Born in a barn
A new affordable home design takes its inspiration from agricultural buildings, with straw bales for insulation and heating bills to envy. Paul Sawtell and John Carter report
AT LAST, IN THE RUN-IN to May’s general election, the housing ‘crisis’ is hitting the headlines. Informed commentators would, no doubt, wish to phrase the headline more accurately as an ‘affordable housing crisis’ which means an increasing number of people in the UK cannot afford to buy a home of their own. The change over the past 30 years was illustrated by Mariella Frostrup in a recent edition of BBC’s Panorama programme. She went back to visit her first home, purchased for £40,000, when she was earning £10,000 per annum. The new owner had recently purchased it for £400,000. She did not say if she was a first-time buyer or if she was earning £100,000 per annum. The inference is clear. What had been affordable by a first-time buyer 30 years ago is no longer affordable today.
This affordability criterion was one of the challenges that Valleys to Coast Housing Association (V2C) felt could be addressed when it teamed up with Cardiff-based Pentan Architects to develop Pentan’s competition-winning Barnhaus project. Barnhaus was borne out of a competition organised by the National Self-Build Association (NaSBA) and Grand Designs to design an affordable, easily-buildable house. For his solution to the competition brief, Pentan’s Ed Green turned to low-cost agricultural buildings for inspiration. On the basis that farmers, through necessity, often work to very tight budgets, he took a small, low-cost agricultural steel-framed barn and turned it into
a house – complete with straw bales for insulation and corrugated cladding and timber-boarded facades!
Pentan coined the name Barnhaus to describe its design: ‘barn’ because of its agricultural starting point; and ‘haus’, the German for ‘house’, to signify its engineered quality. No shoddy workmanship allowed!
V2C immediately saw the potential in this idea. It is now working hard with Pentan to turn the vision into reality, via a four-house Barnhaus project in the Bridgend area, for which it has recently received planning permission. The V2C-Pentan team have evolved the original competition-winning concept into an elegant, easy-to-construct kit-of-parts that can be used by both self-builders and building contractors. The Barnhaus construction method exceeds current building regulations standards in Wales, leading to reduced heating bills (see annual heating hills table, below). And, with modest thermal insulation and air-tightness up- grades, can also achieve the rigorous Passivhaus energy standard. This is approximately one tenth of the annual heating load of an equivalent-sized house built to recent building regulations.
Another advantage of Barnhaus is that it is adaptable in the future. If you want to change the rooms around, you can do so, because none of the internal walls are load-bearing. If your plot is big enough and you want to extend, as your family grows, you can add another bay (or two!) – just as a farmer might extend a barn. Conversely, if you need less space, later in life, you can easily de- construct part of the house; or take some walls away and leave the roof, to create a sheltered outdoor space or first-floor balcony. This adaptability is facilitated by the essentially dry construction method of Barnhaus. For example, walls are lined with plasterboard or fire- proofed timber boards; so that they can be taken apart and re-used more easily than plastered blockwork walls.
A very important aspect of the Barnhaus design for V2C and Pentan is that, when compared to an equivalent-cost house, it offers more space for the same money. This means it helps to counter the ‘squeeze’ on floor areas that has characterised recent housing trends in the UK.
As V2C’s Paul Sawtell puts it: ‘The Barnhaus concept can be a significant opportunity to provide affordable housing for the future.’ He believes V2C is particularly well placed to use knowledge gained over the last decade from successful building works and repairs to overcome the issues in their non-traditional properties to ensure these ‘old’ repair problems are designed-out. This should ensure a greater longevity for these new properties compared to the previous non-traditional systems of building.’
Of course, the proof of the pudding is in the eating, and V2C and Pentan recognise that there is more work to be done before building starts later this year. However, they firmly believe that Barnhaus can make a positive contribution to the massive challenge that is the affordable housing crisis. Pentan also has planning permission for a scheme in Scotland and is talking to planning authorities in the Vale of Glamorgan and in England.
Paul Sawtell is development manager at Valleys to Coast Housing Association. John Carter is director, Pentan Architects