Ecology and sustainability in all respects, integration to the surrounding environment, a pleasant working environment, economy and energy efficiency – these were the investor’s requirements, Swiss wood-working company Kost AG, which the contractor had to take into account when planning the new office and administrative building in the town of Kussnacht.
Except for the concrete floor, the whole building was realized, in the full extent, from wood. The external walls and the ceilings are realized as a frame construction sheathed from the inside with three-ply boards from silver fir, with a dark facade from the same material from the inside, but pressure treated. The used three-ply fir Novatop boards, manufactured by us, have the distinction of visible wood with a fine and balanced structure without knots, and dominate the whole interior of the building. The investor’s demands for the room acoustics were accommodated with special acoustic boards on the ceilings, which were created by perforation of the visible side of the fir board in the production. The flooring from smoky oak was chosen as a contrast to the light natural interior.
The subfloor is realized from timber-concrete binding elements with the glued lamellar reinforcement as a support. In case of an earthquake or a strong wind, there is a horizontal reinforcement, stable concept with double jacketed inner walls (OSB) and laminated wooden walls at the staircase. There was a design challenge to minimize the use of steel components. The building is designed to allow the subsequent increase of one floor.
Kost-Neubau is the first industrially utilized building certified according to the Swiss standard Minergie-P-Eco. According to it, the energy used to heat office spaces must not exceed the annual limit value of 30 kW per hour per square meter, which corresponds to the consumption of three litres of heating oil. This can be achieved only through the concept of the building, which is focused on low energy consumption and it is in accordance with the technique in the building. A new construction, for example, receives hot water through the solar collectors placed on the roof and fresh outdoor air is effectively supplied to the inside thanks to a comfortable ventilating system. Numerous sensors measure environmental factors such as wind, rain, solar radiation, according to the cardinal points or different room temperatures. Based on this constantly changing data, the sensors evaluate whether the solar radiation is used as a support for heating or blinds will be cast. In warmer months, the building is cooled at night using natural ventilation; some casements open and close themselves. During cold seasons, the waste heat can be used for heating.
For a new office building of Kost company, there was used 43 m³of silver fir, 9 m³of spruce wood, 34 m³glued laminated timber, 67 m³of standing timber, 23 m³of laminated wood, 30.4 m³of wooden trellis boards, 756 m²of rough clamping plates, 753 m²of laminated wood elements, 666 m²of parquets from smoked oak and 7980 mof wooden slats. Thanks to this wood volume, there was 283 tons of CO2 permanently removed from the atmosphere, because the trees, which are equivalent to the raw wood, absorbed this amount of harmful substances to the wood through photosynthesis. This absorption of CO2 was awarded a corresponding certificate.