Hemp and straw 'house of future' goes up in Bath

A “BaleHaus” made of prefabricated straw bales and hemp cladding panels will soon be going up on the campus of the University of Bath, and people around the world will be able to watch the construction progress online via “Strawcam” from Monday 20 July.

Researchers at the university are putting up the structure to test whether such materials could yield the buildings of the future.

A BaleHaus Website will also features blogs, videos, photos and lots of other information about the project.

Straw is the ultimate environmentally-friendly building material, since it is renewable and is a by-product of farming. The crop used for the straw can be grown locally, and — because the plants absorb carbon dioxide as they grow — buildings made from straw can be seen as having a zero-carbon, or even a negative-carbon, footprint.

Due to straw’s high insulating properties, houses made of straw bales also need almost no conventional heating, keeping running costs low and minimising environmental impact.

The research team at the University of Bath will be assessing straw bales and hemp as building materials so that they can be used more widely in the building industry for housing, helping the UK achieve its targets for reducing carbon emissions.

The two-storey BaleHaus to be built on campus will be made using “ModCell” — pre-fabricated panels consisting of a wooden structural frame infilled with straw bales or hemp and rendered with a breathable lime-based system.

ModCell is the creation of White Design in Bristol and Integral Structural Design in Bath. Other partners on the research project are Agrifibre Technologies, Lime Technology, Eurban, the Centre for Window & Cladding Technology and Willmott Dixon.

Some of the building has already appeared in the media spotlight. Last year, the team helped Kevin McCloud, presenter of Channel 4’s “Grand Designs” programme, to build an eco-friendly house in six days using ModCell panels for the “Grand Designs Live” exhibition.

All the wall panels used for the ground floor of the Grand Designs house are being reused for the BaleHaus at Bath.

“Up to this point, straw bales have not really been seen as a credible building material by much of the industry, even though straw has always been used in building for centuries, and straw bales have been used for about 100 years,” said Pete Walker, director of the BRE Centre in Innovative Construction Materials at the university. “Straw bales are an agricultural by-product and the material can be re-grown so is totally sustainable and renewable. The straw can be grown on a farm that is local to the construction site which saves on transport and minimises the carbon footprint of the building.”

The BaleHaus at Bath, due to be completed in the late summer, will be monitored for a year for its insulating properties, humidity levels, air tightness and sound insulation qualities.

“We’re putting sensors into the walls to monitor temperature and humidity levels, and using technology to simulate the heat and moisture generated by people,” said Katharine Beadle, the principle researcher on the project.

Added Craig White, director of White Design and ModCell, “The Zero Carbon Housing challenge the industry faces is not going to be met with conventional design and materials. BaleHaus at Bath is an entirely new and renewable way to construct homes fit for the challenge.”