Axel Simon contrasts the angular Swiss architecture with an entirely different exemplary project – a timber construction that looks quite conservative from the outside but is all the more interesting programmatically as the building materials were obtained from a neighbouring forest.

Sustainability – an awkward term but one without which modern building cannot get along. Apart from more efficient techniques and tighter lodgings, sustainability requires an acknowledgement of the actual place and its material and workforce resources: slow Architecture. That by choosing such an approach not only “eco houses” – more or less funny oddities - can emerge but also really serious architecture is demonstrated by the Büttenhardt vacation home designed by Bernath+Widmer architects.

From Schaffhausen one has to drive for 15 minutes through undulating fields and then through a typically Swiss mixed forest. The farm with the “vacation home” – the dilapidated predecessor building was one indeed - is to be found at the edge of a vast, idyllic clearing. Actually, the new annexe to the farmhouse is occupied by up to 6 young persons who stay here for some months within the context of a special care programme. Those young persons who were living in the facility at the time took part in the erection of the new two-storey wooden house. That new building had been initiated by an old local mechanic engineer. Driven by the obsession to build houses of endemic deciduous wood he had devised a 2.6 m long drill that is able to remove the heartwood from thick beams. Deciduous wood without its core dries faster, is less prone to tears, and even thin logs can thus be cut into beams while otherwise these could only serve as firewood. Thus, the maintenance of the forest, which is needed anyway, resulted in building a house as a by-product, so to speak.

The young architects examined the wood that had been cut during the winter of 2007. Thick and thin, long and short logs had been piled on both sides of the road before the farm. All in all, there were 500 cubic metres of wood. With reference to the timber list, the building was planned in collaboration with a specialist log house builder. The maximum drill length translated into an axial dimension of 5.2 metres, the different varieties of timber were used according to their respective properties. Mobile ribbon saws were used to cut the logs on site, in the next village the heartwood was drilled out. After that, the beams were left for a year to dry before carpenters mounted the cut-to-size/scribed elements on the concrete basement.

For the outer frame of the balloon framing construction weatherproof oak beams (measuring 20 x 20 centimetres) were used and filled in with pine planks (8-14 centimetres thick). In the interior, beech has been used for most of the load-bearing elements – of the hardwood that had been cut beech was most, but beech wood should not be exposed to the weather. And, of course, the floors, stairs, railings, and embrasures were also made of local wood – amounting to roughly 90 percent of the materials used in the house. The house has been erected glue-free, hence healthy, and by using regrowing, locally produced and processed materials. Thus it is, in a word, a “green” house.

The firewood piled at the forest’s edge clearly indicates for what purpose the valuable beech, oak, and maple trees had been used in the past. The new vacation home in Büttenhardt furnishes evidence for quite another use. As such, this building is an innovative project.

Fakten
Architekten Bernath+Widmer, Zürich

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aus Bauwelt 43.2010
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