Financing for Montrose House, a 250-unit housing project for the elderly sponsored by the Greater Jewish Community Foundation of Washington has been arranged by American Development and Finance Corp. of Rockville. Harold L. Kramer, president of ADFC, which specializes in state and federal financing programs, said the loan was arranged with Riggs National Bank of Washington and the Community Development Administration of Maryland. The new housing will be located at the Jewish Community Center in Rockville.

The Northern Virginia chapter of the Associated Builders and Contractors recently installed Joseph L. Krewatch as president. Other officers are Fred W. Tropp, Robert A. Stevens, Walter C. Davis Jr. and Wade P. Whitener. Gregory J. Fitzgerald is executive director.

Dennis E. Mastie has been named sales manager of Sherman & Sheehan Real Estate Corp. in Alexandria. A navy veteran, he also served on the Alexandria police force before going into real estate several years ago.

Central Mortgage and Housing Corp. of Canada has retained Shannon & Luchs, Realtors here to set up an automated financial and real estate management system. It will provide financial and management information on some 11,000 rental units in the Montreal area.

Arlen Development Co. has announced the opening of another section of Maplewood Village townhouses, now being converted to condominium ownership in the Annandale area. In the Oakwood Village section, 103 townhouses were sold in six months. Potential purchasers are permitted to lease their units at reduced rentals until sales are completed.

A Soviet "work group" recently visited the new town of St. Charles, a development of 8,000 acres in the Waldorf area of Charles County, Md. The tour of U.S. new towns was sponsored by the Department of Housing and Urban Development.