Houses made of STRAW went on the open market for the first time yesterday (Mon) after being made eligible for mortgages.
Until now the eco-homes have been the preserve of bespoke building projects and financed through specialist lenders.
But a row of seven straw houses in Bristol have now become the first to secure building certification which makes them eligible for a standard mortgage.
The two and three-bedroom properties will each use more than seven tonnes of straw and reduce heating costs by 90 per cent compared to the average brick house.
They are due to be completed in April but went on the open market yesterday priced between £220,000 and £240,000.
Professor Pete Walker from the University of Bath, who led a project to develop and test the construction method, hailed straw as the future of building.
He said: “I think there’s a lot of misconception about using straw – stories about the three little pigs and the big bad wolf, concerns about fire resistance.
“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 great thing about the houses is that they are affordable and in addition the energy costs will be extremely low – under £100 a year.”
The houses are currently undergoing a ten-week construction programme by developers Connolly and Callaghan in Shirehampton, Bristol.
Each wall is the same thickness as a normal bale of straw, framed in timber and encased in wooden boards.
In addition compressed straw board will line the walls throughout the house as a replacement for plaster board.
Once built, the terraced houses will be clad in brick so they will be indistinguishable from the other properties in the street.
The only hint of their remarkable construction method will be a ‘truth window’ in each property where a section of straw wall will be visible through a window.
Although these are not the first houses in the UK to be built using straw bales, they are the first to be built for any buyer on the open market.
The straw design has received BM Trada’s Q mark certification, meaning developers and house buyers can now insure and secure mortgages against the homes.
Prof Walker, who spent ten years researching the design, added: “First and foremost the work has demonstrated that straw bales create safe, durable and affordable houses.
“They make contributions to reducing fuel poverty and make significant contributions to reducing energy bills of building occupants.
“There are wider benefits. Buildings contribute around 50 per cent of the carbon emissions in this country.
“By producing lower carbon buildings – buildings such as straw bales and other techniques – can help the government meet its international targets of reducing carbon emissions by 80 per cent by 2015.”
Just under four million tonnes of leftover straw is produced every year by UK agriculture, according to the Agricultural and Horticultural Development Board.
That means there is potential to grow the material for more than half a million new homes every year in British fields.
To receive certification research tested the straw panel’s energy efficiency, fire safety, durability and weather-resilience, including exposing the panels to heavy rain and extreme temperatures ranging from -20 degrees to 50 degrees.
Craig White, director of Modcell, the architectural firm involved in the project, explained: “Previously, you’d have a client in place, they knew they wanted a straw bale construction, and they would commission us to deliver that.
“These are the first ones being built speculatively, for the open market. I think it’s a very exciting time for this building technology.
“And the more we can build out of renewable materials like straw and timber, the less carbon will be in the atmosphere, so we can reduce climate change effects.”