Hemp-lime: highlighting room for improvement

Abstract

Greenhouse Gas Emissions and growing energy demands are global issues that are exacerbated by the construction industry; an industry whose activities make up the majority of most country’s emissions, while the Housing Sector alone expends 60% of its total energy consumption on space heating of buildings [1]. Materials are continually being developed to be more environmentally friendly and reduce the carbon foot-print of buildings. Hemp-lime is a natural material that sequesters CO₂ during growth of the hemp plant through photosynthesis; this reduces the material’s carbon footprint, allowing potential construction of ‘zero carbon’ buildings. The simple homogeneous construction of a hemp-lime building exhibits a good thermal performance, which can dampen fluctuations in external temperature and passively control internal humidity. This considerably reduces the demand on internal heating and cooling thus reducing the energy consumed within the building. Hemp-lime construction can be conducted in a number of ways including manual placement and spraying. This paper outlines some of the issues arising from differing construction methods, highlighting gaps in the knowledge and understanding of the use of this natural material. The paper concludes by presenting topics for further research in order to improve and promote hemp-lime use within the construction sector.