BRE Centre for Innovative Construction Materials

White Design’s BaleHaus explores the use of prefabricated straw panels for mass housing

By Michael Stacey, BD

The BaleHaus was designed by architect Craig White of White Design as part of a multi-disciplinary research project by Katharine Beadle at the University of Bath’s BRE Centre for Innovative Construction Materials.

The aim of this project is to demonstrate that straw is an appropriate form of insulation and structure for current mass housing. This probably explains why the house has been designed to meet Code for Sustainable Homes Level 4 and not Code Level 6 or “zero carbon”. Code level 4 represents a 44% reduction of energy used and CO2 emissions when compared to current building regulations.

The BaleHaus is constructed from ModCell panels which are prefabricated from locally sourced materials; the panels have a timber frame and are filled with straw. This is then covered with a lime render. The timber frame takes the vertical loads and the rendered straw infill takes in-plane or racking loads. This structural principle was tested at the University of Bath.

Exterior of the BaleHaus prototype which has been built on the campus of the University of Bath.

By Eco Composites, Writer

A visit to the Innovation Park at BRE in Watford has been arranged as part of the Natural Fibres 09 conference, which takes place at the Institute of Materials, Minerals and Mining in London from December 14-16.

The park showcases modern methods of construction and features over 200 different emerging technologies in a number of demonstration properties, including the Renewable Hemp House.

Speaking at the 60th annual congress of CELC – the European Confederation of Flax and Hemp – which took place in Strasbourg, France, from November 4-7, Claude Eichwald of French organisation Construire de Chanvre, said that the use of hemp in concrete was growing, with between 2-4,000 houses now constructed completely from hemp concrete, and many more employing it with mixtures of other building materials. The CELC conference also heard from Rémi Perrin of Strasbourg-based Soprema, which is now manufacturing flax roofing membranes, and Vincent de Sutter of Sutter Freres which has been making natural-fibre based door panels for almost 50 years.

In the latest copy of its journal, CELC outlines the components of a house entirely constructed from natural fibres, as show in the illustration above.

The unique energy efficient house made from hemp at the UK BRE Innovation Park meanwhile, showcases the future of low carbon and sustainable buildings.

The environmental potential of hemp as a building material has never really been in doubt - it absorbs carbon as it grows and can be grown almost anywhere, cutting down on the need for energy-intensive transportation.

But is it any good?

A study underway at the BRE Centre for Innovative Construction Materials at the University of Bath is attempting to clear up any doubts.

"The idea of using hemp and lime has been around in the UK for ten or 12 years now and there have been a number of applications but there's still relatively little scientific information on the performance of the materials," Prof Pete Walker, director of the centre, told edie.

"We've identified this as a significant barrier to market uptake."

He said that mainstream engineers, architects and buyers were shying away from a potential tool in the fight against climate change due to the absence of reliable independent information on its characteristics.

The research project is providing concrete answers to the questions of the construction industry and also experimenting with different ratios of hemp to lime in an effort to maximise its carbon cutting potential.

"The lime has all the embodied carbon and energy and, if we're honest, the cost," said Prof Walker.

"The hemp offsets this. Using renewable crops to make building materials makes real sense - it only takes an area the size of a rugby pitch four months to grow enough hemp to build a typical three bedroom house.

By Press Association

A form of cannabis could be used to build carbon-neutral homes of the future, university researchers have said.

A consortium, led by the BRE Centre for Innovative Construction Materials at the University of Bath, has embarked on a housing project to develop the use of construction materials made of hemp.

Hemp-lime is a lightweight building material made of fibres from the fast-growing cannabis plant, bound together using a lime-based adhesive.

The hemp plant stores carbon during its growth and this, combined with the low carbon footprint of lime and its efficient insulating properties, gives the material a "better than zero carbon" footprint, researchers said.

Professor Pete Walker, director of the BRE Centre for Innovative Construction Materials, said: "We will be looking at the feasibility of using hemp-lime in place of traditional materials, so that they can be used widely in the building industry.

"We will be measuring the properties of lime-hemp materials, such as their strength and durability, as well as the energy efficiency of buildings made of these materials.

"Using renewable crops to make building materials makes real sense - it only takes an area the size of a rugby pitch four months to grow enough hemp to build a typical three bedroom house."