The ground floor of a house from the fifties is being reorganized. While retaining the existing floor plan a new volume is added, pushed against the back of the house. This results in a patio between the extension and the living space in a patio. The extension is conceived as a freestanding roof construction carried by four slender steel columns. The timber construction consists of four interlocking main beams that form a central roof light. Where the extension meets the outdoor space, it is glazed with folding joinery. In combination with the garden wall a canopy like quality is achieved in the summer. Expansion joints in the concrete floor between the colums expose the forces between the columns.