Environmental benefits of using cross-laminated timber with hempcrete insulation in buildings

The build environment, one of the largest energy consumers, is also responsible for around 40% of CO2 emissions in Europe. Under the threat of climate change, legislators and policy-makers keep amending building-related regulations and standards to diminish the building industry’s impact on the environment. Along with this trend architectural practices, one of the main generators of innovation in the built environment, have been shifting towards more sustainable designs and use of materials in construction. Part of this endeavour is represented by the recently increased use of cross-laminated timber (CLT) in high-rise buildings and the expansion of hempcrete use. Both of these materials are becoming increasingly popular due to the benefits they offer to a sustainable building economy due to their specific characteristics. Both CLT, made out of cross bonded hardwood panels, and hempcrete, a dried mixture of lime and woody fibres extracted from hemp, have very low embodied energy and also locked CO2 during their growth. Hempcrete has also excellent thermal properties. However, so far they have been considered separately in construction. Thus this paper investigates the environmental benefits of using them together, pondering the pros and cons of doing so. Specifically, it explores the performance CLT and hempcrete together can achieve with a construction technique using a panel of CLT with hempcrete as insulation. The research method used is material exploration and computer modelling with the use of dynamic energy simulation.