The gallery and studios at Brunnenstraße 9 are built on the foundations of a ruin, which was the result of a bad investment in the 1990s. This made the site unattractive to corporate investors who were buying empty lots at the time and enabled architect Arno Brandlhuber, both investor and builder, to purchase the site for the running costs minus the demolition expenses. When the plot was purchased in 2007, only a couple of walls and parts of the basement ceiling remained, alongside the elevator shaft and an entrance passage. Instead of removing this original structure, it was included and developed further in the new design. At the time, Berlin’s Senate Department for Urban Development was promoting a Critical Reconstruction agenda, a redesign approach to restore the historic urban tissue. Instead of interpreting Critical Reconstruction as regressive, Brunnenstrasse 9 made use of the idea of referencing the site’s context to create a new typology for working and living. The basic volume is defined by the eave heights of the two adjacent buildings, with the attic floor shaped accordingly to compromise with the neighbors behind the rear courtyard, ensuring that light reaches their buildings.
The continuation of the adjacent building heights into Brunnenstrasse 9 results in a 30 centimeter difference between the two floor levels. This 30 centimeter step occurs on every story, creating a natural division of space with different height zones apt for various uses. The initially unroofed basement has become a double height room, visible from the street. If desired, this single space can easily be divided into two by inserting a ceiling, using the visible anchor bolts already set in the reinforcement. The concrete core, reduced to a minimum, houses the bathrooms and the elevator. It directly connects the different units to the street level via an entrance located in the public passageway. Apart from this central core, there is no other physical connection between the single units. The only way to circulate between them is either through elevator access or the external staircase attached to the rear facade, like at 0019 Kölner Brett . This exterior circulation layer is offset five meters from the back facade in accordance with the building code and fire regulations. The need for an interior stair is eliminated by shifting the staircase outside, which permits maximum spatial efficiency and complete independence for the users. The platforms connecting the exterior staircase also function well as terraces and public space for the residents. As the tram wires prevent firefighters from using extendible ladders on the street side, a second entrance had to be installed at the rear. In order to comply with regulations for the second fire escape—via the windows—the courtyard ground was raised 72 centimeters on one side and 36 centimeters on the other to match the maximum length of the fire brigade’s eight-meter ladder.
This methodology of understanding, using and reacting to the given rules and building code parameters also shaped the facade. The street side, facing the heavily trafficked Brunnenstraße, is given a closed quality. To allow light to enter the space, every story has a fixed glazed part, whose length derives from the maximum liftable weight for an average crane, while the rest is cladded in translucent polycarbonate panels. The polycarbonate has a specific sun protection layer, which generates different colors in the course of the day. Small ventilation flaps set on the facade side provide cross-ventilation for the interior spaces. The rear wall facing onto the courtyard is completely glazed. Floor-to-ceiling sliding doors allow the users to open half the facade and look out into the courtyard. All facade elements rest on a robust metal substructure of L-brackets, which allows for future changes to the facade, following the same logic of flexibility and adaptability employed on the inside. The concrete slabs were built at the same time as the shell. All interior walls are in cast concrete, without any preconceived system for the formwork and pattern. All the walls and floors were ready by the time the structural work was completed, and were treated afterwards. The electrical system is concealed in ducts embedded in the concrete while the heating pipes are exposed, with no insulation, in order to heat the space. This concrete platform enables users to adapt the rooms to their specific needs while keeping costs to a minimum and ensuring the affordability of the space. The only pre-installed elements are the mechanical connections and oak planks along the street facade, used as a substructure for the polycarbonate elements on one side, while on the other side, they can be used as benches, desks, or shelves.