Robert Thoburn, a former member of the Virginia legislature, has filed a special exception request with Fairfax County that would allow him to build a private school for 576 students on more than 37 acres of residentially zoned land in the Vienna-Oakton area.

Thoburn would like to construct a four-building, campus-like school complex complete with athletic facilities on land that was once part of what is known as the Hannah Farm, at Vale Road near Hunter Mill Road.

In addition to the application to operate the private school, Thoburn has filed an application seeking cluster development for single-family houses on 21.5 adjacent acres.

According to plans filed with Fairfax, 18 homes would be built on a cul de sac and pipestem lots. The road would run alongside the school property and would be paid for by Thoburn.

"We hope to be in operation by the fall of 1986," Thoburn said, referring to the Vale Road site. Plans call for one-story classroom buildings and a two-story gymnasium on land surrounded by woods behind the old farm.

Thoburn would move his Fairfax Christian School from rented church facilities that the school has occupied in Fairfax County since Thoburn sold the school's former 34-acre campus on Popes Head Road near George Mason University in 1983 for an undisclosed price to the Islamic Saudi Academy. That sale was financed by the Saudi government. Last year, Thoburn purchased approximately 60 acres that were a part of Hannah Farm.

"Many people know this as 'Hannah' Hill," Thoburn said this week. A lot of children in the area sled there and will be glad to know that the hill still will be here, Thoburn said.

One of the original owners of the farm continues to live in the farmhouse that sits on land fronting Vale Road that was not sold to Thoburn.

Thoburn said the cluster proposal leaves several acres in open space and better protects stream valleys in the area than would development without clustering. The subdivison will be known as Hannah Hills.

Prices for the single-family homes would range from $350,000 to $450,000.

"I have had a number of custom builders who have approached me since I filed the application. It is a situation where we can create the whole living environment," Thoburn said.

The proposed school site and the cluster-home site are zoned R-1, which permits one house per acre.

The Fairfax County Planning Commission has scheduled public hearings on both proposals for 8:15 p.m. May 15.

The application for the school calls for several athletic fields, including two partly in what the county calls "environmentally sensitive" stream valley areas.

The county planning staff this week had not completed its recommendations to the planning commission on either application.

The cluster/residential proposal includes more pipestem lots than generally are permitted in subdivisions. But similar proposals in recent months have ended with compromises between developers and county officials.

Approximately two acres facing Vale Road adjacent to the site also are owned by Thoburn but are not part of the current efforts to change the use of the total site, which includes about 60 acres. The rear tract where the school and houses are proposed also includes an existing house and four acres that are to be included in buffer zones.

The Hunter Mill Defense League, a newly formed citizens association actively involved in land-use changes in the Hunter Mill area in recent months, has not taken a stand on this proposal, according to a spokesman for the organization.