The outside of real estate developer Samuel Pardoe's semi-detached Georgetown house is very correct: rosy bricks, old brick wall, five-color cobblestone entry court, small paned glass. Nothing offends the eye of the Fine Arts Commission. No blemish mars its perfection or disturbs the neighborhood.

But behind this blameless facade is an electronic fun house. You've heard of home media rooms or entertainment centers? Pardoe's whole house is, as they used to say in the 1960s, a happening. Three hundred people came to his housewarming. "It's not a family type of house," said Pardoe. "Some people just laugh at it. I think it's a bachelor's pad."

The house is actually two connecting units, each of which cost about $485,000 to build, says Pardoe. He rents out the companion house.

Pardoe is a trim, neat, quiet bachelor in his well-cared-for mid-40s. He has a soft southern accent, perfect manners-- and a fiendish imagination. He's a top roller who made his name as a developer by building the most expensive speculative houses in town.

Architecturally, his houses might be called Post-Gadget, influenced strongly by Early Scavenger. He has a full-time antiques hunter, Nancy Lussi, who scours the countryside looking for pine mantels, stained glass, paneling and such embellishments. His 70-odd previous houses have held such marvels as secret rooms, hidden wine cellars, indoor fountains and electronic magic. "It isn't the furnace that sells the house," he said. "It's the Batman wallpaper."

His own house and its Siamese twin almost didn't get built. The building permit was a cause c,el,ebre. The neighbors complained because the ground once belonged to its neighbor, the famous Dodge House, built by the architecture and landscape firm of Downing and Vaux. The neighbors protested that building on the land would ruin the ambiance of the Italian-villa-style Dodge House. After a year and a half of lawsuits, the building permit was granted.

During the wait, Pardoe was thinking of more and more things to put in it, with architect Michael Patterson figuring out how to do it.

In the dim, narrow front hall with

its rich Persian rug, nothing sur prises the eye. The hall is planned

to lull visitors so that their aston ishment will be greater when they come into the living room.

The space suddenly explodes, up, down, sideways. The ceiling is 32 feet away. And what a ceiling: at night, dozens of colored lights plus a pulsating strobe dance on and off in time to the music. Two large electric fans keep the air in motion.

Lurking in the northwest corner is Pardoe's escape route: a brass fireman's pole, higher than most, going up, up to the master bedroom.

"After I've overslept in the morning, I grab onto the pole and slide down and dash to the car in seconds," Pardoe said. "I learned how to come down it from the man who installed it. His son was a fireman. You don't just slide your hands down--you'd burn them. You grab and then release, grab and release."

So far, Pardoe has had only one major casualty. "Some friends of my nephew's came up from the University of Virginia for a party at my house. They love partying here, because I don't tell their parents what they do. Anyway, they brought a lot of beer. And one boy came down too fast. He hit his head. We had to rush him off to the hospital for 12 stitches. When he came back, he slid down it again. But he was soberer."

For less athletic types, Pardoe has another thrill: an elevator similar to those made famous by John Portman in the Hyatt Regency. The elevator and its shaft are made of smoked glass. The cage is framed by lights, in the manner of the lights that encircle a theater makeup mirror.

Going up in this conveyance is a thrill: Floors and landscape speed by, as you, without visible means of support, rise above it all.

"The elevator is fun, but very practical. I would never build a multifloored townhouse without one," Pardoe said, firmly.

Two balconies, one stacked behind the other, are terraced on the north side of the living room. They remind you of the hanging gardens of Babylon.

The fireplace on the west wall with its high chimney looks like an exclamation point. The east wall is all brick.

In the living room, a switch causes a prissy stained glass door to close off the bar, in case the preacher comes. The bar itself is heavily carved and paneled wood. Set into one wall is a frightening electronic panel that controls the lights --and who's to say what else? The closed-circuit television monitors the front door and other critical spots-- Pardoe was burglarized once and doesn't intend to be again.

The decoration of the room is not at all outr,e. The soft, almost Art Deco furniture, covered in a blue and coral print, was custom-made in New York by De Angelos. The coffee table with its heavily carved top was Pardoe's mother's hope chest. "She carved it herself," he said.

Large windows, arched at the top, on the south side flood the room and the white painted balconies above with natural light, even on a dim day. The glass invites the visitor out to the patio.

The pool is only 10 feet by 16 feet, but big enough to get wet in. Its black surface makes it an ornamental reflecting pond. In the middle is a fountain, which retracts for swimming.

The terrace's brick comes right up to the edge. Trees and seasonal flowers are set into the beds around the brick wall's perimeter. The trees had a hard winter but seem to be coming back.

Giving the grand tour, Pardoe takes it from the top. Every body goes up in the elevator and walks back down, inspecting levels. The elevator trip is not without its frights: just when you think it's run out of up, it goes on another story that you can't see from below.

The top floor is Pardoe's private hideaway, a sybaritic salon. A breakfast kitchen is just outside the bedroom. The king-size bed is on rollers, so it can swing to face the glass walls' panoramic city view across the roof deck. The fixed headboard carries a burden of family photographs. Also built in are controls for the curtains as well as the entertainment tower across from the bed, which holds the stereo, the Betamax and the television. Another set of controls manages the lights and air-conditioning.

A small hall is hung with old newspaper clippings and photographs of Pardoe's real estate and building ventures plus those of his grandfather. The elder Pardoe came to Washington as a carpenter at age 18 and ended up building a number of landmark structures, including the 1910 Hotel Continental, now torn down.

The adjacent bath has some of the brass fixtures from the old hotel. Mexican tiles surround the wash basin. On one side is a well-equipped exercise room, with a television to make it less odious and, of course, the omnipresent television monitor.

The tub is a Jacuzzi whirlbath, warmed by a skylight, the size and shape of the tub. Lights rim the skylight so the bather can bask at night as well. The shower is a steam room. The toilet hides discreetly in its own cell.

At least the plumbing in the bathroom isn't electronic--as it is in the powder room off the front hall. When your hands approach the faucets of the powder-room wash basin, the water turns on (carefully adjusted to the proper temperature). Take your hands away, and the water turns off.

The living room atrium pierces the third floor. On the south side is a guest bedroom with a pair of handsome pine four-posters from the family estate in New Hampshire.

Across a bridge is the library, which is full of Pardoe's tricks. He opens a panel, takes out a switch (he's adept at palming it to add mystery to what's about to happen), and suddenly a toy train begins to race around the cornice, tooting as it goes.

Another flick of a switch and a viewing screen rolls down in the center of the bookcases. A built-in closet holds a slide projector avnd the slides.

The door to the bar came out of an English pub. A full bath, behind the other door, allows the library to double as a guest room.

The library has a wall open to the living room below, but shutters fold to give it privacy when needed. The furniture is London club style--soft leather sofas and dark wood paneling.

The second floor, one more down, holds the dining room and breakfast room-kitchen. The dining room has a large English dining table. On this, he uses china hand-painted in the '20s by his mother, Helen Prescott Pardoe. One large bowl is high Arts and Crafts style, with painted waterlilies and frogs. "Selling her hand-painted china helped the family weather the Depression," Pardoe says.

In the basement is another guest room and bath, plus utilities, and, of course, the wine cellar, entered only through a spiral staircase from the living room bar.

What will Pardoe think of next? Well, try townhouses with towers, balconies, studios, moats, guest houses and inner courts, on the Virginia Potomac Palisades. Asking price: $1.1 million, the most expensive speculative houses ever built in the area. If he's wrong--and he hasn't been so far--he says, "There's always the jump from my roof deck, 40 feet up."