A complex of 18 town houses called Tree Tops is being built in the Seabreeze area of Dewey Beach-Rehoboth Beach, Del. by North Shores Inc., headed by Daniel G. Anderson. The contermporary dwellings were designed by architect Frank J. Duane Jr. Prices begin at $64,500. Spring occupancy is planned.

Morning, evening and weekend courses in real estate are planned for the fall semester by the Northern Virginia Community College in Annandale. Registration begins Monday. Courses are designed for both professionals and lay persons. For information, call 323-3160. A special course on real estate appraising will begin Thursday. For information, call 323-3168.

More than 102,000 square feet of office space has been leased to the Chesapeake & Potomac Telephone Co. of Maryland in the new Marriott Corp. headquarters building being built in North Bethesda. The Carey Winston Co. arranged the long-term lease. C&P will move 500 employes to the building at Democracy Boulevard and Rte. I.

Joseph F. King, a real estate tax and accounting specialist, will speak at the luncheon meeting Wednesday of the Apartment and Office Building Association at the Mayflower hotel.

Weaver Bros. Inc., a mortgage banking firm, has opened a new office in Severna Park, Md.

KCE Structural Engineers has won a first place award from the Concrete Reinforcement and Steel Institute and the Consulting Engineers Council for work done on the new National Permanent Building at 18th Street and Pennsylvania Avenue NW.

The written examinations for real estate brokers and sales agents in the District will be held at 8:30 a.m. Tuesday at the National Guard Armory, 2001 East Capitol St. SE.