The George Hyman Construction Co. has been selected by the government of France to build a $32 million chancery at 3905 Reservoir Rd. NW, across from Georgetown University's Medical Center.

The 325,000-square foot complex will cover three acres of a 7 1/2-acre wooded site adjacent to Glover Archbold Park. The building's exterior will feature alternating bands of gray and white marble and glass.

The new offices will bring together more than 300 staff members currently working in several locations, and will include space for exhibit areas, a library, and a cafeteria specializing in traditional French food.

There will also be a 247-seat auditorium, six apartments and a garage.

Completion of the project is slated for late 1984. The Hyman company has been involved in several projects in Washington for foreign governments, including the Australian Embassy, the first phase of the Soviet Embassy complex, and the New Zealand and Kuwait chanceries.

Recent developments in commercial real estate in the Washington area:

* Office building leasing in the District in the first six months of 1982 was off 33 percent from last year, to 1,435,930 square feet from 2,138,809 square feet in the same period of 1981, according to Julian J. Studley Inc., a national real estate firm that specializes in office space. The average rental price asked in the District was $27.60 per square foot, a slight decrease from the March-April $28.60 average rental asked. The average rental price for new space in suburban Maryland and Northern Virginia was $16.44 per square foot.

* While demand for industrial space by high technology and industrial firms has continued to rise in Fairfax County, leasing activity has fallen off from the sizable increases recorded in previous years, according to the county's Economic Development Authority.

The county reported that leased high technology and industrial space for the six months from September 1981 to March 1982 was 381,377 square feet. Leasing rates for this space, much of which will be used by telecommunications and defense-related fims, ranged from $6.50 to $10 per square foot, as of March, while space for warehouse and product distribution ranged from $3.35 to $6 per square foot.

Fairfax County needs about 800,000 square feet of new high technology and industrial space per year to meet demand, according to the county agency.

* The Farm Credit Administration will move to a new $13 million building in the McLean area of Fairfax County. The agency will occupy 80,000 square feet in a 150,000-square-foot building to be built on a 12.8-acre site within the Tyson-McLean Office Park at the corner of Dolley Madison Boulevard and Lewisville Road. The agency currently has its offices at L'Enfant Plaza in downtown Washington.

The agency plans to move more than 180 employes into the new building by April 1984.

* Gregg Adams, a Realtor in the Prince George's County and Southern Maryland area since 1967, announced the formation of Adams & Co. Commerical Brokers Inc. The firm specializes in the sale, leasing and management of commercial, industrial and investment properties and has offices across from Andrews Air Force Base in Camp Springs.

* J. Roland Dashiell & Sons has been selected as general contractor for the Fort Washington Health Care Center, according to Fort Washington Community Hospital President Ann Shoch. Shoch said the first phase of the health-care project, a 30,000-square-foot doctors' office building and a 15,000-square-foot emergency- and ambulatory-care center, will open in April 1983.

Thirty-nine national associations established headquarters in Fairfax County last year, according to the county's Economic Development Authority. The county, which now has 215 national headquarters, had only four in 1971.

More than half of the 215 associations have offices in either Reston, Vienna, Tysons Corner or McLean.

Recent additions include the Door and Hardware Institute, leasing 10,000 square feet in an existing building in Tysons Corner's Westgate; the Academy of Model Aeronautics, building a 14,600-square-foot structure on a 1.6-acre site in Reston, and the National Association for Hospital Development, leasing space at 8300 Greensboro Dr. in Tysons Corner.