Oakley Hunter has moved the Federal National Mortgage Association from a building downtown among housing and finance-related institutions and associations to a renovated and expanded colonial-style site on Wisconsin Avenue next to McLean Garden and Glover Park.

The venture cost $37 million, but Hunter, Fannie Mae's chairman and president, said "it would have cost just as much to build a comparable 240,000 square feet in a well-located building." He said 20 sites were examined before the former home of the Equitable Life Insurance Co. was chosen.

George Hyman Construction Co. was general contractor and John Carl Warnecke & Associates the architect for adding a rear wing that matches the original structure and for garden and site work.

Some 560 FNMA employes are working on 11 floors in the two buildings.

Fannie Mae, a congressionally chartered private organization, buys and sells both government-backed and conventional home mortgages.

Hunter and his top staffers have expressed concern over mortgage interest rates. He concedes that housing starts and resales are cooling and adds, "if interest rates continue rising (they now are near 11 percent in many areas), it could be that a new federal mortgage subsidy will be needed by the end of the year."

Hunter was referring to the likelihood of Congress voting funds to provide below-market mortgage loans. That approach was used in the mid-1970 housing slowdown when buyers were unable or unwilling to get new mortgages at high rates.

"Of course, housing is no longer the total whipping boy in a market such as this because there usually is money available," Hunter said. "It's now a question of letting the buyer decide how much to pay for borrowing money on a long-term basis. I think we are even seeing housing outbidding corporations for money."

Hunter also sees a continuing strong market for inner-city rehabilitation and restoration of well-located existing dwellings.

Fannie Mae recently implemented three programs to provide financing mechanisms for those houses. CAPTION: Picture 1, The new Federal National Mortgage Association home is at 3900 Wisconsin Ave. NW which was the headquarters of the Equitable Life Insurance Co. By James A. Parcell-The Washington Post; Picture 2, FNMA chairman Oakley Hunter in one of two formal gardens at HQ