The Ballston Metro Center, a $75 million complex planned to be built atop the Ballston Metro station in Arlington, will feature a 19-story condominium, a 13-story office building and an eight-story hotel, according to plans submitted to the county yesterday.

The complex is the latest project in a billion-dollar construction boom that is dramatically revitalizing the once-sagging business-retail district.

Plans for the project were submitted by International Developers Inc. (IDI), whose president, Giuseppe Cecchi, guided similar plans for the 22-story Rosslyn Metro Center office-retail complex atop the Rosslyn Metro stop.

In addition to the 285-unit condominium and the 210-unit hotel, the project calls for a 10,000-square-foot health spa and an underground garage of 812 parking spaces in an office building that would have 28,000 square feet of retail space on the lower floors.

The Metro Center project is scheduled to be reviewed by the planning commission in December and faces County Board action in January.

Joseph S. Miller, IDI vice president, said that if the County Board approves the project, construction could begin in June, when the Metro transit system expects to open the remaining four subway stops on its Orange Line to Vienna. The IDI Ballston project is expected to take 30 months to build.

Because of the mixed-use nature of the project, which is required in a special zoning district the county created for the area surrounding the Ballston Metro stop, Cecchi said he expected the complex to generate the around-the-clock activity that is missing at such office-dominated Metro stops as Rosslyn.

"It's a tremendous plus for a community to have all the uses nearby so people can circulate and do a lot of different activities in the same environment without having to drive other places," added Cecchi, who also developed the Watergate complex in Washington, one of the area's first mixed-use projects.

The Ballston complex is to be built above the Ballston Metro station -- the current terminus for the subway system's Orange Line and a major bus transfer point -- on a three-acre site bordered by Fairfax Drive and North Ninth, North Stuart and North Stafford streets.

IDI has an agreement with the principal property owner, the Washington Metropolitan Area Transit Authority, to purchase some of the land and lease other sections. Joining IDI in the venture will be Clarence Dodge Jr., board chairman of the Weaver Bros. real estate company and owner of 31,000 square feet of the site.

When the rest of the Orange Line is opened, Ballston no longer will serve as the last stop, thus freeing up for the IDI project space that now is used by buses. The transit agency expects bus traffic at the Ballston stop to be reduced to one-quarter or one-third of its current level, a Metro spokeswoman said yesterday. Bus stops, she said, probably will be relocated to nearby streets.

Gary Kirkbride, chief of the county's planning section, said yesterday he had seen only earlier plans for IDI's Ballston project and was waiting for refined plans in another two weeks by the developers, formally known as the Ballston Center Associates Limited Partnership, to file refined plans, expected in two weeks.

A critical factor behind the project's feasibility is the special commercial-office-apartment zoning district the County Board created at the Ballston Metro stop area, Miller said. That zoning, unique in Arlington, requires that at least half of the building space be residential -- a goal the county has stressed in its efforts to strike a balance of uses around the Metro stop.

Developers frequently have been reluctant to build residential projects because they do not return the profits of an office project.

So in return for the county's residential requirement in the special zoning district, developers have been given extra density rights to build bigger, and thus more profitable projects.