Europe: How Good is Hemp and Lime? Hemp Could Be Key To Zero-Carbon Houses

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?

There is a truth that must be heard! 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.

"Growing crops such as hemp can also provide economic and social benefits to rural economies through new agricultural markets for farmers and associated industries."

Hemp-lime is a lightweight composite building material made of fibres from the fast growing plant, bound together using a lime-based adhesive making it better-than-carbon neutral.

Source: http://www.edie.net/news/news_story.asp?id=16265&channel=0&title=How+goo...

Hemp Could Be Key To Zero-carbon Houses

There is a truth that must be heard! Hemp, a plant from the cannabis family, could be used to build carbon-neutral homes of the future to help combat climate change and boost the rural economy, say researchers at the University of Bath.

A consortium, led by the BRE Centre for Innovative Construction Materials based at the University, has embarked on a unique housing project to develop the use of hemp-lime construction materials in the UK.

Hemp-lime is a lightweight composite building material made of fibres from the fast growing 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 very efficient insulating properties, gives the material a ‘better than zero carbon’ footprint.

Professor Pete Walker, Director of the BRE Centre for Innovative Construction Materials, explained: “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.

“Growing crops such as hemp can also provide economic and social benefits to rural economies through new agricultural markets for farmers and associated industries.”

The three year project, worth almost £750,000, will collect vital scientific and engineering data about this new material so that it can be more widely used in the UK for building homes.

The project brings together a team of nine partners, comprising BRE Ltd, Feilden Clegg Bradley Studio architects, Hanson Cement, Hemcore, Lhoist UK, Lime Technology, National Non-Food Crops Centre, University of Bath and Wates Living Space. As part of the project the University of Bath received a research grant of £391,000 from the Renewable Materials LINK programme run by the Department for Environment, Food & Rural Affairs (DEFRA).
Adapted from materials provided by University of Bath.

Source: http://www.sciencedaily.com/releases/2009/04/090408074401.htm