GLOUCESTER -- "Why don't people always hire an architect when they want to build a house?"

Jeremiah Eck, architect, is in the living room of the weekend getaway he designed here for Maggie and Joe Rosa of Winchester. He can't figure it out. "If you need brain surgery, you go to a brain surgeon," Eck continues, sounding baffled. "You need an architect to customize your house, to fit it to the site and the owners. That makes a lot more sense than buying some standard developer's neo-Colonial that may stick out like a sore thumb. It may take a little more time, but it isn't any more expensive."

The house where Eck is standing is his strongest argument. From a distance, it rises out of the granite boulders of the Massachusetts coast as naturally as a pile of weathered driftwood planks. Up close, another image takes over. The extended sheltering roof, looking out to sea, suggests a person with a hand held up to shield the eyes from sun or rain.

The architecture speaks of rough weather, of shipwrecks, of far horizons. This is a house that wouldn't be quite right for any other site, which is why it is perfect for this one.

Inside, it's even better than out. Eck has planned the experience of entry like a choreographer. You come through the door into a low vestibule. You can see steps ahead of you, leading down toward something bright, but you can't yet see what it is. There are only six steps and they're shallow, not steep, so it feels as if you're descending a gentle landscape slope. As you do so, the space of the living room explodes upward and outward. By the time you've taken that in, you've advanced further, to a point where you're stunned by an ocean panorama that stretches to infinity beyond a row of great windows. In the middle distance, placed as precisely as if by a painter, are the twin lighthouses of Thacher Island.

"I wanted you to have the feeling that you're sitting out on a rock, but sheltered from the weather," says Eck. "The house should nestle and protect you. It should express the fact that this is a place where there are storms."

Joe and Maggie Rosa work in the biotech industry. He's working on a multiple sclerosis treatment, she's experimenting with ways to transplant organs from pigs into people. Maybe it's the background in biology that made them want their house to grow organically from the site. They picked Eck as their architect after seeing one of his houses on the cover of Fine Homebuilding magazine, which, says Eck, is his favorite publication.

"Architecturally," says Maggie, "all I wanted was that the land dictate the style."

It sounds like an obvious request. But then you look up and down the coast at other new houses nearby. Often they're paper-thin, Disneyish clones of architectural styles of the distant past. Often they feature green lawns and brick walks and brass lanterns and arched windows and a lot of other doll- house motifs that do not belong on these rugged granite cliffs. Houses on this coast should fade respectfully into a landscape that will always be far greater than themselves. Too frequently, instead, they dance on the rocks like performing clowns.

Indoors, Maggie's requests were equally simple: the usual spaces, plus a couple of guest rooms, and a kitchen that is open to the living and dining areas -- "so people can flow in and out." The kitchen, in fact, is the only part of the house that looks expensive. Its curving pale gray cabinets, above a sweeping dark granite countertop, do suggest the flow of people. They also suggest fog over rocks.

Maggie's favorite room is a kind of add-on. It's the space farthest out on the rocks, a small room a couple of steps down from the living room with a glass prow like a pilot's cabin. "The rocks here come up and seem to wrap you," says Maggie. "You feel a little bit safer."

She goes out of her way to credit the general contractor, David Pynell, for the excellent craftsmanship. Family helped too: Joe's brother crafted the elegant stainless steel brackets that support the indoor stair balusters. Total cost of the house, including the coastal land, was about $700,000.

Infinite care is taken to join the house to the site. The fireplace, for instance. Its hearth appears to be -- although it really isn't -- an outcrop of the actual granite ledge the house is built on. A pile of oversized boulders, piled up at one side of the fireplace, extends the metaphor. These are motifs that were dear to the heart of the great architect Frank Lloyd Wright, who, like Eck, loved to build with materials taken from a house's actual site, so it would seem to grow naturally out of its surroundings. There are other reminiscences of Wright, too, among them the insistent horizontality, the overhanging roofs, and the living-room ceiling made of folded planes picked out with simple wood strips.

The floor keeps stepping up and down. You never lose your sense, as you move through the house, of the uneven rock ledge underneath. Nobody has blasted it flat to make a convenient building site. Eck is proud of the fact that virtually no change was made in the natural landscape.

Most of the materials have a pale, summery, salt-washed look. Birch floors. White walls with warmer-toned trim. Blue-gray tiles or carpeting in places like the kitchen and bedrooms. Rough unfinished stucco around the fireplace. Outdoors, a big chimney, also of stucco, that slants back a little as if the sea wind had been pushing at it, or as if it were the superstructure of a ship. Gray stained decking and shingled walls, with the shingles lapped tighter than normal with a narrower "exposure" of each one. "It gives a look of being pulled close against the weather," says Eck. "It's the kind of detail you never notice."

There's a lot of glass toward the south, where the ocean is, and a more solid wall toward the north, where the nearest neighbor lives. The glass tends to angle back and forth in a faceted way, like the surface of a diamond, subtly aiming you toward the best views.

As he finishes giving a visitor a tour, Jeremiah Eck is still issuing complaints -- jeremiads, you might say -- about how people need architects. ''The whole point is to find something in the landscape you can hang on to," he says. "Something that will make the house unique. But so often, commercial builders begin by negating the site. They plough it flat, they destroy the trees. Then they put up houses that are lies. They pretend to be Colonial mansions, or something else they're not."

He thinks for a moment. "Your house should not be another lie in your life," he says. "It should be a place that heals you from the lies and hype of everyday experience."