Texas megabuilder/developer Gerald D. Hines collects buildings by the great architects of our time. He has 350 so far -- by Philip Johnson, John Burgee, Charles Moore, Kevin Roche, Robert Stern and I.M. Pei, to name a few.

Now he's collecting in Washington. His first real-estate venture here -- the Columbia Square office building designed by Henry Cobb of I.M. Pei and Partners -- is under construction at 13th and F streets NW, with completion slated for 1986. A second venture -- Franklin Square at 13th and I streets NW, is in the design phase with Philip Johnson/John Burgee.

Washington, says Hines, is "a city we've wanted to get to for a long time. It's a very attractive city. Clean. I like the scale." And, of course, as the nation's capital, he says, "it will be a long-term good market."

It is precisely that mix of the esthetic and the pragmatic -- of art and business -- that has made Gerry Hines what he is today: one of the most-admired developers in the nation.

Hines has built -- and still controls -- a real estate empire said to be worth $4.5 billion, but he doesn't pretend to be a modern Medici.

"Our purposes are different," says the quiet, Oklahoma-born, Depression-bred mechanical engineer. "The Medici hired the best artists of the time to do monuments to themselves -- to their own glory. Today is the day of the corporation, and the glorification of the corporation. You can say it either way: that our buildings are the glorification -- or the identity -- of the corporation. We prefer to use the word 'identity,' " says Hines. "It's a little less . . ."

Hines likes everything (except his buildings) to seem "a little less" than they really are -- including himself. With slicked-down, thinning hair, horn-rim glasses and pin-stripe suit, he looks, at 59, like a trim, boyish, overly modest Robert McNamara. Admittedly "embarrassed but not guilty" about his success, this son of a Canadian immigrant prefers to keep the trappings of wealth under wraps. To wit:

"What kind of a car do you drive, Mr. Hines?"

"A Mercedes."

(His wife Barbara, 35, kicks him noticeably under the table.)

"A Ferrari," he admits, looking shame-faced into his lap like a Sunday schoolboy caught doing something terrible -- like chewing gum in church. "My wife gave it to me -- a birthday present. But it's not a two-door, or a convertible, or anything like that."

"And where do you live, Mr. Hines?"

"In Houston, in a contemporary built some 23 years ago by a local architect. We've talked to Michael Graves about building us a new one."

Any other houses?

"Well, we have a house in Aspen [Colo.] designed by Charles Moore, a neo-19th-century western house with a big tin roof.

"And one in Martha's Vineyard designed by Robert Stern, finished two years ago. We share it with a partner."

Any others?

"Well, there's an apartment in New York, a co-op that belongs to Barbara."

"Shall we tell her how we eat?" offers Barbara. "Vegetarian!"

And where did they find a vegetarian cook?

"In fact, we trained a French chef that we found in the south of France," says Barbara. "He actually worked for us down there."

"We have a house there," confesses Gerry Hines, blushing again. "At Cap Ferrat, between Nice and Monte Carlo, built around 1900. It sits right on the water." It's where he keeps his only boat.

He hadn't mentioned Cap Ferrat before, he says, because "Well, it sounds like we're . . .well, that's not really . . ."

Any other houses in the domestic architecture collection?

He swears there aren't.

Hines always says "we," even when he means "I," as in "We were made an honorary member of the American Institute of Architects," or "The architecture critics have been very kind to us."

In fact, they have been far more than kind. Former New York Times critic Ada Louise Huxtable named his cut-off, trapezoidal, twin-towered Pennzoil Place in Houston, designed by Johnson/Burgee, the Building of the Year in 1975. Now Hines and Huxtable serve together on the board of overseers at the School of Design at Harvard, one of many honors bestowed on the developer by an architectural profession unaccustomed to his kind of patronage -- especially from a speculative real estate developer.

Washington architect Hugh Jacobsen spoke succinctly for his profession. Asked what he thought of Hines, he said simply, "I wish he'd hire me."

For a man who controls 66 million square feet of space -- including half the skyline of Houston -- Hines' Washington perch, rented from Skidmore, Owings & Merrill, isn't much of an office. But it gives him a view over the hole in the ground from which Columbia Square is now rising. He visits infrequently, but likes to establish a presence in cities where his buildings are under way, chiefly to help see that they're fully rented before they open.

The Pei building will be occupied in part by the law firm of Hogan & Hartson. And to encourage others to commit themselves now, Hines made what might be called his Washington debut last spring by sponsoring a show of paintings from London's Dulwich Picture Gallery at the National Gallery of Art. He then hosted the show's opening dinner, where the guest list was unusual for a Washington art party: mostly lawyers and other potential tenants.

"Hines actually came to our firm himself to ask whether we'd like to take space in that building," said one guest, Washington attorney Sam Stern of Wilmer, Cutler and Pickering. "I couldn't believe it."

Hines set out to be an engineer. After World War II, with the help of the GI bill, he finished up at Purdue University, and went to work for a major company in Houston: the Texas Engineering Co., which designed and sold mechanical equipment for buildings. "That's how I learned about buildings -- on-the-job training." He scuttles tales that he was a poor boy who worked his way through college and made good. "Not true," says Hines. "I had the GI bill after World War II. I'm self-made -- with the help of the government."

He tried one investment on the side: a Lincoln-Mercury dealership, which he and a friend took over in 1952. "We lost all the capital we put in it -- $50,000 -- in one year. That was a lot of money in 1952, all earned in the engineering business. I learned I'd better do what I know how to do, which is buildings.

"So in 1954 we began to invest in buildings, and were very successful with the first couple because they were different than the normal office warehouse in Houston. We found that if we differentiated our product a little, people were more interested in doing business with us than with our competitors.

"So I said this is a pretty good formula for attracting people. Why not go a step further? So eventually I went into office buildings, and a little better office buildings, until I got to the point that we engaged Skidmore, Owings & Merrill and won the competition for the One Shell Plaza building in 1966 -- the first 50-story building we had ever done. It cost about $38 million -- a big building in those days, and the largest building that had been financed by Houston banks, ever. Today that building would cost $170 million," says Hines.

And that's how he got so rich: he still owns or controls (through a variety of agreements) most of the buildings he's built, including the handsome RepublicBank Center in Houston (Johnson/Burgee, 1983); Southeast Financial Center in Miami (Skidmore, Owings & Merrill) 1984; the Transco Tower in Houston (Johnson/Burgee) 1983; United Bank Center of Denver (Johnson/Burgee) 1983; and Texas Commerce Tower in Houston (I.M. Pei and Partners) in 1982.

The firm had 10 people in 1966. It now has 1,200 employes.

Apart from the model of the Pei structure in his Washington office, Hines seems proudest of his wife Barbara, a German-born designer and former foreign language teacher who grew up in Australia, daughter of an engineer, and still has a soft Australian accent.

She, in turn, seems proudest of their new baby, Serena -- her first child (Hines has two grown children by a previous marriage). Though she can seem at times better versed than Hines himself on details of the Gerald D. Hines Interests, she says her only real involvement with the business was her redecoration of his office in Houston -- "hardest job I ever had."

Hines and his wife Barbara met at a dinner party in Germany five years ago and were married a year later. They cross-country ski together. His climbing and running of former days were sidelined by a knee injury two years ago, he says. "Now I mostly fast walk." She gives her husband good marks for spending time at home, but says "When I need something fixed in the house, I wait . . . It took us longer to build our new bathroom than it took to build Transco Tower!" -- 1 1/2 years.

Hines says his interest in using famous architects developed for pragmatic reasons, not out of any profound interest in art. "We have a very selfish motive. We expect to make money." In fact, his association with critically acclaimed architecture began rather accidentally on a ski slope, when he met Bruce Graham, lead partner in the Chicago office of Skidmore, Owings & Merrill. "We wanted to win the Shell competition, so I thought it would be important to have a nationally known architect," says Hines. "We feel today that that building stands as a sculptural piece. It worked out very well for us, and gave us the reputation . . ."

Then he ran into another client, the Rocksteins, major manufacturers of furniture and millwork products in Houston, who introduced him to Philip Johnson, with whom Hines ultimately built the Pennzoil building.

"There was a building that set a trend, that broke away from what you might call the Miesian box," says Hines. "That was a milestone, I think, in American architecture. The head of Pennzoil wanted to do something different. As he said, 'It was an unknown company in an unknown business.' Pennzoil became known for that building."

Since then, Hines has done 10 more buildings with Johnson/Burgee, including Manhattan's first oval office building -- 53rd at Third, opening soon. Hines is especially proud that Philip Johnson will be moving his offices there after 30 years in the Seagram building, which he helped Mies Van der Rohe design.

Johnson says the move is due as much to economics as design. But he has nothing but praise for Hines.

"Gerry," says Johnson, "is the most glorious backer we have ever had. He started a revolution in the developer world. The concept of paying a little more for quality and keeping their buildings as a point of pride is now common.

"We educated each other . . . I'd never worked for a developer before he came to us . . . they used to be considered riffraff, speculators, who built as cheaply as possible and then got out. He took the chance that our strange, unfamiliar design would be a selling point -- a 'point of difference,' as he calls it -- something different from that glass box down the street. And we were able 20 years ago to give him a point of difference that gave him a better building and more rent."

Other Hines projects currently under way include Manhattan's Hutton building at 40 W. 53rd St., a joint venture of Hines and CBS and designed by Kevin Roche John Dinkeloo Associates ; Boston's 500 Boylston St., designed by Johnson/Burgee; and Framingham, Mass., Point West Place by Robert Stern.

"We've also worked with Hellmuth, Obata & Kassabaum who did two major projects for us: the Galleria in Houston, and the Galleria in Dallas, both of which are multiuse, with office buildings, major retail, ice skating rinks, clubs and hotels, all in an interrelated complex," Hines says.

He is also working with Roche/Dinkeloo on Ravinia, a 42-acre complex in Atlanta with 1.7 million square feet of office space and a 500-room hotel.

His rationale is simple and clear: "The choosing of good architects has become good business," says Hines, "because it creates identity. And not only does the identity create a place in that city that is recognized; other tenants will come into that building because it has good identity, and they like good association.

"And that's the reason it pays for us. And it has paid in the past -- as long as you don't pay too much for it. And we have methods of controlling that to keep it down to a reasonable level of cost addition." In fact, says Hines, most of the time it's not an increase in cost. When it gets too expensive, that's when Hine's own creativity -- and engineering experience -- come into play.

"We found a way to use these very expensive architects in a way that is financially viable and profitable," says Hines. His approach differs from that of the Mellons, who also used I.M. Pei when they built the National Gallery East Wing. That, Hines points out, is an extraordinary building but not a commercial one. "The Mellons' approach was just give me the best you've got. We said that too, but for us it has to make sense -- and dollars too. Compromises have to be made all the time. But it's a creative partnership: We make decisions together."

Is he the ideal client? "I don't know about that. But we do have a lot of fun. We do understand the architect, and he can sketch something out on the facsimile machine, send it down to us, and we can say if it will go or not go, and move on to the next step. Also, because we've had so much experience, we don't let him get into a trap where he gets way out and overruns the cost.

"We say it's very easy to build a cheap building, and very easy to build an expensive building. It's very hard to build an outstanding building at a reasonable cost, and that's what we try to do. It's a working relationship."

Hines explains his special niche in the world of speculative developers -- dirty words in some quarters. "A lot of developers are financially educated people, profit educated," as opposed to being engineers. Does he mean they're more interested in profit than product? "Well, let's just say their original background is financial in character.

"There's no reason money can't be made in a way that enhances the city," says Hines. "We feel that development should enhance the built environment. That's what we work for. And the excitement. A building is an appreciating asset, and if it does have identity and it is good architecture, it will increase in value.

"Some of the most exciting things are happening in architecture -- a whole new art form that's expressing itself in a nonconventional palette. That's what's exciting about it: These architects have broken the mold," says Hines. When it comes to developers, so has he.