Reston Land Corp. has filed its long-awaited rezoning application for the 85-acre core of Reston's Town Center -- minus most of the specifics that such filings usually contain.

It is clear, however, that the project will be enormous. J. Hunter Richardson Jr., vice president for commercial marketing at Reston Land Corp., termed it "a granddaddy for Reston," combining hotels, restaurants, offices and boutiques in a mixed-use development.

Beyond that, the application is vague and lacks details on the height or density of possible buildings, causing Fairfax planning staff members to view it with some skepticism. Reston officials will have to provide more details, Fairfax planners said this week.

Richardson said details will be submitted as soon as they are finalized. He said exact plans have not been hammered out between Reston Land officials and Reston Land's parent company, the real estate arm of Mobil Oil.

"We are trying to nail down the details," Richardson said. "Mobil and Reston Land must agree."

Richardson said the zoning was filed as is because, "at this point, the driving force is to get into the county's cycle" for action on the proposal.

"We have no real fix as to when the county will schedule" the application for public hearings before the planning commission and the board of supervisors, Richardson explained. He said he would like to be sure action is taken by next spring so that construction can begin before the end of 1986.

Richardson said recent rezoning cases have taken from seven to 10 months. One relatively small proposal filed last November by Reston Land has yet to be acted on because of difficulties related to the final location of ramps leading from the Springfield bypass.

The Fairfax County Planning Commission last week again deferred that rezoning, involving 32 acres, also in the Town Center area, to be known as Baron Cameron Pond.

Richardson said that controversy "will resolve itself."

The Town Center core site is located west of Reston Avenue, south of Bowman Town Drive and east of the planned Springfield bypass.

The 85 acres involved in the latest application currently are zoned residential. "Offices, hotels and residential facilities" are expected to be part of the final plan, according to Peter McCandless, a public relations spokesman for Reston Land.

"It is true mixed-use urban center development. It is everything Bob Simon wanted it to be," McCandless said. Robert E. Simon was the creator of Reston, which has won nationwide praise as a model for development of new communities since it was founded 20 years ago.

"We are looking to start construction by the end of 1986," Richardson said. That schedule depends on favorable action by Fairfax officials on final plans submitted.

The 85-acre core of the Town Center, expected to be the crown jewel of the total Reston development, is part of 460 acres set aside for some type of Town Center development.

Reston has been developed in a "PRC" category, a special zoning category created at the same time Reston was conceived. The category allows mixing open spaces with commercial buildings and a variety of housing styles. PRC designation has, in the past, facilitated rezonings.

The category basically eliminates height and density restrictions, according to Fairfax officials.

However, if the final details of the Town Center core proposal exceed height and densities that are being granted in other mixed-use developments in Fairfax, the plan is certain to generate debate among Fairfax planners, developers and elected officials.

Reston officials said final development plans will be submitted to various Reston citizens groups.

Richardson said the Town Center will not be a regional shopping center such as Fair Oaks Mall in the Fairfax Center area, nor will it be like the three-level retail component of the 107-acre Tysons II mixed-use development slated for the Tysons Corner area.

Reston planners are aiming for "retail with soft goods not now available in the Reston area," such as boutiques and specialty retail centers and "an orientation to restaurants," Reston officials said.

Richardson said the development will be "more urban" than some in the area, but added that "urban does not always mean intensity of development."

Reston officials said the project will emphasize pedestrian mobility, a theme that has dominated Reston's planning since its conception.

Even though the Town Center core is the highlight of the Town Center development, parts of the Town Center already are in place, county officials said.

Construction has begun on the nearby 127-bed Reston Hospital Center and an elderly care facility, McCandless said.

A new county government center also is part of the Town Center area.

The core site is immediately north of General Electric's Data and Information Systems Division operations.