House in Iruma

House in Iruma | Japan | 2016
[aoyagi design]

The site is in a residential area in the suburbs, and the house is for a couple and their child. The composition is that of an introspective triangular attic space sitting on an open first floor of wooden and steel construction.

The triangular prism is formed by a truss of CLT panels. The 90 mm panel thickness, though a response to exterior wind pressure, is not only structurally functional but also gives beauty. The rich texture of wood makes it unnecessary to install further interior finishes. The structure also eliminates the need for insulation due to the considerable thickness of the panels.

Compared to the first floor which contains all the functions for daily life the attic has no fixed purpose. It also has a different sense of scale, with a ceiling height of 7 meters. The smooth surfaces conceal the structure and emphasize the triangular form.

Another point of contrast is light and shadow. The first floor is bathed in natural light, while the 7 meter high attic space is engulfed in shadow. Through the atrium, the attic’s darkness extends to the 1st floor, intermingling with its natural light. This merging of light and shadow expands the space and blurs the boundaries of the quality of attic vs living. Text description by the architects.