WHEN GEORGETOWN architect Hugh Newell Jacobsen presented his design for their house of his Pennsylvania clients, the wife stood up and said: "I'm never going to live in a house like that." And she left the room.

Two weeks later, after studying the plan, the clients called back and said they'd decided to build it -- and throw out most of their funiture in favor of whatever Jacobsen would choose.

When Chicago architect (and part-time comedian) Stanley Tigerman saw the same house, he said: "Brillant!"

Jacobsen felt a warm glow and prepared his thank-you speech. And then Tigerman, who has a reputation both as an artitecture philosopher and entertainer, added: "Now that you've shown you can do it, don't ever again. Otherwise you'll never get another client and have to support yourself by lecturing the way the rest of us do." The houe arouses strong emotions. Some long-time admirers of Jacobsen say they'd just as soon not talk about The House. Yet it has already appeared in full lavish color in three magazines and won awards from both the 1981 American Institute of Architects/Housing Magazine's Homes for Better Living and from Architectural Record Houses/1981.

No one should make up his mind about the house from the photographs.It is tempting to consider the house a collection of spectacular photographs by Robert Lautman. (Readers of slick shelter magazines, which seem to have a Jacobsen house in every issue, may suspect, as I've said before, that Jacobsen doesn't exist, he's only trick photography by Lautman.)

The owners would not let their names be used because already they have had as many as 100 people in one day come to see the house. They explained that they chose Jacobsen originally from seeing his work in magazines. "We had researched various architects," the wife said, "and we chose Hugh because we liked his elegant simplicity."

One owner agrees the house is not fairly judged by reading about it or looking at pictures: "I think Hugh Newell Jacobsen's work needs to be experienced with all one's senses. His architecture exposes you to the surrounding countryside in large blocks, so though you're inside, you never feel closed in. So many of his clients speak of their happy houses. You feel happy inside because you're not confined, the houses are open and expansive.

"The repetitive, correct proportions of each segment of our hosue makes a harmony. When I come back to the house after walking the dog in the morning, the house seems alive, the rims of glass ripple with light like the rings when you throw a stone into a pool."

Yet to the Modernist mentality, the house is not honest. Form does not follow function, not even at arm's length. You might even say form turns on its heel and goes the other way. There are even more chimneys than there are fireplaces.

The facade of the house is just that -- the classic instance of the Queen Anne front and the Mary Jane back. It doesn't even have the excuse of being a historic facade deemed worth saving. Nor does it "match" the other houses on the street. The other houses are indeed historical styles, but a mix of pseudos. In the Post-Modern vernacular, the Jacobsen house is witty.

The owner originally objected to the 18th-century face on the house. "But after I studied the model, it reminded me of a cloister nearby that I had always admired. And I began to understand that the 18th-century facade of the house had the same basic simplicity that the 20th-century rear has. I also decided that an assertive modern house would not be welcome in the neighborhood.

"I was also very unhappy at first with the thought of the small panes of glass on the front of the house. But they don't bother me at all now. When you're inside the house, you're not aware of the divisions. I'm not sure how Hugh made that work.

"My husband was fascinated by the bands of glass from the beginning. I think it's fair to say it was the most challenging of Hugh's house to build. You realize that the segments are connnected only by glass. The complex design took an intrastructure of steel to make it strong enough to withstand the winds. Yet you are not aware of the steel," she said.

The facade is a series of telescoping clapboard units, getting smaller as they go -- though the client knocked off the plan for a dog-sized section at the end. "Tigerman said I should have build it. He loved the idea of a man going in the big door and a dog coming out the little door," Jacobsen said.

Jacobsen is a strong runner-up for the title the most articulate architect in the country, after Philip Johnson. And Jacobsen has much to say in defense of his historicism:

"The site is in the historic Pennsylvania countryside. It's full of mid-18th-and 19th-century houses built by the followers of Amish, Puritan and other religious societies. The clients' lot is at the end of a half-mile cul-de-sac, a subdivision mostly of the homes of executives of Armstrong Cork. The houses were fine old 1900-1914 Coca-Cola colonials and Bankers' Tudor.

"The terror of those families when they heard a Moderne Architect was going to distrub their serene landscape!" Jacobsen said. "But I didn't want to destroy what they had."

Jacobsen has designed in the modern manner many new houses, as well as many remodelings and additons to traditional houses. He is the architect for the new house just built by Jacqueline Kennedy Onassis. Jacobsen has also an imposing body of work of nonresidential architecture, including his current remodeling of the American Embassy chancery in Paris.

At least twice before Jacobsen has taken an existing house and doubled it with a glass link between the old house and its new Siamese twin. But this is the first time he has built a house with a historical facade from scratch.

"I was on an airplane one day, and I thought again about those telescoping houses you see so often in Pennsylvania. When the early families would have another child, they would bump another house against the one they had, a bit lower, so they could keep the flashing. I had never seen more than three pavilions. But the one I designed has seven."

Jacobsen has used the telescoping plan on a house in this area. And recently George Hartman/Warren Cox used a similar scheme on a rear addition to a Chevy Chase house. Neither goes to the extreme of the Pennsylvania house.

The house not only becomes lower as it goes along but it also takes a step back with each section. A mirror glass strip fills in, beginning at the brick foundation level and going up over the roof. This device floods the house with waves of light. The funniest devices are the upper windows, which also get smaller and smaller as they disappear under the roof.

Hardly anything is as it seems. From the outside it looks like it has four chimneys. But on the inside are only two fireplaces, the other chimneys are vents. The lowest windows in the first section, the living room, seem to be of the basement. They aren't, they're in the first-floor room.

The windows which seem to be of the second floor in the second section are not -- they're in the upper volume of the three-story-high front hall that goes up to the ridge.

The windows are broken by mullions and muntins into 15 squares, so many cross pieces you wonder how the light managers to squeeze in, but the house, like all Jacobsen's houses, has wonderful light.

The real shocker, and to me by far the most beautiful part of the house, comes at the southwest gable end of the house. Mirror (one-way) glass covers the entire 2 1/2-story end, 38 feet high. Most of the panes are in 4-by-10 foot panes, set in a heavy steel-stiffened wood frame. In the day, it seems like an enormous mirror paying homage to the countryside. This is, as far as Jacobsen knows, the only use of such a mass of reflective glass for a house, though many office buildings have used the material.

When the sun shines on the glass, you can't see in. At night, you can. It looks, admits Jacobsen, like a doll house, a classic doll house lwith the third floor going up to a steep peak. To give privacy, Jacobsen has had planted a grove of 34 dogwood trees. Unfortunately, since dogwood trees don't grow very high, the upper floor will still provide a free show for the neighbors. Except -- ah, Jacobsen the "functional modern architect" (as Philip Johnson says of himself when he's done something especially outrageous) -- has designed shutters for most of the windows.

One of the owners said she never feels exposed in the house. "We're on a quiet street and the glass is so oriented that you'd have to deliberately position yourself to look in. I so enjoy the light and the views of the outside, that I don't want to close myself off from it."

The glass gable wall faces southwest. Jacobsen says the heat never turns on during the coldest days. "It's insulated glass of course." The owner reports that even in the summertime, when you'd expect a heavy cooling load, the bills are not as bad because of the reflective glass. "People are always so poud of their free solar heat in the winter, but they never think of the cost of getting rid of the summer heat from south glass," Jacobsen said.

He said an overhang, the classic answer to south glass, wouldn't work here. "It would take one 44 feet wide to shield that high a building," he said.

The back of the house is less surprising. Good old large units of sliding glass for most rooms lead to an expansive patio. Bluestone floors cover the entire first floor (except for quarry tile in the kitchen) and extend onto the patio, unifying inside and out. "It's so easy to maintain," said the owner. "I just use the built-in vacuuming system."

Jacobsen, who prefers to do the interior design of his houses as well as the exterior, has chosen simple, classically modern furniture, mostly made of large chunks of leather and burgundy velvet, for the living room and the study, with a glass table and Marcel Breuer Cesca chairs, upholstered in leather for the dining room. The clients' own collection of carpets is used with great effect.

"We had so many furnishings. We sold it all when we moved into this house," the owner said. "We also had many artifacts we had brought from travels in other countries. We packed most of those things away and I bring out a piece or two at a time. I don't have much put out. The house tells me not to. This house doesn't stand clutter."

Jacobsen said, "I don't build houses unless they work. No matter how advanced the architecture, you have to be able to walk in the front door, hang up your coat, go to the bathroom find the stairway, see the living room, make a drink and discover the plan."

Jacobsen, a master at floorplans, has fulfilled all these points in this house. When you come in the front door, you can walk three steps down to the living room to the left, or go straight ahead to the circular staircase, set into the fireplace wall. Opposite the stair are the bathroom and a bar backing up to it. "If someone's telling a funny sotry, you don't want to walk to the kitchen to mix a drink just at the kicker," Jacobsen said. The bar, in the hall, is convenient both to the living room, the dining room, the library and the patio.

To the right of the front door are the library to the front of the house and the dining room to the rear. The kitchen and its breakfast room are beyond both. A second powder room, utility room and storage room (with two barn doors to make it easy to bring in garden furniture) are the three final pavilions. Upstairs is a large master bedroom with a seating area, and a second bedroom and bath. At the tallest end is another bedroom and bath on the third floor. There is provision for another bedroom and bath over the kitchen. A full basement with a family room and fireplace extends under the house. Because, I presume, it would not fit at the little end of the telescope, the garage is set behind the house, across a family entry court.

Jacobsen estimtes that the house's 4,000 square feet would cost $650,000 to build today.

The house, whatever you think about its false front, is spectacular.

The owners say it's like living in a work of art. And the rest of us can agree it's the most entertainment we've had in residential architecture in some time.