Audrey Moore, the Fairfax County supervisor known for giving development in the county the critical squint, described a massive new project approved Monday in what was, for her, a rare word.

"Beautiful," she said.

Centennial Gateway -- the 80-acre, $325 million development just west of Fair Oaks Mall that officials hope will become the heart of the Fairfax Center area -- has come a long way from the Tysons Corner-like cluster of office buildings its developers originally proposed 15 months ago, say county officials and developers.

County supervisors say they hope the approval process for Centennial Gateway and the tough stand officials took on changes they wanted will be a prototype for other developers who want to get their projects approved. In this case, developers came up with the amenities the county wanted: 600 town houses, a promise of a $5 million contribution for a highway interchange, three lakes, parks and a Civil War monument, among other items.

"This could be a real breakthrough for the county . . . a real signal to everybody," said James M. Scott, the Providence district supervisor credited with guiding the Centennial Gateway evolution. "I hope this becomes a model for how to deal with developers."

When the project, expected to be built in stages over 11 years, is finished, it will include 10 office buildings of up to 10 stories each; three manmade lakes surrounded by trails; a 14-story, 350-room hotel and conference center; 20 acres of open green space and trees; 600 to 800 apartment or town house units; several small commercial areas, and, as its visual centerpiece, a two-acre monument to the Civil War battle of Ox Hill, which took place on the site.

A quarter of its land will be devoted to lakes, open green space and trees -- nothing at all like Tysons Corner, which has no parks or public green space.

When Scott saw the first set of plans for Centennial Gateway, he said he decided that the standard-issue collection of office buildings on about 30 acres was not what the county needed. "This is the place where we have really got to take a hard stand," Scott said.

The development company, he said, was dubious when he urged them to rethink their plans. "Their reaction was, 'Well, gee whiz, we don't think residential will work out there.' But, to their credit, they went back to think about it . . . . It took a developer who was willing to listen."

The company listened to the suggested revisions and modifications of community members and county staff at a round-robin of 47 meetings over 15 months.

"When the county made it clear that the office park we were offering did not truly meet their goals, we literally threw out $500,000 worth of planning work and started all over again," said Robert Fink, special projects coordinator for the Centennial Gateway developers, which has built other office parks in the county, including Sunrise Technology Park in Reston.

"Every time we sat with a new community group or a new staff person, there were changes," said Fink. "Switching buildings, changing shapes, improving pedestrian aspects, the changes were by the week."

Not only did the Fairfax development company discard its original planning, it discarded its original planning firm and hired the prestigious architectural planners Welton Beckett and Associates, of New York and Los Angeles.

Centennial Gateway will be on a piece of heavily wooded land in the rapidly developing triangle known as Fairfax Center, bounded by Rte. 50 on the north and I-66 to the south. The Springfield Bypass, the so-called Outer Beltway, will eventually cut through just to the west of the triangle. And, if county supervisors have their way, the headquarters of the county government will be located just to the southwest.

By the year 2000, officials say, they hope Fairfax Center will be downtown Fairfax County, a lively neighborhood of offices, homes, shops, open green space -- hospitable and accessible, without traffic tangles.

Even Moore, sharply critical of John T. (Til) Hazel's almost purely commercial Fair Lakes development to the west of Centennial Gateway, said she's optimistic that the board will continue its tough stand with future development projects.

"I hope it sets a little better pattern than the pattern they set at Fair Lakes," she said.

"If this is in fact a kind of precedent, if it is a foretaste of what actually occurs out there, it will be a very lively, unusual, if not unique, suburban center," Scott said. "I think it's a very exciting beginning."