The shared-apartment houses in the student village Schlachtensee Berlin were designed in the mid-1970s by the architects Kraemer, Pfennig, and Sieverts (KPS). The 5-story groups of type houses are typical examples of the modest architecture of the late modern era that was enthusiastic about seriality. They were realized as extensions to the student village Schlachtensee. The two house groups were in their unrenovated 'original condition'.

The shared houses with 351 residential units represent an essential financial basis for the entire complex for the student cooperative, the sponsor of the student village Schlachtensee. This now listed complex from the 1950s by Fehling, Gogel, and Pfankuch has been extensively modernized in recent years. The flat-sharing houses with their gray-green speckled, simple perforated facades were perceived as a visual disruptive factor in this top-class modern ensemble. They should be 'upgraded' but above all modernized within a very tight budget and time frame. The house groups were only allowed to be closed for one semester season. This meant that the inside of the buildings had to be completely modernized in just 6 months. The search for the most minimal intervention was, therefore 'vitally important' for the project: After expansion, heightening or the use of the roof areas were initially discussed - a concept that was more and more strictly oriented towards the necessary crystallized out that preserves the essence of the communal houses and at the same time makes them fit and usable for new generations. An analysis of the structure of these 'organic' cell structures, which were consistently oriented towards the ideal of 'shared apartments', which could be divided and merged differently on each floor, showed that the community divisions, originally designed as 'movable' walls, never actually were moved in the 45 years of their existence - but left in their original installation location. The shared sanitary areas and communal kitchens were and will continue to serve in the future for shared apartments of six residents each. An examination of all components, the facades, windows, surfaces, doors, built-in furniture, the electrics, heating, and the sanitary facilities followed. Each measure was subjected to a strict cost-benefit analysis - with the spatial and architectural benefit being given a high priority.

At first, it was amazing how well the buildings survived their 45 years of age - they are proof that the common assumptions about life cycles are simply wrong: Not only that the buildings will hopefully far exceed their 'standard life cycle' of 60 years after the modernization - The alleged service life of max. 25 years for the building technology was exceeded by 100%. Nevertheless, our attempts to continue using at least parts of the building services - such as the heating or sewage system - were not crowned with success. The complete replacement of the building technology and the elevator systems resulted in a certain depth of intervention. The communal bathrooms have been completely redesigned and now enable simultaneous and undisturbed usability in the smallest of spaces. A considerable cost and time advantage could be achieved through their access only through the existing door openings. Instead of replacing old components with new ones, e.g. the acoustic values ​​of the interior doors were examined and found to be sufficient. The existing fire protection concept could also be updated - and the existing stairwell doors retained. Although the buildings are not listed, we used methods of monument preservation - such as the analysis of the original color versions and color concepts, which we were able to update in a radically refreshed form. The furniture from the time was also partially preserved, copied, and supplemented with new built-in furniture.
The external appearance of the building posed a particular challenge. Initially, the facade was to be renewed. A careful analysis and building physics calculation showed, however, that with a renewal of the windows as well as the insulation of the roof surface and the basement ceiling, an energetic state corresponding to the KfW funding criteria could be achieved: The colleagues in the 1970s had - shortly after the oil crisis - installed an insulating plaster system which provides a minimal but sufficient external insulation. The high-quality plaster could therefore be preserved, the new windows - in their original colors - were carefully fitted into the existing openings. The new, large-format sliding windows in the common rooms also look as if they have always been there. The plaster was cleaned and freshened up with an olive-gray-green tone. The buildings should form a unit with trees and bushes. It was important to us that the buildings are perceived as a 'background' for the white modernity of the houses by Fehling, Gogel, and Pfankuch.

Thanks to the laborious but ultimately successful search for the smallest possible intervention, the houses were able to be fully refurbished in the given time and budget. With total costs of less than 50 ‘EUR / unit, the price is less than 50% of a comparable new building (1,546 euros total costs KG 200-700 / m2). The questioning of standards, the preservation of existing elements as much as possible, the meticulous work on the details and floor plans, the updating of the existing design, and the struggle for the most durable but affordable solutions were the guarantees for this success.