The office rundzwei Architekten has realised an unusual private home called the “corkscrew house.” Below ground, a robust base of rammed concrete defines the lower living spaces and a sunken outdoor pool, while above, carefully stacked split-levels—accessed via a central, atrium-like staircase—provide over 320 m² of flexible living area. A monolithic cork envelope clads both the facades and the roof, ensuring excellent insulation, acoustic performance, and a distinctly organic look.
A base made from rammed concrete
This centuries-old construction technique involves layering and manually compacting concrete in formwork, yielding open, porous surfaces. The architects intended the lower portion of the house to appear as though it was “excavated” from the ground, giving the building a grounded and tactile character. The subterranean areas include a bedroom and the main living-kitchen zone, both benefiting from the thermal mass of the rammed concrete and direct access to the outdoor pool. The same rammed concrete walls extend around the elongated pool, providing privacy from neighbours and linking interior and exterior spaces.
Maximising usable area by lowering floors and introducing multi split-levels
Although local planning regulations restrict the above-ground footprint to 100 m², rundzwei Architekten maximised the total floor area by lowering part of the residence below grade and stacking the upper storeys in multiple split-levels. These stepped half-levels spiral around the central stair, creating an open, interconnected interior that exceeds 320 m² in total. Structurally, the house is divided into two distinct zones: a rammed concrete base below and a timber-framed upper portion. Large glazed openings on the ground floor bring in abundant daylight, while the multi-level arrangement ensures that no single level feels isolated or cramped.
Cork panels on facade and roof
Above ground, the walls and roof are wrapped in cork panels sourced from Portuguese manufacturers who repurpose granulated cork waste from wine-stopper production. Learn more about this through Archello's dedicated detail article: Detail: Cork Facade of Corkscrew House, Berlin.
Under heat and pressure, the material’s natural resins bind the granules, forming durable, lightweight sheets with no added chemicals. This results in a weather- and mold-resistant cladding that also lends the residence its sculptural, monolithic quality. Only the necessary openings and the rooftop solar panels interrupt the uniform cork surfaces, accentuating the dwelling’s cohesive form.
Cork contributes significantly to the home’s energy efficiency, thanks to its strong thermal-insulation properties. It also offers excellent acoustic performance, an important factor given the site’s proximity to the former Tegel Airport flight path and the client’s desire to reduce the sound of rainfall on the exterior. By cushioning ambient noise, cork helps maintain a comfortable indoor environment and underscores the project’s commitment to sustainability and occupant well-being.
Natural construction materials, natural ventilation
Throughout the design, the architects avoided chemical adhesives and conventional foams, preferring materials like wood fibre and cellulose insulation to complement the cork cladding. Timber elements, gypsum-fiber boards, and permeable paints regulate humidity and ensure a pleasant indoor climate without the need for active ventilation systems. Heating demand is largely met by a stratified heat storage mechanism, supplemented by solar panels integrated into the cork roof. The result is a low-energy residence that can operate almost self-sufficiently.
Flexible living
Originally designed for three occupants, the house can adapt to changing needs or an expanded household in the future. A bedroom and primary living area occupy the lower level alongside the kitchen, with direct access to the sunken courtyard and pool. Upper floors are subdivided into smaller rooms around the central stair. These spaces can be joined or separated into potential studio apartments, as the façade is prepared to accommodate a second entrance if desired. This flexibility allows the residence to evolve over time without compromising its architectural or environmental aspirations.
