Straw houses could unlock potential for ultra-low-carbon homes
Straw panels have been used to build seven eco-homes in Bristol in a first for a low-cost and fuel efficient building material which promises to reduce heating bills by 90% over that of brick-built housing.
The new Modcell factory-built straw panels, going on sale this week, have been developed with the University of Bath's department of architecture and civil engineering.
University of Bath professor Pete Walker said: "The construction sector must reduce its energy consumption by 50% and its carbon emissions by 80% by 2050, so radical changes are needed to the way we approach house building.
"As a construction material straw is a low-cost and widely available food co-product that offers real potential for ultra-low carbon housing throughout the UK. Building with straw could be a critical point in our trajectory towards a low-carbon future."
The 3.2m by 2.9m panels consist of a timber frame enclosing compressed straw bale insulation. When constructed in an airtight design in conjunction with triple glazed windows, the panels will provide three times greater insulation than required by current UK building regulations.
The panels have received BM Trada's Q mark certification, allowing developers and home owners to insure and secure mortgages against buildings constructed with the panels making this the first affordable, low-carbon and fuel-efficient means of house building to enter the market.
Craig White of ModCell commented: "The Q mark industry certification means that straw is now a viable, affordable means of tackling the housing crisis in the UK. Using a 'fabric first' approach is ideal for private homes, social housing, and new, innovative projects such as custom-build. Straw now offers a simple and effective home-grown solution to the UK's housing needs."
Producing straw for use in buildings on a large scale would result in a negative carbon footprint, as unlike conventional materials such as brick or cement, straw absorbs CO2 as it grows. It would also cut waste as straw is already an agricultural co-product.
Seven million tonnes of straw remain after the production of wheat flour in the UK, of which half currently is discarded to be used as animal bedding due to its low value. This remaining 3.8 million tonnes of straw could be used to build over 500,000 new homes, as an average three-bedroom house needs 7.2 tonnes of straw.
Residents at the multi-award-winning LILAC straw-built co-housing community in Bramley, West Leeds, have already benefitted from 90% cheaper energy bills and 20% lower building costs than on average in Leeds. The potential of straw as a building material is also being recognised worldwide as straw bale construction continues to steadily increase with buildings found in USA, Australia and China.
Last week saw a push towards improving the energy efficiency of homes in the UK as new rules forcing landlords to upgrade the energy efficiency of let properties were announced by the government. By April 2018 landlords in England and Wales will have to ensure their properties have an energy efficient rating of at least Band E.
Video: Straw building certification
Sustainability Live 2015
Energy-efficient buildings will be a key theme at Sustainability Live 2015 in April, with a number of keynote sessions and panel discussions focusing on the opportunities for improving building performance and energy efficiency, retrofit strategies and the future energy management of commercial propertieis.
Find out more and register to attend Sustainability Live 2015 here.