In Metropolitan Pittsburgh Nonprofit Housing Corporation v. Board of Property Assessment, Appeals and Review, 480 Pa. 622, 391 A.2d 1059 (1978), the Supreme Court determined that the use of the homes was a charity and determined that it would be an unjustified extension of the constitutional concept of a purely public charity based strictly on age. The Court noted that whether an entity was a purely public charity did not depend solely on the age of those who lived in the housing project and benefited from the charity, and concluded that the Lemington Heights Housing Project was not a purely public charity because the federal government subsidized the mortgage interest payments to Metropolitan, and Metropolitan rented the units to low-income families who were approved by Housing and Urban Development (HUD) in accordance with a rent schedule established by HUD. the families who rented from Metropolitan also received rent supplement payments from HUD, and HUD paid annual real estate taxes. See also WRC North Fork Heights, Inc.