Hersh Enterprises is gutting and reconstructing 34 apartments in a building formerly known as the Westerly at 1320 21st St. NW. Paul Hersh, president, said that the former rental building will be converted to condominium units ranging in proce from $30,000 to $80,000. Renamed the West End, the DuPont Circle area structure is expected to be ready to live in this summer.

The Coldwell Banker brokerage firm announced net income of more than $2.5 million in the quarter ending Dec. 31, the highest earning for a second quarter in the firm's history. The Washington office recently handled a $19 million transaction involving the sale of the Washington Industrial Parl on Lanham to two Allstate Insurance companies.

The Polinger Co. has been named management agent for the 1,250-unit Rotonda condominium complex at Tysons Corner. The firm also manages another large condominium complex, the Watergate at Landmark.

The District of Columbia Legislative Reporter will conduct a seminar on the Rental Housing Act of 1977 Feb. 9 at the Washington Hilton. For information, call 393-2202.

Information about evening real estate courses offered in February by Arlington County is available by calling 558-2581.

The Community Association Institute has regional workshops on condominium management and homeowner association problems, scheduled here Feb. 3 and 4. For information, call 223-6670.

McGraw Hill, Inc., has announced acquisition of Multi-List, Inc., a national firm that specializes in multiple listing information services for the real estate industry.