Tenants of the Plaza West apartments at 1669 Columbia Rd. NW have purchased the 69-unit building for $1.5 million. The Plaza West Cooperative will include members who will buy shares costing $3,000 to $3,500 and pay a portion of the monthly expenses and total mortgage payment. Projected monthly charges are estimated to be $340 to $565, depending on the size of the individual unit. The District's "right to purchase" program has provided an initial $72,000 loan to make the purchase from former owner Howard Bernstein. The co-op association is headed by Ron Tucker.

John N. Gallagher has been elected president of the areawide Property Management Association. A property management executive with Shannon & Luchs, Gallagher succeeds Stanley Reid as president of PMA, whose 250 members are responsible for some 350,000 residential rental units and more than 55 million square feet of commercial space.

Tysons Realty, headed by Pauline Thompson, recently handled the sale of the Cavalier apartments in the City of Fairfax. Sidney Albrittain bought the property for $3 million from Cavalier Associates.

Stewart E. Duval has been elected president of MFE Inc.-McLeod Ferrara Ensign, an architectural and engineering firm in Chevy Chase. Duval succeeds William Ensign, who left the firm to serve as assistant architect of the Capitol.

The area chapter of the National Association of Independent Fee Appraisers has elected Frederick Vaughan as president. Other officers are John R. Glover, E. W. Peterson, Gregory Zuk, Pedro Gomez and Ross Haworth.

The Laurel branch of the Prince George's County Memorial Library System has designated February as energy month. A program on energy saving is scheduled Monday at 7:30 p.m. and another program on the basics of passive solar energy will be held Friday at 7:30 p.m. The public is invited to attend the sessions at the library at 507 7th St. Other programs will be scheduled later this month. For information, dial 776-6790.

Home Tech Systems Inc. which does housing consultant work, has named Michael Lennon as director of marketing and training. He also is senior building analyst with the firm based at 7315 Wisconsin Ave., Bethesda.

Sonnenblick-Goldman Corp. arranged permanent mortgage financing of $5.5 million for the Inn at Twin Knolls started at Routes 29 and 175 in Columbia. The Souza Companies is developing the 152-room hotel that will be operated by the Hilton Hotel system. Completion is scheduled late next year.

A new semester of evening courses in construction will be started next week at the Columbia Technical Institute in Arlington. Information is available by calling 920-8866.

A new edition of the 200-page New Settler's Guide has been published by Robert Minogue of Potomac. The Washington edition of the guide for house hunters contains maps and detailed information about area communities. Anyone interested in buying copies can call Minogue at (301) 299-7507.

The House and Condo Shoppers Guide, to help area house and condo buyers, will be published April 31, which subsequent issues published in July, October and December. The guide will be distributed free to all personnel offices of every government agency and military base, major corporations and associations in the area. It will also be distributed through People Drug Stores and to Fortune 500 corporations throughout the country, as well as foreign governments with major housing needs in the Washington area.

The Burke Kalt Partnership, an architectural and planning firm in Reston, won first place in the town house category for a design submitted in a state-wide residential passive solar design competition in Virginia. The winning entries are on display in the Jefferson building in Richmond through the end of February. Sponsors of the competition included Virginia associations of architects, home builders and solar energy firms. The Burke Kalt winning design featured greenhouses and skylights as means to save energy.