Lukas Raeber
A deconstructible multifamily residence

Above a metalwork shop in Basel’s Matthäusquartier, eight new residential units rise. Made from prefabricated wood elements, the new four-story building sits atop the existing ground-level structure. On the street side, the addition matches the eave height of the neighboring property and reinterprets the adjacent roof edge as a sawtooth roof. Its shape and orientation also make it the ideal location for the building’s solar panels. On the courtyard side, the building is stepped back as required by zoning, creating a spacious balcony for each apartment.

The residential units are entered at street level, where the mix of new and existing elements feels perfectly natural. The atmosphere in this entrance area is defined by traces of the past, and by the reinforced-concrete and masonry work intrinsic to the building’s structure. From ground level, a staircase made from prefabricated wood elements leads to the warmer atmosphere of the apartments above.
Large metal panels protect the wood structure from the elements and add urban flair. The construction firm that runs the metal shop on the ground floor was extensively involved in the project – they fabricated the street-facing facade, among many other components – and their materials are visible everywhere. The simplicity of the fabrication and construction processes remains visible in the finished building, and the interplay between the different materials contributes significantly to the atmosphere of the space.

The entire addition and all of its fixtures implement the idea of “urban mining” to the greatest extent possible. This idea is based on the argument that all the resources used to build a building should be reusable, recyclable, or compostable whenever feasible. The building was designed and built with these restrictions in mind. As a result, almost all of its components are attached with screws for easy removal, rather than being glued down. In keeping with this way of thinking, the wood floors are installed with screws, the chrome-steel bathrooms are jointless, and the heating ductwork and electrical conduits are exposed.

>>> Lecture Project Efringer

Project Data

Key Figures

  • Type of use: 8 apartments above a tinsmith`s workshop
  • Site: Efringerstrasse 107, Basel
  • Floor area: 665 m2
  • Year: 2018-2022

Parties involved

  • Client: Sonja und Felix Jäggi
  • Architecture: Lukas Raeber Architekten: Flavio Thommen, Lukas Raeber
  • Structureal Engineer: Haller & Partner, Oberwil
  • HVAC: Beat Joss & Partner, Basel
  • Facade planning and execution: Jäggi Vollmer, Basel
  • Photography: Rasmus Norlander
Das Mehrfamilienhaus stuft sich zum Hof hin ab, wodurch grosszügige Terrassen für die einzelnen Wohnungen geschaffen werden
Das neue Gebäude ist ein vorfabrizierter Holzelementbau, der auf dem bestehenden Sockelgeschoss aufliegt
Die Aufstockung führt strassenseitig die Traufhöhe der Nachbarliegenschaft weiter und interpretiert den benachbarten Dachabschluss als Sheddach neu
Die einfache Bauweise und Konstruktion bleiben im fertigen Zustand sichtbar, wobei das Wechselspiel der Materialien massgeblich zur räumlichen Atmosphäre beiträgt
Die gesamte Aufstockung sowie sämtliche Einbauten folgen bestmöglich der Idee von «Urban Mining»
Es wurden keine Bauteile fest mit dem Untergrund verklebt, sondern geschraubt und demontierbar ausgebildet wie hier bei den Chromstahlbädern
Spuren der Vergangenheit prägen die Atmosphäre im Eingangsbereich
Schnitt und Regelgrundriss