Alnatura Working Environment is in the city of Darmstadt in Germany, and has been designed by Haas Cook Zemmrich STUDIO2050. This building is an example of new construction realized with a people-centric and sustainable design approach.
The building is the working place of 500 employees on three floors with a floor area of approximately 10,000 m2.
The building location and orientation has been determined according to the micro-climatic conditions and in order to maximise the use of natural resources available in the area. In fact, one of the main design objectives was to implement a low-tech approach for the HVAC system, in order to ensure energy efficient operation, optimal comfort conditions with limited maintenance costs. In particular, the natural ventilation potential of the area, that present a forest on the west side of the building, has been exploited. The fresh air coming from the adjacent forest is drawn into a subterranean channel by two air in-let towers and distributed through the building. In addition, the 69cm thick loam walls provide an important thermal inertia that minimises the cooling loads and allows to avoid the need of mechanical systems.
Moreover, long sides of the building are North and South facing in order to achieve optimal daylight conditions, exploiting the diffuse north light through the skylight in the atrium, avoiding high solar gains.
Another important feature of the building is the proposed façade system. It is made with rammed earth.
The rammed earth blocks were installed along the northern and southern facades to form 16 wall segments, each 12m high. This represents a geothermal wall heating system integrated into a dry loam wall. In addition, the rammed earth blocks have been locally produced, avoiding transportation costs, and are insulated with 17 cm of foam glass gravel (U-value of the wall 0.34 W/(m2 K)), obtained from Westerwald and lava gravel from the Eifel Region, and recycled earth excavated from the tunnel of the Stuttgart 21 Train Station Project.
The design of the system was challenging, and a detailed simulation activity to find the optimal dimensioning the interior volumes that play as climatic buffer during summer but can compromise the winter comfort conditions because of the cooling down. To avoid this situation, the internal walls are activated through the geothermal system that has been designed to charges the massive walls.
The roof has a wooden structure with metal covering and mineral wall insulation, with a thermal transmittance of around 0.15 W/(m2 K) and an acoustic ceiling on the inside. The heating system is based on a geothermal energy plant of 82 kW with a buffer storage of 3500 litres. Also a ges eating system is integrated, for extreme conditions, and a photovoltaic plant of 92 kWp.
For more detailed information, visit the website of Haas Cook Zemmrich STUDIO2050.