A free clinic on energy cost-cutting procedures will be held at 1 p.m. today at the Woodbridge campus of Northern Virginia Community College. Designed for homeowners and small businesses, the clinic includes a 40-minute slide presentation. A question period on specific problems will follow.

M. S. Milliner Construction Inc., of Frederick, Md., has been awarded a $12,000 HUD grant toward the cost of constructing an earth-sheltered, passive solar home. It will be started next month near Frederick. An open house is planned for September.

Rufus S. Lusk & Son Inc., a Washington-based real estate publishing firm, has completed its first compilation of real estate transactions in Frederick County, Md. The 109-page book lists all real estate transaction in the county in 1978 and 1979.

Sixteen houses in Baltimore, eight in the historic Federal Hill area and eight in Fells's Point, will be part of the annual historic Harbor House tour from 1 to 6 p.m. April 13 in the inner harbor area of that city.Information is available from the Society for the Preservation of Federal Hill & Fell's Point Inc. (301) 675-6750.

Michael P. DeChant, a vice president of the John C. Walker Companies, has been appointed to the board of supervisors of the Montgomery County Soil Conservation District, which is responsible for the technical review of storm water management and sediment control plans in the county.

The Fairfax County department of manpower services is working with the Department of Labor and the Northern Virginia Builders Association in training unemployed persons in building and construction skills. Information on the pre-apprenticeship program is available at 691-3221. Information on advanced training programs is at 893-6800.

Walker & Dunlop has arranged $7.5 million in permanent financing for a 12-story building at 1025 Vermont Ave. NW. The owner, a limited partnership headed by Herbert S. Miller, Richard L. Kramer and Gerald L. Dillon, plans to renovate the 16-year-old building.

The National Conference of States on Building Codes and Standards Inc. has signed a long-term lease for a 16,000-square foot building in the SugarOak Office Retreat between Reston and Herndon.

A course on how to sell houses, with or without brokers, will be held from 10 a.m. to 1:30 p.m. April 12 at the Rockville campus of Montgomery College. The cost is $20. For information, call 279-5188.

The Washington office of Julien J. Studley Inc. reports that 331,450 square feet of office space was "pre-leased" in the District in the first two months of this year, about 50 percent more than was committed a year earlier. Leasing in suburban Maryland totaled 389,000 square feet; Northern Virginia, 441,000 square feet.

Eleven courses in real estate are being offered in the spring semester by the Northern Virginia Community College. Information is available at 323-3160.