From the outside, Phil Gawne MHK’s house extension looks like a traditional timber-framed, timber-clad building, beautifully finished with larch shiplap. But when you go inside, the uneven clay and lime-plastered walls and the wonderful mediaeval-style exposed wooden beams give you a clue that there’s something a bit different behind the plaster.
‘We needed an extension on our two-up two-down cottage,’ said Phil, ‘and I got a quote for both conventional and less-conventional style builds. The costs were similar, but as straw bale homes require much less heating, I felt straw would be cheaper in the long run.’
Now, after a couple of years planning and building, the family has just had its first Christmas in its new straw bale extension.
‘It was wonderful,’ Phil said. ‘The building looks fantastic, and the straw bale side of the house is so warm compared with the rest.’
Both Phil and the architect, James Hampton, who designed and built the extension, felt they should use materials occurring naturally in the Isle of Man or which could be grown here. Straw is abundant, a by-product of grain production, and the inside of the house is plastered with clay, a waste product of the aggregate washing process at Corlett’s.
While the timber frame and lime finishing were sourced from elsewhere, they could be locally produced. Both are available in the island, but currently the processing ability has been lost. This could change if enough people chose this building method.
James graduated with a BA Hons in architecture and an MSc in environment and sustainable development/development planning.
He told me: ‘When I finished my degree I was pretty much set on being a professional architect with a nice shiny new BMW, but I came to realise that if you want to do anything really special in architecture then you have to do it yourself.’
Even so, he says he only became interested in environmentally-friendly building by accident.
‘A friend was booked on the 2004 European Architecture Students’ Assembly in Denmark, but then decided they couldn’t go and I took the place. At EASA you choose a two-week workshop. One of the guys running a course was Lars Keller, one of the world leaders in straw bale building. It was meeting and working with him that got me into it.’
Interestingly, ecology was not James’s first interest.
‘What impressed me was that you could build a phenomenally well-insulated house for buttons. If you try to get the same level of insulation with modern materials, it would cost a huge amount more. A straw bale costs £3.50, but a comparable area and thickness of Kingspan insulation might cost 80 quid. It really doesn’t add up.
‘I’m struck by the inefficiency of the building trade, in terms of money, time and energy. Modern processes are so wasteful. A prime example is the energy and cost of producing steel. A steel-framed building is cheap, but look at the energy used in the production and transportation of that steel.
‘If instead you were to do the same frame in timber it would take a fraction of the cost and energy. Plastic window frames also take loads of energy to produce and they have a life span of 20, or 25 years before they fall to pieces because they’re not UV-stable. A well-made timber window frame might last for a couple of hundred years if you look after it.’
James is certain that straw bales will stand the test of time.
The oldest straw bale houses, in Nebraska, are about a couple of hundred years old and they’ve shown no real signs of deterioration. It all comes down to design. Design it right - it’ll last.’
While many straw bale houses are actually free-standing timber-framed structures using straw as infill and insulation material, straw bales can also be load-bearing. In America there are warehouses and even three-storey buildings made simply by piling straw bales on top of each other.
A roof is then placed on top to compress them and weigh them down. Phil Gawne’s house is a hybrid. The timber frame is doing most of the work and then straw bale panels have been used to fill the gaps between timber members. The roof has been constructed in the same way.
Phil said that the building process was relatively trouble-free,
‘There were a few little issues along the way. We certainly challenged Building Control – but it’s fair to say they were very supportive, helpful and prepared to learn as they went along.’
In particular, it seems that people’s instincts in terms of wood and straw are to think there will be a fire risk, but as James pointed out, ‘Straw bales are fully approved in Scandinavia, and they’re actually more fire-resistant than a lot of other building materials.
There’s no air in compressed straw bales, so they burn very slowly. A wooden frame, straw bale house like Phil’s will take seven or eight hours to burn, whereas if it had been built in plastic and steel it’d be on the deck in probably under half an hour.’
Currently it would be fair to say that the straw bale house fulfils a niche market, but James feels they could become mainstream.
‘My perception is that kit-building is the way forward. Kit structures are already a mainstream building technique. All of your modern, cut price, buildings are done with timber kits because they’re fast and cheap – and there are already companies in the UK building straw bale houses from kits.
It really just takes a marriage between the people who understand kits from the other end of the spectrum to get their heads around straw bales.
‘The next one we’re doing will be a proper kit-build to see if we can do it a bit faster and a bit more cheaply. We’ll build the wall and roof panels in our yard, and then take them across to the site before we actually construct the building.
‘In Phil’s house the wall edges are rounded off, but that’s a design feature. If people want a flat finish, you can get that with a panelled kit version.’
Despite the potential, it will take Government action for sustainable buildings to compete with mainstream house-building methods. Building regulations would need to be tightened, perhaps to Scandinavian standards. Phil recognises the problem.
‘As Infrastructure Minister I did get a bill through Tynwald significantly improving the building regulations, but they could be better, and the initial draft was much stronger than the one finally agreed.’
As well as making environmental sense, more straw bale building would also help the Island’s economy. ‘It just seems ridiculous in an age when we know oil is becoming more scarce to continue using so many oil-dependent building materials,’ said Phil. ‘We have a very effective natural product here at home, which is cheaper and potentially safer. In my book it’s better to support local jobs and keep money on the island. Maybe this is something I can encourage more in my current position as DEFA Minister.’
Phil Gawne is the Minister of Environment, Food and Agriculture.
Architect James Hampton of Manninwood Traditional Carpentry can be contacted via www.manninwood.com, or by calling 434044.