House made of straw 'passes fire test'

A house made of straw and hemp panels has passed a fire resistance test where it was exposed to temperatures over 1000°C, a university said today.

Balehaus@Bath - built of pre-fabricated straw-bale and hemp sections - has fire resistance "as good as houses built of conventional building materials", according to new research.

One of the panels used in the construction was exposed to the searing heat by the University of Bristol team.

To reach the required standard the panel had to withstand the heat for more than 30 minutes.

Over two hours later - four times as long as required - the panel had still not failed.

The house is made from prefabricated cells of timber filled with straw or hemp, rendered with a lime-based coat.

BaleHaus@Bath is part of a research project into how renewable building materials can be used for homes of the future.

The research work on BaleHaus has been funded by Carbon Connections and the Technology Strategy Board.

Construction materials researchers from the university will also be monitoring the house for a year for its insulating properties, humidity levels, air tightness and sound insulation.

The ModCell BaleHaus system is the brainchild of White Design in Bristol and Integral Structural Design in Bath.

It was used last year by Kevin McCloud to build an eco-friendly house in six days for the Grand Designs Live exhibition.

ModCell is carbon negative in manufacture.

Due to the high insulating properties of the panels, the BaleHaus minimises additional heating requirements, reducing heating bills in housing by up to 85% and CO2 emissions by 60%.

Mr McCloud, who is due to officially open the BaleHaus@Bath later today, said: "I welcome the ongoing testing on the Balehaus. I expect the results will show people that we can minimise the use of highly processed materials in building and genuinely make use of such sustainable building materials.

"It's vital that we encourage people to recycle, insulate and minimise the use of fossil fuels to keep our buildings warm."

Professor Pete Walker, director of the University's BRE Centre in Innovative Construction Materials said: "Straw is an ideal environmentally-friendly building material because it is renewable and is a by-product of existing farming production.

"Whilst we've previously done tests on individual ModCell panels, this is the first time data have been collected from a complete house. We're hoping this will lead to these renewable materials being used more widely in the building industry for housing in the UK.

"The crop used for the straw can be grown locally, and because it absorbs carbon dioxide as it grows, buildings made from it have a very low carbon footprint."

Craig White, director of ModCell, said: "It is unacceptable that 27% of CO2 emissions currently come from the energy we use in our homes, it is just as unacceptable to continue to emit CO2 through the energy we use to make them.

"If we are completely serious about being 'carbon free' we need to rethink the design of our buildings on a large scale.

"The ModCell BaleHaus system is designed to deliver just such a sustainable method of construction. These tests will offer proof that sustainable building materials are a realistic option for building on a large scale."