Ervin W. Ornstein, 87, who owned a construction company that built tracts of single-family homes in the Washington area from the 1940s to the 1960s, died March 29 at Georgetown Hospital of complications of surgery. He lived in Washington. Mr. Ornstein, a Washington native, graduated from the old Central High School, where he was a standout on the varsity basketball team and won interscholastic titles as a swimmer and a half-miler in track. He attended the University of Virginia for two years and then served in the Army during World War II. After the war, he attended Georgetown University, where he played on the first string of the varsity basketball team. Soon after he left Georgetown, he became a real estate developer, following in the footsteps of his uncle, Morris Cafritz, a Washington area commercial and residential builder and civic leader.