In contrast to many other of our projects, even after months of planning, we still did not know how the house would look from the outside. We designed everything from the inside out, starting with a courtyard around which the different types of day and night-time living would be organized in spatial layers. These spaces then began to penetrate – vertically and horizontally. The inner courtyard was to be both an interior and an exterior space. Conversely, we wanted to bring the outside space, that is to say the immediate surroundings – the garden with its tall trees and the view of the city in the distance, right into the house. Initially, we did not want a clearly demarcated external enclosure, rather, the aim was to turn the interior space ‘inside out’. The complete glazing of the exterior surfaces, which would create open spatial references in more or less every direction, was out of the question because the house also had to convey a certain weight and connection with the soil. Anyone standing in front of the building´s dark and smooth slate-like surface can feel its weight and volume.
However the irregular, dark colouring of the rendering also recalls something organic and soft, such as animal skin, especially in contrast with the sharp-edged glass panes of the sliding windows which form the outer protective layer of the building. These sliding glass walls, installed externally instead of internally, are actually an expression of a kind of inside-out world: the window – the classic element of the interior space – is turned outwards. We look at the house from the outside through the window, which forms the boundary of the interior space. Because of the sliding movements of the enormous panes of glass and their effect on the dark surface, the external appearance of the house is constantly changing. While each window is located at a single point in the facade, this point appears to move from side to side with the sliding sashes mirroring the daily lives of the people in the house.
The facade strategy freed us from all compositional constraints: the windows are ‘both here and there’, sometimes close to each other, sometimes further apart. This meant that we were really free in the organization of the ground plan. The structural engineering of the house is a concrete image of this plan and the organization of the interior space. As with a house of cards, the walls and facade elements also correspond to the static fields of force of the building.
Herzog & de Meuron, 1996