B4 House Conversion and Extension by weberbrunner architekten ag

The B4 House Conversion and Extension is a thoughtful restoration and expansion of a single-family home in Witikon, one of Zürich’s oldest neighborhoods. Perched on a south-facing panoramic slope, the property enjoys sweeping views of the city and surrounding landscapes. Originally built in 1927, the compact cubic house reflects the Heimatstil and neoclassical architectural styles, which have been carefully preserved and complemented in the renovation.

Design and Architectural Approach

The project involved restoring, converting, and extending the original building, adding both ground and basement floor extensions. The design emphasizes a sensitive integration of historic architecture with modern living standards while enhancing natural light and spatial flow.

• Top Floor Enhancements: Enlarged skylights and opened attic spaces improve daylighting and create airy interiors.
• Ground Floor Extension: A spacious kitchen and dining area provide modern functionality.
• Basement Studio: The lower floor features a versatile studio connected to the garden via an internal staircase, promoting seamless indoor-outdoor living.

Materiality and Construction

The extension is designed as a two-story steel skeleton on a reinforced concrete base, combining industrial precision with elegance. Key features include:

• Filigree Window Systems: Slim-profile, outward-opening casements provide transparency and a modern aesthetic.
• Wraparound Kitchen Façade: Evokes a summer house, enhancing openness and connection to the garden.
• Natural Stone Patio: Patio doors lead directly to an outdoor platform, integrating indoor and outdoor spaces.

The original historic fabric has been carefully preserved, upgraded, and supplemented to suit contemporary lifestyles, conserving resources and maintaining the building's timeless character.

All Photographs are works of Beat Bühler