The Altmark housing cooperative (WBGA) is not demolishing an empty prefabricated block in Stendal. It is taking the building apart from the top down. Eighty vacant flats on Albrecht-Dürer-Strasse are to become 30 homes, each with its own entrance and its own garden.
The project is called "Einfamilienhaus-Haus", roughly a single-family house within a house, and is thought to be the first of its kind in Germany. It addresses a contradiction familiar to many eastern German towns. Flats stand empty while land for detached houses runs short. In Stendal alone, more than 6,000 flats were demolished between 2000 and 2013, including the entire district of Stendal-Süd, the Austrian daily Der Standard reports.
Two coincidences brought the Berlin architect Jurek Brüggen to the problem. A train delay stranded him in the town overnight, and he saw row after row of WBS 70 blocks. Shortly afterwards he read in the local paper Volksstimme that building land was scarce. "It is absurd to tear everything down and seal the ground, only to build a handful of detached houses in the end," Brüggen told the trade magazine Architektur Aktuell.
His answer inverts the logic of the prefab. These blocks were assembled from precast concrete parts, from the bottom upwards. Now the building is being partly stripped from the top, which creates terraced levels. The removed floor slabs are not going into rubble. They serve as an extra load-bearing layer and make gardens possible on the roofs of the homes below.
A structure with no reserves
The engineering is demanding. Prefabricated blocks carry virtually no spare load capacity, the Berlin engineering firm EiSat told the trade service BauNetz. Heavy floor coverings therefore have to give way to lighter ones. Ring anchors take over the load-bearing role of the removed slabs. Two vertical cuts run right through the block, which gives the wind more purchase. The old stairwells are being braced with an additional wall.
Those cuts open up the building. Brüggen describes them as a vertical extension of the neighbourhood street, with front gardens and open squares outside the doors. Nobody should have to pass through a stairwell to reach their home. The houses range from 32 to 159 square metres and have between one and six rooms. In each one a ceiling slab is removed to create a double-height room.
The cooperative set the architects one condition. Net cold rents below ten euros per square metre must remain achievable. Lars Schirmer, a board member of the WBGA, stays sober about it: "It will always be a compromise."
The stripping work was paid for out of urban development funding that normally finances demolition. It is largely complete, but the detailed construction planning has not yet been commissioned. To fund the conversion, the WBGA is looking for a new umbrella cooperative and an investor. It also wants to preserve two more prefabricated blocks in the Stendal-Stadtsee district.