Tanpopo House.

This highly unusual family house in the suburbs of Tokyo combines vernacular forms with a heightened concern for materials. Stone, several types of timber and even wild flowers are used to intriguing effect.

Terunobu Fujimori is an architectural history professor at Tokyo University, specialising in nineteenth- and twentieth-century architecture with a particular interest in architectural production. When Fujimori designed his first building, the Jinchokan Moriya Historical Museum, completed in 1991, it was well regarded and widely published, but most architects assumed it was a fluke. No one expected an academic of his stature to engage further in building. Fujimori, however, found design and construction an absorbing challenge and saw an opportunity to put his theories into practice. He has since completed a second project, a house for his family in a suburb of Tokyo, shown here.

Fujimori has repeatedly emphasised that he is not a professional; yet few professionals would have the confidence to realise such a challenging concept. His partner on the house project was Yoshio Uchida, a former student of Fujimori's who had trained as an architect. Between them, drawings were treated casually and often freehanded on A4 sheets, while models were almost non-existent. Uchida translated many of these sketches into documents and attempted to develop a rational order for the parts, but just as many points were resolved at the construction site, the sawmill, or the quarry.

Fujimori holds deep admiration for the late nineteenth-century national romanticists in Japan and Northern Europe, and has named this building the 'Grass House' as a punning reference to Taut's Glass House. In Japanese, it is called the Tanpopo House, tanpopo being the Japanese word for dandelions. Planter boxes filled with flowers alternate with layers of stone to make up much of the exterior. Over a thousand wild dandelions were gathered by hand from fields at the foot of Mt Fuji and placed in the walls of this building, but the Japanese dandelion blooms only briefly, and these grace the house for less than a month of each year. At other times, sweet alyssum and other simple flowers fill the walls. The intention is to create a friendly accessibility, and the sight of dandelions enlivening the small mountain of a house is one which has caused even architects such as Arata Isozaki and Hiroshi Hara great amusement.

The teppei stone on the walls is, appropriately, a material most often used as a stepping stone in gardens. Fujimori has been developing architectural applications for its use since beginning his first building. The stone splits fiat and in consistent thicknesses (the characters which make up the word teppei are 'iron' and 'flat'), and it has a range of colours, predominantly blue-grey, but also with streaks of maroon and gold. The heavy quality it lends the house is not an illusion; the stone tablets, supported by a concrete internal core concealed beneath, weigh around 300kg per sqm. Because traditional Japanese construction rarely employs stone, Fujimori has been obliged to invent local solutions for its connection and joining, collaborating with workers at the quarry and on site.

One of the more interesting aspects of this building is the manner in which the stone is detailed. The lapped joints where tablets meet are clearly part of a vocabulary of wood construction, which both Fujimori and the labourers have used as a reference when developing strategies for the stone. Even more unusual are the points where the tablets are carved or cut to accept wood. Such details do not signify a disregard for the strength or workability of materials. Rather, they begin to suggest the veneration Fujimori has for wood, through investigating and working with the material for much of his life. This is particularly evident in treatment of the house's interior. Fujimori supervised and participated in milling the woods used throughout, bringing logs from his family's property to a sawmill where he played as a child. With Uchida, two graduate students from Tokyo University, and even a little help from this author, he directed setting the logs, cutting planks, and even how to address the problem of an eruption of mountain ants which one cut revealed. The entire process took the better part of a day, yielding timber for doors and window frames, wall, floor and ceiling, as well as finishes for the public rooms and much of the furniture built into the building.

Fujimori's facility with wood makes these interiors particularly successful. The entry and main room, which serves as a teahouse and living room, are wrapped with chestnut, mulberry, paulownia, and nara (a Japanese oak). These are expensive woods, more commonly confined to furniture. Fujimori, taking advantage of Japanese custom, used the finishes instead of furniture, considering the benefits of each. Chestnut's strength, durability, and rot-resistance are exploited in the foyer and the veranda, areas which will be more roughly treated and exposed to moisture. The cabinet where shoes are stored near the entry is of mulberry, harvested from Fujimori's family property in Nagano. Paulownia, sometimes called the Princess Tree, is a soft and easily worked wood; it is frequently used in Japan to store valuables. Fujimori used it for the interior doors, and a trunk of paulownia cut from his family property serves as the divider between public rooms and more private areas. Finally, rough planks of nara make up the floors, walls and ceilings of the main room and entry. White plaster fills the spaces between these planks, and merges with the plaster walls of the private rooms of the house. The plaster itself is unusual. Bonding agents used in plasters in Japan today often leave a shiny finish; here, Fujimori worked with the plasterer to reduce these agents and create a matte surface. Straw embedded in the plaster makes the walls look as if they are finished with Japanese washi paper, giving the finish simplicity and charm. While the plaster is very white on the first floor, in the bedroom Fujimori shares with his wife, it is a lambent yellow, recalling the glow of dandelions.

Each element in the house has been lovingly crafted. Fujimori has not only guided the making of it to an extreme degree, but has, in fact, built parts of it with his own hands, the most prominent of his pieces is certainly the set of shelves in the main room, which act as a tokonoma and are always graced with a vase. Today, Fujimori dotes on his home, as well he must, watering it several times weekly. And as each season's flowers die, he climbs the wooden brackets protruding from the walls, to plant new blooms for the next.