A consulting firm has urged Falls Church to move George Mason Junior-Senior High School from its present location near the West Falls Church Metro station and build a new school at a cost of $22.5 million to $26 million in a section of the city less likely to be be crowded by development.

The proposal would require approval by city and Fairfax County authorities. The county would have to sell the 18-acre Whittier School site to the city for the new high school. The city also would have to arrange to use the county's five-acre James Lee playing fields adjacent to Whittier.

In a report to the Falls Church School Board last week, the Washington architectural firm of Cannon/Faulkner also outlined short- and long-term solutions for dealing with increasing traffic, development and noise around George Mason, if it decides to keep the school at its present site.

The school is at the intersection of Leesburg Pike (Va. Rte. 7) and Haycock Road, one of the most valuable parcels of land near the Metro station.

Located in Fairfax County, just west of the Falls Church city line, George Mason enrolls more than half of the city's public school students -- about 650 sixth through 12th graders.

Although the school buildings sit on 41 acres, the property is hemmed in by two busy roadways that are scheduled to be widened, and by the Metro station, which is to open in early June.

Mounting concern over the impact that development would have on George Mason caused the city council last summer to approve the $28,000 consultant's study.

Last week, standing before an audience that included School Board members, administrators and council members, Cannon/Faulkner Vice President Howard Melton said the firm's top recommendation would be to relocate the high school to the Whittier site.

While the consultant did not say what would happen to the George Mason site under the proposal, school officials said that all or part of the property could be sold for development, with the proceeds used to help construct the new school.

Melton said the city should acquire the Whittier site from Fairfax County, tear down the existing buildings and construct a new school there.

The Whittier School was closed by Fairfax in June 1984 and the site was declared surplus last week by the Fairfax County School Board. Hillwood Avenue, a residential street, cuts the 18-acre school property in two. There is a 10-acre parcel on the north and an 8-acre parcel on the south.

Melton outlined three ways to build a new school on the Whittier property, but said his strongest recommendation was to build two three-story buildings, one on either side of Hillwood Avenue.

The plan would call for connecting the buildings with a second-floor bridge over Hillwood Avenue. As proposed, the bridge would would be a functional part of the building, containing halls and classrooms.

The building on the larger parcel would be an academic building and the structure on the smaller property would be an athletic building.

Melton said the Whittier site offers a neighborhood that is less congested, making it quieter, safer and generally more accessible to both pedestrians and automobiles.

Another big advantage, he said, is that a new building could be designed with current school needs in mind and would be more energy efficient.

To remedy the immediate situation at George Mason, Melton outlined short-term solutions including construction of a masonry wall along Leesburg Pike to act as an acoustic barrier. He also suggested building a barrier along the Haycock Road side of the school as well as a pedestrian ramp across Haycock Road. Those measures would force students crossing the busy and dangerous street to cross at the light or use the safety ramp.

If city and school officials decide against relocation altogether, Melton said, the best long-term solution would be to essentially turn the school around by reversing its entrances. The new entrances would be at the rear of the school instead of along Leesburg Pike and Haycock Road.

Melton said combined short-term and more permanent measures at George Mason would cost between $12.5 million and $14.7 million.

School board members, city council members and the city manager are scheduled to meet with representatives of Cannon/Faulkner next month to discuss the recommendations.