The D.C. Real Estate Commission now requiires that persons applying for licenses as real estate sales persons or brokers must furnish evidence of satisfactory completion of a course of instruction in real estate principles and practices. Courses approved include those given at American U., Howard U., and Strayer College. The D.C. exam for sales persons will be given Sept. 26 at Harambee House Hotel and the broker exam will be given Sept. 26 at the same location.

Budgets and assessment planning for community associations will be the topic of a workshop to be held today at the National 4-h Center, 7100 Connecticut Ave., Chevy Chase, by the area chapter of the Community Associations Institute. The workshop begins at 8.30 a.m.

A national conference on problem-solving in urban preservation and adaptive use has been schdeduled here Sept.28, 29 by two divisions of the Bureau of National Affairs. The tutition fee is $190. For information, dial (202) 466-8592.

The six-story office building at 2425 Wilson Blvd., Arlington, has been sold by Kilwaiths Associates to the Association of the U.S. Army for $1.8 million. The association will use the building as its headquarters. The transaction was handled by Barmes, Morris & Pardoe Realty Associates Inc.

Panorama Real Estate has opened new offices in Annandale, Gaithersburg and Wheaton. The firm now has 17 offices and more than 350 agents.

A workshop on restoring and furnishing an older house will be held Sept. 23 at Decatur House, 748 Jackson Pl. NW by the Washington chapter of the Victorian Society in America and the National Trust for Historic Preservation. For information, dial (202) 387-4062.

The Washington Suburban Sanitary Commission will hold a public hearing Wednesday evening at the WSSC office in Hyattsville. The topic will be radical changes in water and sewer house connection procedures and fees.

Speakers on varied realty topics are available to civic and other groups by calling the Northern Virginia Board of Realtors (560-7350).

A seminar on office buildings will be held Sept. 28 at the Capital Hilton Hotel by the Apartment and Office Building Association. Topics include computerized accounting systems, GSA leasing policies and security systems. For information dial (202) 293-3995.

The Northern Virginia chapterof the Institute of Real Estate Management will hold a one-seminar on Tuesday at the Tysons Corner Holiday Inn. Robert Demson and Douglas Pierson will be the seminar leaders. Topics will include turnover, rent collection and evictions.