By locating this cubic extension on the shaded side of the existing 1930s house, it was possible to retain the best parts of the site for garden use. The main areas of glazing in the largely closed new volume overlook the garden and allow an outdoor extension of the living space. The new and existing internal spaces can be opened to each other to whatever degree is required. The low-energy extension has a timber-framed structure, which facilitated an almost complete prefabrication of the building. It is clad with blue-black fibre-cement sheets, the joints of which articulate the facades into a geometric pattern. The grey windows are set flush with the facade. The bedroom windows overlooked from other buildings are screened by fixed wood louvres.