This architect's home is his laboratory

``We started our home in the Carmel Valley in 1978, moved into it in 1980, and hope to complete it in 1987,'' says George Brook-Kothlow, a California architect who has thoroughly enjoyed watching the house he designed for his family evolve over the years. Even unfinished, the architect claims that the house has always been comfortable and complete enough to be workable. Progress has been slow, moving each year only as finances would allow. Adjustments have obviously been necessary, he explains, but the ongoing sense of achievement has been enjoyable.

The house has also served as a laboratory for his general architectural practice in Carmel. Ideas have been devised and refined, particularly in the realm of solar energy application and the relationships of function to site.

``I also love living in transition,'' his wife, Jennifer, joins in brightly, although many spouses might not be so equable about watching a dwelling emerge so slowly.

``The lovely thing,'' she goes on, ``is that it is like living in the heart of nature. With all its glass, the house is completely oriented to the outdoors. And our site is beautiful! We look into a mountain on one side and down the Carmel valley toward the ocean 10 miles away on the other. The house nestles into the landscape as if it had somehow grown there. It is a contemporary house made for California living, particularly for people like us who love animals and lots of outdoor activities, including skiing and backpacking. We like the idea of being able to move easily from inside to outside.''

Mrs. Brook-Kothlow is a potter and has her own studio, separate from the house, with a newly completed large kiln for firing her big pots. She plans to throw ceramic sinks for the two and a half baths in their home.

``George is the thinker and the planner, and does the drawings,'' she says, ``but I love to work with my hands.'' She even assigned herself to the initial construction crew and wrapped pipes, shoveled sand, and handled many other odd jobs.

As for furnishings, the architect explains that in this type of house he normally likes the clean, uncluttered effect of some built-in seating and storage pieces. These will come later. In the meantime, the family enjoys the nice ``fit'' of a collection of antiques that Jennifer inherited from her father. Included are captain's chairs, a massive old English seaman's chest, a Jacobean chest, a French desk, an antique Chinese chair, and a kilim carpet from the Middle East.

Would they have anything different if they were planning the house again?

``Yes,'' says Mrs. Brook-Kothlow, ``I would have a walk-in pantry, and a mud room where we could hang up outdoor clothes and take off and store sports gear. And I'd probably put the oven in the center island of the kitchen, where it would be more practical, instead of on a side wall where we have it.

``But these things are minor. I love the house and it seems restful and consistent to me to have all redwood inside and out, and no paint or plaster to be concerned about.''

College-age daughters Ingrid and Marit also feel it has been fun to live in a growing house, and in such an unusual one as well.

Architectural photographer Philip Molten, who has visited the house from time to time at its various stages, terms it ``idiosyncratic, but the work of a meticulous architect/craftsman who is methodically working out a long-range plan with a remarkable sparseness of materials - glass and recycled redwood.''

All floors are polished concrete slabs which absorb solar heat through large expanses of south-facing windows - heat that is later released at night as part of the passive solar system. The unheated solarium-greenhouse also acts as a passive solar heat collector.

The house itself is flat-roofed, airy, and pavilion-like. It has 1,600 square feet of heated space, and 3,000 square feet of roof area, including the 64-foot-long glazed solarium-greenhouse that connects the three primary elements of the house. One element contains the living-dining-kitchen-study area and utility room. The second contains two bedrooms and a bath for the daughters, and the third contains the master bedroom, dressing room, and bath. Outside terraces further extend the interior sense of space.

The use of recycled redwood presents a fascinating aspect of the house. The architect purchased a complete railroad bridge trestle that once spanned the Russian River north of San Francisco and had the wood trucked down to Carmel in 13 trailer-truckloads.

``These timbers,'' he explains, ``are so weathered and seasoned that they have shrunk their limit, and are relatively light because they have cured and dried out over the years and lost a lot of their weight. What they have retained is their strength and stability and the character and beautiful marks that come with long use. And their scale can at times be heroic.''

This one bridge purchase provided enough timber for at least eight houses. Brook-Kothlow, along with other California architects, has discovered the charm of using recycled redwood for framing, siding, and interior paneling of contemporary West Coast houses. Their interest has created a market for old redwood structures, including bridges, storage tanks for water and wine, and even parts of the aqueduct system that for 50 years carried water from the high Sierras down to San Francisco.

Brook-Kothlow grew up in Minnesota, studied at the University of Colorado, and came to Belvedere, Calif., to begin his career with architect Warren Callister. He arrived in Carmel to supervise one job but remained to live and to establish his own practice.

``This is an area that is open and receptive to new ideas,'' he says - and one that is full of dramatic sites on which to build great houses. The Big Sur coastline is dotted with Brook-Kothlow's coastal houses, as is the scenic 17-Mile Drive north of the town.

The Carmel architect says he strives toward a style that might be called ``understated, timeless California contemporary.'' The design expression of all his houses is mainly structural and organic, and he prefers to use such materials as timber, stone, and reinforced concrete. He terms himself an environmental architect because he tries to relate all his houses to their sites from an environmental viewpoint.