Hemp can be used to build environmentally-friendly homes of the future say researchers at the University of Bath
A consortium, led by the Building Research Establishment (BRE) Centre for Innovative Construction Materials based at the University, has constructed a small building on the Claverton campus out of hemp-lime to test its properties as a building material.
Called the ‘HemPod’, this one-storey building has highly insulating walls made from the chopped woody core, or shiv, of the industrial hemp plant mixed with a specially developed lime-based binder. The hemp shiv traps air in the walls, and the hemp itself is porous, making the walls incredibly well insulated. The lime-based binder sticks together and protects the hemp and makes the building material highly fire resistant.
The industrial hemp plant takes in carbon dioxide as it grows, and the lime render absorbs even more of the climate change gas, effectively giving the building an extremely low carbon footprint.
Dr Mike Lawrence, Research Officer from the University’s Department of Architecture & Civil Engineering, explained: “Whilst there are already some houses in the UK built using hemp and lime, the HemPod will be the first hemp-lime building to be constructed purely for scientific testing. We will be closely monitoring the house for 18 months using temperature and humidity sensors buried in the walls, measuring how quickly heat and water vapour travels through them.”
Environmentally-friendly building materials are often more expensive than traditional materials, but the Renewable House project funded by the Department of Energy and Climate Change (DECC) and the National Non-Food Crops Centre (NNFCC) demonstrated a cost of around £75,000 (excluding foundations) to build a three-bedroom ‘Code 4' house from hemp-lime making it competitive with conventional bricks and mortar.