Kastanienallee 12: Prototyping Regenerative Renovation

The K12 (Kastanienallee 12) project explores socially and ecologically responsible ways to renovate a Gründerzeit-era building ensemble on Kastanienallee in the densely built and gentrified district of Prenzlauer Berg in Berlin. The buildings require comprehensive modernisation that balances sustainability, affordability, and heritage preservation.

The project investigates how climate-friendly and socially equitable renovation methods can be implemented and scaled. It aims to define a new minimum standard for reduced resource use, CO₂ emissions, and affordability in existing buildings.

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The Hirschhof in Prenzlauer Berg was an outpost of alternative culture in 1980s East Germany. Reunification brought privatisation, and privatisation brought demolition. Only four apartment buildings survived. Today, the dense courtyards of Kastanienallee 12, scattered with graffiti, art objects and improvised furniture, still echo the informal spaces of freedom of the Wendezeit. Tiny flats, stairwell WCs, coal heaters and kitchen-baths stand as rare traces of Prenzlauer Berg's working-class past.

Kastanienallee 12 features a representative front building with a Beletage, bay windows, high ceilings, parquet floors and stucco detailing – followed by a sequence of three identical rear buildings with narrow courtyards. These contain small single-aspect apartments with two rooms each, low ceilings, simple Rabitz partition walls, timber floorboards as well as shared toilets located on the stair landings.

In 2022, K12 was rescued from forced auction by the Edith Maryon Foundation and the Selbstbau eG cooperative. Since the GDR times, no renovation measures have taken place. A large part of the ensemble is its original state and now in urgent need of refurbishment.
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Together with Hütten & Paläste and the inhabitants of K12, Bauhaus Earth will be researching, prototyping and monitoring minimally invasive, circular strategies and bio-based materials for insulation and retrofitting. We will develop different practical solutions using straw, hemp and paludi materials, in combination with light earth and earth plaster. Our goal: a transferable model for urban development that is socially equitable, climate-conscious and respectful of listed buildings.