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Renovation

The original form of the former duplex farmhouse, which was built 250 years ago by the Winterthur Hospital Board to house tenants, is no longer so easy to discern. The extension carried out around 100 years ago significantly altered the size of the building. The partition wall that separated the building parallel to the roof ridge—an architectural feature that was uncommon in the Zurich Highlands—has been brought back to life with a brand new partition.

«Beautiful Switzerland»: clay as a building material

In addition to wood, clay is increasingly being used as a building material. A visit to the Zurich Oberland shows the challenges posed by this rediscovered building material.

Schweiz Aktuell 30.07.2024

Clay building

People have been building their homes out of clay since time immemorial - in Switzerland mainly as timber infill. There is sufficient clay available all over the world and a third of humanity lives in clay houses. Clay earth has excellent sorption and desorption properties. It ensures a balanced moisture balance in the living space, which makes for a very pleasant microclimate and healthy comfort.

Clay is a very good heat accumulator. Constructions with heavy clay have excellent sound insulation values. Clay earth has an excellent energy and pollutant balance. Clay earth is easy to work with, kind to the skin and waste-free: it does not set chemically and can be recycled again and again with water. Clay earth is an ecologically and economically sensible and natural building material. It is available in sufficient quantities.

Clay is able to absorb humidity quickly and release it again when required. As a result, the relative humidity in rooms equipped with clay products is between 45% and 55%. In such a room climate, the mucous membranes do not dry out and the formation of fine dust is reduced. Mold and house dust mites also thrive less well in such a microclimate, which should please house dust allergy sufferers. In winter, rooms equipped with clay have a warm effect and in summer they are cool.

Half-timbered walls

The only two remaining internal half-timbered walls have been uncovered and remain visible.

The new partition wall, which supports the building as a load-bearing wall on the two lower levels, is in dialogue with the old half-timbered walls. This supports the central axis of the building. The old floor joists remain in place. We separated them and fixed them to new beams, which are supported by pillars. This allowed the floor to be straightened slightly and the ceiling heights to be raised.

Forest - Load-bearing wall

The new partition wall, which supports the building as a load-bearing wall on the two lower levels, is in dialogue with the old half-timbered walls. This supports the central axis of the building. The old floor joists remain in place. We separated them and fixed them to new beams, which are supported by pillars. This allowed the floor to be straightened slightly and the ceiling heights to be raised.

EG Waldwand

OG Waldwand

DG Waldwand

DG 2 Waldwand

Moon wood

All of the woodwork, with the exception of the central load-bearing wall, is made of moon wood; felled in the winter of 2022 on the Bachtel mountain. The windows have also been cut from this wood and are entirely natural.

Colour concept

The old window jambs made of sandstone from the Obersee lake have now been replaced with new ones and create a bold impression on the walled ground floor. The façade cladding made of pure mineral insulating plaster has been reinforced with wood panels and mounted onto the half-timbered walls on the top floor, as was traditionally the practice.

For sustainability reasons, copper has not been used for the sheet metal elements on the exterior of the building with the design specification instead favouring the less harmful Uginox, which likewise develops a patina and turns a dark grey colour. The external woodwork is coated with a pure, appropriately pigmented linseed oil paint. The façade has been given an authentic silicate coating, which is applied using a brush. The roof has been tiled using brown/red lozenge tiles, in keeping with the previous roof covering.