In June 2014 we decided to replace the old concrete room at the back of the house. We needed a space in which to host events, that would hold a good sized group of people, be efficient, and built from natural materials. We decided to part fund the build through a crowdfunding campaign, which was successful, and to involve as many people as possible with the build itself.
The construction is a simple one. A timber frame sits on a low foundation wall, protected on the outside by a breather membrane and larch cladding. The frame itself is then insulated with sheep’s wool, and then internally, strawbale provides insulation and internal walls, which are plastered with clay found locally, and painted with home-made clay paints. The floor is larch, sourced locally, and it sits above a thick layer of foamed glass insulation.
The roof is substantial – a deck of sawmill waste planking is covered with a breather membrane, over which sits a layer of straw bales, which are covered with a butyl rubber membrane. Old plastic silage sheet has been added on top to protect the butyl rubber, and finally a layer of old carpet added to give the soil covering something to grip to. The soil itself is around 4 inches or 100mm thick, and has self seeded. We used turf from a huge rock outcrop next to the house on the basis that the things growing there would be tolerant of shallow soil. The roof is edged with larch planking to finish it off.