Villa A | Karuizawa, Nagano, Japan | Satoshi Okada Architects

Villa A is designed for a vacation house in the town of Karuizawa at the east end of Nagano Prefecture.
It is about 1000 meters above sea level, historically one of the most popular summer resorts within easy reach from Tokyo.
The quasi triangular site is sloping down towards the south, from which a beautiful nature view can be appreciated over a valley to mountain ridges.
It is plenty of old and tall deciduous trees above and overall bamboo grasses below; however, a neighbor house is close to the east border, which is the last unfavorable artificial element seen from the site.
According to regulations in the district, at least 1/5 gradient is required to any kind of roof, building must be set at least 10 meters off from public road borders, and the building should be less than two-story.
The villa is composed of two portions. One is the semi-underground part for private rooms - guest room, bedrooms, library, and a bathroom with laundry - made of reinforced concrete structure, open to the south side terrain.
The spindle plan shape is the most suitable for existing contour lines geographically as well as for the posture of bearing wall against the horizontal load from the earth.
The other is an over-ground building for the public realm - living, dining, and kitchen. It is consisted of steel structure totally surrounded by transparent glass walls. Because garage and entrance are placed under ground on a ridge line, the latter one looks independently standing after the short tunnel in-between.
A bent roof, the most particular element in this villa, was intended to shelter the upper building with an image of a bird's wing fully extended for brooding over a nest. It also functions to blind softly the neighbor building on the east.
Schematically, it was designed as follows: first to bend a plate two dimensionally, second to incline at 1/5 gradient; and at last to cut-out the plate for covering the building.
Structurally, the roof is made of sandwiched panels of Corten steel plate with lattice ribs inside, and it is only 15 cm thick in total.
In this project, I try to integrate architecture and landscape into designing a whole environment in cooperation with Paul Smither, British horticulturist, active in Japan today......more