HUD Secretary Patricia Roberts Harris and Senate majority leader Robert Byrd (D-W.Va.) will be the lead off speakers Sunday when the convention of the National Association of Home Builders gets under way in Dallas. More than 55,000 are expected for the four-day convention-exposition, one of the largest annual trade convocations held in the nation.

Caroline L. Campbell, a realtor in Great Falls, has been awarded the designations of certified brokerage manager and certified residential specialist by the National Association of Realtors.

Mimi Selig Homes, Inc., of Rockville, has opened a second office in Gaithersburg. Joseph Chabots is manager of the new office and Jeffrey Zellmer, vice president, has been named general sales director.

Charles V. Phillips Jr., immediate past president of the Suburban Maryland Home Builders Association, has been elected president of the Metropolitan Washington Builders Association and president of the Home Owners Warranty Corp. of the SMHBA.

Arthur C. Meuchaw, president of Standard Acoustics, Inc., has been installed as president of the D.C. Metropolitan Washington Subcontractors Association.

Richard C. Jaffeson has joined the American Institute of Planners here as coordinator for professional development.

Claxton Walker and William N. Papian will teach a course on home inspection techniques at Montgomery College for six sessions starting Thursday. Information is available from the college.

Robert L. Stout, a comercial loan officer at Walker & Dunlop, Inc., has been elected assistant vice president of the mortgage banking-real estate firm.