§ 251. Policy and purposes of article. It is the policy of the state to promote the reconstruction and redevelopment of municipal urban renewal areas in a manner that will serve the civic, cultural and recreational needs of the community as a whole. There is need for local non-profit corporations to construct, with mortgage loan participation by the New York state housing finance agency and in furtherance of an urban renewal plan, civic, cultural and recreational structures and facilities and other capital development projects invested with a public interest, for the accomplishment of the purposes of article eighteen of the constitution and articles fifteen and fifteen-A of the general municipal law.