The Landmarks Preservation Commission on Tuesday approved United American Land’s application for 277 Canal Street — a 159-unit project at the corner of Broadway. SIGN UPThe project will include 31 affordable units. The rezoning was contentious: Backers argued that wealthy neighborhoods like Soho and Noho weren’t doing enough to add affordable housing, and that the addition of new supply (including market-rate units) would help ease costs. Critics argued that the plan may not produce as many affordable housing units as it proposed, and that new developments could displace existing rent-regulated apartments. The neighborhood plan is expected to produce 3,200 to 3,500 new housing units, including 900 permanently affordable ones.