DAVID DEUTSCH stood on the patio of his house, pointing out the almost invisible solar collectors on the roof. "I like the house because it's a nice house first and a solar house second."

David and Stephanie Deutsch's new house is almost a catalogue of passive and active solar devices. The house has not only solar-heated water, but solar space heating - and solar air conditioning.

From the street, the 26-foot wide house looks ordinary. There's no visible evidence of the house's link with the sun. The slanted, almost mansard roof in front has no solar hardware on it. Two low pierced brick walls enclose the front garden and a narrow entry terrace. Lights over each front window and sunburst metal window protectors remind you that on Capitol Hill people believe in security. The rest of the block isn't remodeled yet, but the derelict house next door, with windows broken and paint peeling, is up for sale at about $80,000. The site is 11 blocks from the Capitol.

Walking trhough the house with the Deutsches, you soon learn that Thomas Simmons, the architect, tucked in every thing he could think of to make the house easy to cool and heat. He had some help from the house itself, a 1920's standard design, with almost solid east-west walls. Only a tiny window is on the east side. All other windows are on the south and north. The south sun, being the source of most solar heat and the easiest to shade, is the most desirable for large window areas. The rear of this house faces south and the garden. The front and north side has the five original windows, now double-glazed and protected with shutters against winter cold.

"I told the Deutsches that the house was a natural for solar heat," said Simmons.

Deutsch said, "I guess we were sort of naive." He is a television director with WETA. His wife is a volunteer reader for records for the blind. "We's never thought about a solar heated house. And we were well into the design before we talked about it. Simmons told us about Bob Cotton, an engineer who specialized in heating and cooling. [Sadly, Cotton died before the house was completed.] He agreed, the house was perfect for solar heat. After thinking about it, Stephanie and I were really enthusiastic."

A new development in solar collectors, a mirrored tube that doesn't have to sit up as high on the roof, made it possible to almost hide the collectors even though the back roof is nearly flat. The collector is made locally by KTA, of Rockville. The tube also is considered more efficent than older designs because it heats the water (which runs through its closed system) to a higher degree. Paradoxically, solar cooling needs hotter hot water.

Cotton advised them to use 400 square feet of collectors.He thought it should save them about half their heating bill and 60 percent of the cooling bill. The Deutsches moved into the house during the February snow storm. ("David was finishing a big documentary and I had to do it by myself," noted Stephanie Deutsch, for the record.) But they aren't sure yet what their yearly bill will be.

The house has a backup furnace, Arka Solaire, which might be called a kind of gas heat pump, to fill in on dark days. A 1,300-gallon tank, insulated like a Thermos bottle, is buried beneath the basement floor to store hot water. Deutsch figures the solar installation cost them between $15,000 and $20,000, about twice the cost of a conventional heating/air conditioning system. But as the price of energy seems to double every time you turn on a switch they expect it to pay for itself. Lou D. Keller was the plumber for the solar installation as well as the rest of the plumbing. Sam Garrison was the air-conditioning contractor.

Simmons perhaps is proudest of the house's passive solar devices. "I think the day has come when we have to use architecture to solve the energy shortage," he said. The house is full of such devices, most of them the sort the house might have had in it originally.

The doors all have transoms over them, so they can be opened and closed to control air.

Deutsch himself suggested the ceiling fans. Two are in the living room and another upstairs. He was pleased to find that the ceiling fans also work in winter to send the hot air back down again.

Awnings protect the large sliding glass doors in the master suite and the clerestory windows on the top floor. In the winter, they fold back to let in more sun. Cotton suggested them as an alternative to tinted glass. Over the kitchen's south glass wall is an open overhang that will eventually be covered with shading vines.All the major glass walls face south. All have at least a 2 1/2 foot shading device to keep out the summer sun.

You come in the front door to a pleasant hall with a natural oak staircase. The doors are paneled, a difficult (and expensive, each cost $200- $250) job by Tart Lumber Co. To the left is a small library with a fireplace and bookshelves. So far, nothing out of the ordinary. You walk through a low arch, with display shelves on each side. When you come into the living room you see the big wall of sliding glass doors with a long window over it. The living room is on two levels, united by an S-shaped built-in sofa curving between the floors. Deutsch had Carl Friedlander, a carpenter versed in intricate work, make a narrow counter topped with formica for drinks across the back of the couch. Another arch (supporting the second floor) defines the steps.

The glass, the white walls the built-in furniture and the bare wood floors give a clean contemporary look to the room. The effect is softened by the sofa's orange cushions, an old rolltop desk and a wonderful clock with a moving sailing ship. A narrow wood-topped dining table, bentwood chairs and a cabinet are the only other furniture in the room.

To one side of the glass wall is a slanted white wall with a pass-through. Behind is the kitchen, a triangular room that cuts across the back of the house. The kitchen has an air of importance, as well it should since Stephanie Deutsch learned much at her mother's kitchen counter. The stove was taken apart and set into a tiled surround by carpenter David Arthur. The floor is octagonal Mexican Tile. A fine table by John Huzway of Capitol Hill Kitchens provides a pleasant place to eat against the 8-foot wide sliding glass doors.

The outside is as elaborately designed as the inside. Brick covers most of the patio, with a curving planting bed along the edges to soften the handsome brick walls. Halfway back is a pergola, a wonderful redwood open roof structure, architecturally, the most interesting part of the property. It links the pool's services - a chaninging room, a three-piece bath, a sink and buffet counter on one side and a two seating platforms on the other.

Beyond is the pool. (metal gates can close off the pool if necessary to keep small Noah, the Deutsch's young son, and friends from unauthorized wet trumbles.)

The pool is a combination of angles and curves. It starts out to be rectangular, but changes its mind midway to go into a wild curve. The Deutsch lot is wider at the back - 40 instead of 24 feet - and the pool follows along. Also on the bonus land is a pleasant, small fenced-in orchard, with dwarf fruit-tree espaliers on the walls, designed (as were all the planting and many of the other garden pleasures) by Philip Cohen and Debra Dale, landscape architects, who are partners with Simmons.

The master bedroom upstairs has a fireplace and a balcony. The bed is a neo-Art Nouveau marvel of cabinetry by Edward Grunseth. The Deutsches each have a walk-in closet. Stephanie Deutsch's has a built-in vanity, and a door through to the nursery. Noah has his own bath, with animal tiles around the tub appropriate to his age, 19 months. Sarah, Deutsch's daughter by his first marriage, spends weekends in the pretty front room with the eyelet embroidered bed.

A splendid playroom, guest suite, what have you is built in under the eaves. It has its own bath and closets, and a strip of windows with their own awnings. The room was added to the house during the remodeling, so it has its own heating/cooling system, the new Amana through-the-wall heat pump from Code Distributors, of Merryville, Va.

The house was owned by Anne Crutcher, Washington Star editorial and food writer, who also is Stephanie Deutsch's mother. Crutcher had bought it as an investment. Her son-in-law a contractor, Ken Wilkinson, already had started to remodel it. The Deutschs, meanwhile, decided their house was too small for the expected arrival of Noah, their first son. After looking around for sometime, they decided the house could be just what they needed.

"Choosing an architect is an important thing to do," said Stephanie Deutsch. "We could have done a great deal of research, studied the matter carefully, and so on. Instead, we just asked our then next-door neighbor, Tom Simmons. And it worked out well." They counted having their brother-in-law as the contractor as an equally great boon. Ken and his wife, Jennifer Wilkinson, made a stained glass number for the transom over the front door as the final touch.

In all, Deutsch figures the house cost about $300,000, give or take. "It's a lot of money," he admits. "But we got all the custom details we really wanted in a house. And with the prices of houses as they are today, we could have paid the same amount for a smaller, existing house, not handmade for us." CAPTION: Picture 1, David and Stephanie Deutsch's house is almost a catalogue of solar devices; but from the street and from out back, where the Deutsches' son Noah plays there's no visible evidence of the house's link with the sun.; Picture 2, Inside, fans on the ceiling and awnings on the windows help keep the living room comfortable all year. By Harry Naltchayan - The Washington Post; Picture 3, The Deutsches' pool is a combination of angles and curves. By Harry Naltchayan - The Washington Post