Built from scratch
This remarkable house, build by the architects Martin Rauch and Roger Boltshauseris is completely made out of rammed earth, literally build from scratch. It is located in the western outskirts of Austria, in the town Schlins. Its unimposing appearance might be misleading at first sight, a closer look reveals impressing features, thoughtful details and an outstanding approach to the use of natural materials.
The aim was to create a building that could fully disintegrate after its lifetime, without leaving any residues. It is located on a slope and 41% of the volume of the house is underground. 85% of the building materials were obtained from the excavated earth on site and used for the foundation, the exterior walls as well as the interior. Even the tiles, the washbasin and kitchen were made out of the same material, fabricated at a workshop nearby by local craftsman.
For the main structure of the building, a mixture of clay and gravel is compressed periodically in horizontal layers with air compression beaters and vibration rolls till the highest possible density is achieved. This technique makes it possible to build without cement, since the clay acts as the binding material, holding the gravel together.
None of the walls are treated or painted, the architects wanted to show authenticity by revealing the structural materials. As the materials are without protection, erosion cannot be completely avoided. Rauch calls it “the calculated erosion”. He added an effective detail on the exterior facade, brick layers that stick out of the wall not only to emphasize the horizontality and stability of the building but to act as a speed breaker for the rain and to prevent irregular deformation of the wall.
All the walls are load barring and have a thickness of 45 cm. An insulation made out of 10 cm thick reed matts is added on the inside of the walls.
The floor is partly covered with earth tiles, fired at 900 °C or made out of oiled and waxed rammed earth, allowing a fire place to be in direct contact with the floor. The interior walls are plastered with polished white clay, creating a warm atmosphere and allowing the walls to breath.
The joints between windows and wall are reduced to the symbiosis of wood and earth, no silicon seals, no protection. The window frames are made out of handcrafted oakwood. The mud is very dry and absorbs the water from the wood, making it possible to leave the wood untreated and in direct contact with the earth wall.
Another beautiful feature of the house is the staircase. The steps that stick out of the wall, show the impressive strength and the unexpected potential of rammed earth.
The energy needed for heating and hot water comes from 100% renewable energy sources. The building contains solar heating and makes use of the thermal mass of the walls.
The Rauch house is an outstanding example for building with natural material, it not only sets new standards in terms of integrating vernacular building techniques in contemporary architecture but also emphasizes the beauty of merging harmoniously with the surrounding environment.