Douglas Miner, formerly chief financial officer for Avis Enterprises in Detroit, has joined Holland & Lyons as a partner and vice president and chief operations officer. Miner will be responsible for condominium conversions, sales property management, restoration and general brokerage of the real estate development firm. It is based in the renovated powerhouse building at 3255 Grace St. NW in the Georgetown area, where several large residential-commercial projects are under way.

Henry M. Hall, a veteran of 27 years in sales and marketing with Gulf Oil Corp., has been named president of Venture Out in America Inc., a Gulf subsidiary. A new resident of Reston, Hall will be responsible for Venture Out's assets, sales and commercial property in three Florida locations and another in Mesa, Ariz.

District Realty Title Insurance Co. has named six area realtors and mortgage bankers to its advisory board: William Calomiris, John W. Gill, William S. Harps, Roger W. Hatch, Albert H. Small and Thomas M. Waish.

Don M. Sweet has been named vice president in charge of property management of Brannock Associates, a commerical leasing and management firm. Sweet, a certified property manager of the Institute of Real Estate Management, also lectures for the American Management Association.

John D. Tarpey has been named assistant sales manager for residential sales of Realty World-Glen J. Koepenick Inc., Rockville.

Broker Deane Maury, who recently won the designation of residential member of the American Institute of Real Estate Appraisers, has been named entertainment chairman for the convention of area realtors and mortgage bankers that begins June 22 at the Homestead.

Sen. John J. Sparkman (D-Ala.), who will retire this year after 44 years in Congress, will be honored June 20 at the Sheraton Park by the National Housing Conference.