BACK TO NATURE.

This weekend house in a dense Japanese forest embodies a poetically rustic communion with nature and the seasons.

Two young architects, Takayuki Murakami and his American partner Mira A. Locher, who spent their formative years working in Tokyo under the architect Kinya Maruyama at Team Zoo's Atelier Mobile, have recently established a practice of their own. Their first project is a weekend house in Nasu, Japan. A resort area north of Tokyo where the Emperor has his summer palace, Nasu is known for its mountainous terrain.

Continuing Team Zoo's philosophy of seeking architectural solutions through teamwork, they also followed another principle of not separating the architecture from the landscape. Seeing the site for the first time -- a steep slope covered with deciduous trees near a mountain top -- they decided to configure the house within a grove of trees without destroying any of them. The challenge was to design a mountain retreat that felt like it had simply grown out of the site.

After sketching the trees onto the plan, the form of the house emerged. Several trees, mainly oak, maple and silver birch, are incorporated in the design. Two grow up through a raised deck; for others, the rooftops are notched to allow for the sway of trunks and future growth. A lone mountain cherry at the centre is encased in an inner courtyard. Glassed in and open to the sky, this courtyard around which the two-storey house revolves can be perceived as a still life or a scroll of the changing seasons; from cherry blossoms and sprigs of mountain azalea in spring to snow drifts in winter.

In summer, the thick tree canopy acts as a cooling device, providing deep shade. In winter, the south-facing house is open to angled sunlight in all rooms through large double-glazed windows as well as through clerestoreys under the roof line. All these windows and openings are aligned so breezes circulate freely through the spaces.

Exterior walls of rustic cedar shingles are insulated with an air space to protect the interior from extremes of heat and cold. As the shingles weather to a deep grey, the house appears from a distance to disappear into the forest. Under the staggered rooftops of a silvery metal that dip down into the courtyard, the eaves are plastered pink and inlaid with Mexican tiles.

The steep site contours gave the architects the opportunity to design the interior on two levels, with private bedrooms and bath along a corridor on the upper level, and the open public space, combining kitchen, dining and living areas, below. A staircase on either side of the courtyard accomplishes the level change. While the house is compact and efficient in the Japanese style, nothing has been spared for comfort. Within the voids of the structure, ample cedar storage spaces have been inserted.

While both master bedroom and guest room at either end are furnished with Western-style beds, natural light is regulated by traditional shoji screens and the electric light shaded with paper lanterns made famous by the artist Isamu Noguchi. A built-in desk and bookcase make a private preserve of the master bedroom away from the conviviality of weekend guests. Wood brings a warmth to all these spaces.

Throughout the corridors and stairwells into the main living area, Murakami & Locher have treated the walls with the rough surface of ochre plaster mixed with straw and sand reminiscent of mud or earthen wall construction in ancient Japanese structures, notably in teahouse architecture, Its buttery glow blends with the veneer plywood wainscoting and the rich cherry floors below. The cedar battens that cover the joints in the wainscoting are typical of the way in which the architects create elegant ornamentation out of practical detail. Earth architecture has been a focus of their recent travels to India and China, and the bulbous shape of the chimney for the fireplace, built first in a wooden frame and then rendered, is influenced by the forms of adobe dwellings.

To incorporate the kitchen into the living area represents an innovation for a Japanese house, but here the rough hewn logs and wooden slabs for the eating counter and high stools, designed by Takayuki Murakami himself, introduce a sculptural element that adds to the practical rusticity of the interior.

A further incline in the site made it possible to design a sunken living room with a low built-in bench around the perimeter where family and friends congregate around the fireplace after meals. Windows are brought down to the level of the seating to take advantage of views to the south over the tree tops to the mountains. Upon entering the house into the genkan or vestibule, a very small deep-set window in an interior wall overlooks this living area for a preview of the inner spaces. At the centre always is the courtyard, a visual reminder of the seasons contained within the house just as the house itself is contained within the natural grove of trees in a perfect union of landscape and architecture.