Converted Single-Family House by Lorenz Bachmann

Swiss architect Lorenz Bachmann converted a single-family home in a 1920s workers' housing estate in Winterthur for a family of four. The clients wanted a direct connection to the garden and the implementation of a large room in the small floor plan. The solution was to transform the existing roof structure, opening up the roof to create an open and spacious room with sufficient knee wall height. The architect also added a wooden terrace on the ground floor, which connects the house to the hillside garden via a wooden staircase. 

A new staircase connects the existing structure with the attic space. © Lukas Murer

The new cantilevered roof provides weather protection for the entrance area on the east side. It also offers space for storing bicycles and strollers. On the gutted ground floor, a large room opens up to the southwest onto the terrace. The bedrooms are located on the floor above. From there, a staircase made of three-layer panels, which is placed as a spatial volume in the existing stairwell, leads to the new attic space. The floating roof offers a spacious retreat. At the same time, thanks to the glazed gables, it provides an unobstructed view of the roofs of the adjacent residential buildings and the wooded slopes between Brühl and Wolfensberg.

The wraparound glazing offers unobstructed views of the landscape. © Lukas Murer

The roof rests on the existing ridge purlin and on two newly added eave purlins. Double glazing around the perimeter separates the interior from the exterior. The floor and soffit consist of three-layer panels, which lend the room a warm atmosphere despite its transparency. At the same time, they frame the view. In addition, there are floor hatches along the knee wall, under which storage space is concealed. The roof itself is equipped with a photovoltaic system that serves as a roof covering. The counter battens underneath are visible and, together with the photovoltaic panels, form a fine skin that is visually connected to the existing building by the blue color at the verge.