Situated north-west of Tokyo on the edge of one of Japan’s national parks, this weekend house is a two-hour car drive from the capital. The site commands a view of Mount Asama (8,400 feet) – hence the name “Asama House”. In response to the client’s wish to lead a simple life in the midst of nature, the architects integrated this small structure inconspicuously into a grove of Japanese oak trees. Like the dark-brown coloration of the building, the form of the pitched roof with a flatter central section is typical of houses in this region, which is subject to heavy snowfall. Internally, there is a dominant main space that accommodates all common domestic activities. The open spatial quality of the house is nevertheless subtly articulated by the wall slabs at the level of the roof structure. The windows in each of the enclosing planes of the roof allow fine views out to the peaceful surroundings – to the grove of trees and the sky. The windows also stimulate an awareness of the movement of the sun during the course of the day – from the opening in the wall of the east-facing sleeping recess, via the zenith light over the dining area and the large south-facing window in the living room, to the veranda on the western side of the building. Depending on the position of the sun, the ­skylights also highlight different compartments within the roof space. In keeping with the simple character of the house, the closely spaced load-bearing wall posts were left visible. The roof structure, in contrast, is clad with white-painted plasterboard and spans the living space without ­intermediate supporting columns. Externally, the walls are clad with horizontal cedar lapped boarding painted dark brown. This is echoed by the dark-brown sheet-metal roof covering with flat-welted seams.