Garage today, apartment building tomorrow. Parkhaus Wendlingen and its path to total adaptability

Design solution

The uniqueness of the Holzparkhaus Wendlingen project lies primarily in its structural design. While reinforced concrete is the standard for such buildings, timber dominates here. This is used in the form of a prefabricated glulam system, where the columns and bays are made of glulam timber (BHS) to provide the necessary load-bearing capacity, while the ceilings are made of cross-laminated timber (CLT) panels. Concrete was used only in the necessary places for structural and fire safety reasons: for the two reinforcing communication cores and the central access ramp.

A major operational benefit is the absence of bollards in the parking lanes. The wooden spans have a span of up to 16 metres, which completely frees up handling space for the driver. However, a major challenge was to protect the wooden structure of the ceilings from water and salt stress, which is solved by applying a durable layer of cast asphalt.

Circularity with regard to the city

A key aspect of the project is its sustainable vision and the real application of circularity principles. Approximately 2,400 cubic metres of certified timber was used for the construction, which has a major impact on the carbon footprint calculation as the structure itself holds almost 2,000 tonnes of CO₂. With regard to circularity, the authors then avoided the use of any composite materials and almost all joints are made mechanically without gluing. This guarantees easy disassembly and reuse of all materials.

The organic shape of the building responds to the limited possibilities of the plot sandwiched between the railway and a busy road. The location of the building strategically corresponds to the function of the P+R terminal, which relieves the congested city centre by encouraging drivers to switch to rail. It has a capacity of 349 cars and facilities for 150 bicycles.

The outer cladding is designed with respect to the immediate surroundings, with the northern façade towards the residential development consisting of profiled translucent glazing that acts as a noise barrier. In contrast, the southern façade is completely open and covered with greenery. This openness is essential for the fire safety solution, which, thanks to this lateral ventilation, can dispense with the costly installation of air conditioning and sprinkler systems.

The vegetated façade and roof were designed by the Planstatt Senner studio, which conceived the building in this respect based on the concept of a mushroom city – especially in terms of efficient rainwater management in the event of heavy rainfall. The roofs and vegetation ensure that the water is slowly drained, absorbed and also has a positive effect on the microclimate of the surrounding area.

Vision of the redevelopment

The authors addressed the question of the future transformation of urban mobility not only through the reuse of materials, but above all through the possibility of complete adaptability of the building as a whole. From the beginning, the project was designed with parameters for residential or office buildings. Instead of the standard heights used for parking structures, the building has a floor clearance of 2.35 metres, with up to 3.40 metres between the bays, which meets local standards for living quarters. At the same time, the central concrete ramp is structurally completely independent and can be removed in the event of a conversion, turning the resulting space into the atrium of the new house.

The project in Wendlingen thus sets a new standard for the design of public buildings, where sustainability is not only based on the materials used, but its principles are woven into the very design and vision of the future life and functioning of buildings. In a sense, the architects’ response to the climate crisis is a willingness to facilitate as much as possible the path to adaptation and total transformation of their own work, the concept of which changes our current view of the parameters of architecture.