The most controversial issues in the citys land use planning regard the future of the vast underutilized areas still zoned for industrial purposes. As housing developers scour the city for marketable, unencumbered sites and planners ponder where Manhattan can accommodate future commercial growth, large sections of the city remain off-limits to most types of new development because of its manufacturing zoning.

For several decades proposals to rezone manufacturing districts to allow other uses have run aground of opposition from border communities that prefer the tranquility of the status quo and from industrial preservationists who believe the city must retain a diversified, blue-collar job base. The decline of the citys industrial sector has thus far defied all efforts to arrest it, however, and there is an increasing consensus that the citys economic evolution has made strict segregation of residential, commercial and manufacturing uses obsolete.