Max Kißler, Olaf Rohl, Dan Zoubek, Bauwens
The new office building on Darwinstraße is the first step in the conversion of a former power plant site in Berlin-Charlottenburg, combining new working environments with ecological and social added value for the urban community. The building, with 12,000 m² of office space for up to 1,000 workplaces, is being expanded to include a 2,200 m² roof park that extends from the ground floor to a height of 30 meters. The cascading gardens invite visitors to ascend – as a place of relaxation and informal encounters. On each level, the office spaces can extend into the outdoor area through large sliding doors – indoor and outdoor spaces flow into one another. To implement the conceptual design idea, all specialist planners had to work closely together to ensure that all biological and technical requirements were met. The greenery is not merely decorative, but a structural component of the building. The gently modeled transitions between the floors, filled with topsoil, form a continuous, landscaped park. The ascent along generous plantings with a variety of grasses, perennials, shrubs, and trees leads to the square above the Spree with a panoramic view of the city. The redesign for redensification redefines the balance between artifact and nature and aims to improve the quality of life in the city. It weaves functionality, sensuality, and biodiversity into urban vitality. The trees prepared in the nurseries were photographed and modeled as digital twins by the A.R.T. office (structural engineering) in order to perform future wind simulations using growth calculations. In order to plant 22 large trees at a height of 30 m on the roof, new structural solutions were developed for anchoring the root balls. Steel chairs for large trees Round planting chairs made of hot-dip galvanized steel were mounted directly onto the reinforced concrete ceiling, making them part of the supporting structure. The planting chairs, with diameters of 180 and 240 cm, were raised to the required height using 160 HEB support feet, depending on their location. The root balls were fixed in place using the eight spikes (Ø 20 mm, 250 mm long) on the planting chairs and secured additionally with tension straps. As they continue to grow, the roots anchor themselves in the open spaces, creating a structural-botanical unit of plant and construction. Thanks to these precautions, a substrate thickness of 140 cm, and retention boxes with capillary mats, the 22 trees have been thriving ever since. They cool, bind CO2, improve the microclimate, and make an important contribution to biodiversity and climate adaptation in the city.
Grüntuch Ernst Architekten / capattistaubach urbane Landschaften
