Investors Stuart A. Bernstein and J. Mason have purchased the 145-apartment building called 4101 Cathedral Avenue (NW) from Catheral Parkway Associates and plan to convert it to cooperative ownership. The largest apartments in the 15-year-old building have three bedrooms and [WORD ILLEGIBLE] square feet of space. Bernstein and Mason were the ones who converted the neighborhood's Colonnade and enbriar apartments to condominion ownership.

Real estate condominiums and [WORD ILLEGIBLE] unit developments will be the topic of a course of study to be [WORD ILLEGIBLE] May 5-7 in Reston by the American Law Institute and the American Bar Association. For information, call Raymond Hart, associate director of the Committee on continuing Professional Education the ALA-ABA in Philadelphia (387-3000).

[WORD ILLEGIBLE] & Dunlop has arranged a million permanent loan for the [WORD ILLEGIBLE] section of the Patriot Village apartments in Annandale. Connecticut Mutual Life Insurance Co. is the owner. The Charles E. Smith Company developed the Patriot Village and complex; the 304-unit second [WORD ILLEGIBLE] was built by Richmarr Construction. When Completed, the complex will include 1,056 garden apartments.

[WORD ILLEGIBLE] Bottom Mews, a group of 14 traditional town houses, has completed on New Hampshire Avenue NW at 24th Street by the owner Co. Wellington Construction was the general contractor and [WORD ILLEGIBLE] Associates the architect. [WORD ILLEGIBLE] are priced between $140,000 to $150,000. Burr, Morris & Pardoe padling sales.

The Masonry Institute has elected Payne of Maryland Clay Products as President. Other officers are Albert [WORD ILLEGIBLE] Jr., James B. Mock, Kenneth [WORD ILLEGIBLE] and Peter B. Hoyt.

Eighteen persons will be admitted to the newly established Hall of [WORD ILLEGIBLE] of the National Association of [WORD ILLEGIBLE] Builders during the May 10 [WORD ILLEGIBLE] board meeting of NAHB here. [WORD ILLEGIBLE] and Urban Development Secretary Patricia Robert Harris will speak. Bas-relief portraits of the honoree will be displayed at the National Housing Center at 15th and M NW. Among those to be honored are Sen. John J. Sparkman (D-Ala.), former president of the Federal National Mortgage Association J. Stanley Baughman, and the late Edward R. Carr, a builder-developer here and a former NAHB president.

Donald R. Childress, formerly an executive with Panorama Properties, has opened his own realty firm, Aries Real Estate Corp., in McLean. Childress now is serving as first vice president of the Northern Virginia Board of Realtors and chairman of the legislative committee of the Virginia Association of Realtors.

The Alexandria Adult Education Education Program and the Northern Virginia Board of Realtors are offering a course in residential financing. For information, call 836-2812.

The third annual National Housing Management Conference will be held May 10-13 at the Sheraton Park. For information, call the National Center for Housing Management, (202) 872-1717.

Harlan C. Williams of Newark, Del., has been named the area representative on the newly established Realtor Energy Conservation Committee set up by Harry G. Elmstrom, president of the National Association of Realtors. The goal is to promote greater conservation of energy and natural resources by homeowners.

Kenneth Penrod and Bruce E. Stauffer have formed Penrod-Stauffer Building Systems, Inc., a team of design-and-build contractors serving this area. Offices are in Wheaton and Alexandria.

The Ryland Group has opened a new home homes park at Country Club Lake in Prince William County, Va., and another in the Owen Brown neighborhood of Columbia, Md.