Tunnel Of Love
Kotaro Ide leaves no detail untended for a vacation house in Karuizawa, Japan
Benjamin Budde -- Interior Design, 10/1/2008 12:00:00 AM
For most Japanese, having a house in the mountain town of Karuizawa, 100 miles northwest of Tokyo, symbolizes attaining the good life. When the Kunimoto family asked architect Kotaro Ide to design a ground-up vacation house in the tony summer resort, he saw an opportunity to reexamine the area's unique environment and devise an updated version of the residential structures that have prevailed there over the last century.
"Karuizawa is damp," explains Ide, principal of the firm Artechnic. "I've walked into friends houses there and immediately noticed a smell that hovered on the verge of mold." Traditional Karuizawa retreats—flat, clapboard structures—were popular 100 years ago, when Japan had a strong noble class. But, as Ide is quick to point out, "They only make sense if you have staff to maintain them throughout the year." English-style houses with shingled roofs and gabled windows became the norm in the 1920's on, but they fare just as poorly in the moist environment. They dot the mountainside in various states of repair, from shiny new to moldering decay. "People visiting their house for a weekend spend a whole day cleaning and airing it out," Ide continues. "I didn't want my clients to have to deal with that kind of maintenance," he says of the Kunimotos, a married couple with two young children, who live in Tokyo year-round.
Just a cursory glance at Ide's house reveals that it's nothing like its predecessors—in Karuizawa or elsewhere, for that matter. His original design called for a structure that curved in three dimensions, like a U-shape tube. But building costs would've been prohibitively expensive. Ide simplified his concept into a more easily built form that's curved in just two dimensions, still tubular, but with no bend.
The house, which is nearly 3,600 square feet in size, looks like two enormous slices of jelly roll laid end-to-end; the rear, two-level section is larger in circumference, jutting out from behind its smaller, one-level companion. A semicircular indentation where the two pieces meet looks as if a giant bite has been taken out of the side of the architectural confection. Lining this concavity, a continuous wall of floor-to-ceiling glazing curves around a terraced wood deck with a towering fir at its center. (No trees were felled in building the house.)
The formal entrance is at the back of the house, in the two-story portion, which contains the private quarters—the master suite downstairs, three additional bedrooms and a bathroom upstairs. Also downstairs is the foyer and an airy hallway that connects to the single-level public space at the front of the house, an open-plan great room comprising the kitchen and living and dining areas. Both the master suite and the great room open onto the central circular deck.
"Design has to be accompanied by logic, function, and reason," says Ide, although this house appears quite whimsical. "Its shape came out of the idea of a cave as a natural form of shelter." And it is indeed cavelike, thanks in part to its shell of concrete, a material Ide chose specifically for its ability to handle damp conditions. The architect also raised the structure several feet off the ground to further guard against water damage. Inside, the predominant material is wood, including teak and ulin, a rich Indonesian species, selected for its visual warmth and easy upkeep. As for the surface of the concrete interior walls and ceiling, Ide treated it with insulating layers of urethane foam and vermiculite, creating an unusual finish that appears soft and spongy, but is actually hard and nubbly.
Given the house's unusual shape it's not surprising that the architect custom designed all the windows and skylights, framed in a steel-aluminum alloy, as well as all the built-in furnishings. And we're not just talking kitchen countertops (rendered in light-gray Corian) and seating (upholstered in stone-colored linen). Ide also brought his ambitious hand to the master bathroom's shiny circular tub and light-boxlike medicine cabinet; the central deck, also ulin; and even the HVAC system.
In fact, Ide saw the HVAC as integral to both client comfort and ease of maintenance. The site-specific system rests in a crawl space under the floor—"A little like an airplane," he notes—drawing in clean air through louvers under the central deck and expelling stale air through vents at the front and back of the house, away from areas where people congregate. The system keeps water pipes from freezing in winter, counteracts the chill that tends to exist in spaces with tall windows and ceilings, and avoids having to perforate the continuous curve of the concrete shell with unsightly vents. While the magical shape of this house and its no less magical woodland setting have created the sought-after refuge from city life for the Kunimoto family, Ide's refinement of comfort is an equally real feat of design.