Attorney Richard S. Ehrlich and his father, Melville, 75, are developing a complex of federally styled town house offices, called Jefferson Park, at Jefferson Street and Park Avenue in Rockville. Smith, Segreti & Tepper designed the structure, which is being built by Eichberg Construction. The $1 million project is expected to be ready in January.

The American Institute of Real Estate Appraisers will hold a seminar on appraising as a career for minorities at the National Housing Center, 15th and M streets NW, from 1 to 4 p.m. Friday.

House resale prices in Montgomery County increased by 16 1/2 percent in August over a year earlier, according to a study made by Rockville appraiser Alfred Jarchow. He said the median resale price in Augbust was $77,500.

The National Association of Real Estate Investment Trusts will hold a conference Wednesday through Friday at the Sheraton Park Hotel. Rep. John B. Anderson (R-Ill.), an announced candidate for president, will be the main speaker at a luncheon to be held Thursday.

Midlantic Mortgage Corp. has arranged $6 million in construction financing for a group of 36 luxury town houses on Union Street in Old Town Alexandria. National Capital Developers is sponsoring the project. Prices of the houses will range to $425,000.

Historic Takoma Inc. will sponsor an old house workshop from 9:30 a.m. to 2 p.m. Oct. 6 at the Takoma Park Municipal Building, 7590 Maple Ave. For information call 270-5348 or 722-0127.