980s. The use of hempcrete has gradually spread, first across Europe
and more recently around the world, and the number of people using it, both in new build
and in the repair of older buildings, continues to grow.
In the UK a great many buildings, both commercial and residential, have now been built
with hempcrete. A notable upsurge in the commercial use of hempcrete came with the Re-
newable House Programme, funded by the UK government between 2007 and 2010. Under
this scheme, a range of developers received varying levels of public funding to build so-
cial housing using natural renewable materials, resulting in the construction of around 200
homes. Of the twelve projects funded, seven used hempcrete as an insulation material.
Since the UK construction industry is notoriously slow to adopt new practices, and has
been largely sceptical of the need for (or even the possibility of) using natural materials,
State-funded and -driven programmes such as the Renewable House Programme are in-
valuable in facilitating investigation into issues relating to the largescale adoption of nat-
ural materials within the construction sector. The programme certainly had its challenges,
and many of the projects undertaken suffered to some extent from the effects of contractors
being given novel materials to work with. However, the overall results were encouraging,
and no problems were encountered to suggest that hempcrete, along with other natural ma-
terials, would not be suitable for adoption on an increasing scale within the mainstream
construction industry.
There are also some other uses of the hemp plant in construction, primarily of the bast
fibres in the manufacture of fibre quilt insulation materials, and both shiv and bast fibre
as an addition to lime plasters, providing additional strength and some insulation to the
plaster. While these materials are not the main focus of this topic, they are occasionally
referred to throughout, so a brief overview of them is included later in this chapter. First,
however, we look at the different ways in which hempcrete can be used.
Hemp shiv for building
Currently in the UK there are no agreed standards for the characteristics of hemp shiv for
the construction industry, nor for its production or processing. In France, where the hemp
building industry is more established, there are strict guidelines for hemp farmers that gov-
ern the quality and colour of hemp shiv to be used in construction, and it is hoped that, in