Boris Lang, 81, formerly of Northeast Philadelphia, a real-estate developer and community activist, died of heart failure Dec. 9 at Craven Regional Medical Center in New Bern, N.C., where he had lived for the last two years.

For more than 45 years, Mr. Lang developed residential real estate in Maryland, New York and Pennsylvania. His projects included U.S. Housing and Urban Development funded housing in North and South Philadelphia, his brother Stu said.

In the 1980s, Mr. Lang was chairman of the board of Philadelphia Neighborhood Services Inc., a nonprofit that combats neighborhood deterioration by providing mortgages, rehabilitation loans and other services. As president of the Building Industry Association of Philadelphia in 1999, Mr. Lang secured then-Mayor Ed Rendell's support for the city's participation in a federal pilot program designed to bring market-rate construction to city neighborhoods. He was an active member of the National Association of Home Builders.

Mr. Lang was past president of Provident Savings and Loan Association and past vice president for government lending of Atlantic Financial Corp.

He graduated from Northeast High School and the Pennsylvania Maritime Academy. He served in the Navy at the end of World War II and during the Korean War.

He enjoyed sailing in Maryland.

In addition to his brother, Mr. Lang is survived by his wife of 62 years, Sonda Gewitz Lang; a son, Larry; daughters Betsy and Brooke; and a granddaughter.

Services were private.