> There's hardly a plot of land available in Manayunk

Most of Manayunk is zoned for rowhomes only, with height limits. Developers would love the ability to build up on existing rowhome lots, with apartments, but cannot do that because zoning bans them from doing so. But as there is high development in the neighborhood, the developers still want to build, and thus are forced to do it on the only place it is legal to build apartments