lots and lots of historic districts there are crippling height restrictions all over the place, and you have to buy un-used "air rights" from your neighbors to

lots and lots of historic districts there are crippling height restrictions all over the place, and you have to buy un-used "air rights" from your neighbors to build anything taller than what already exists in the neighborhood environmental impact studies (weirdly) can be used against projects local "community boards" have a lot of power and the aforementioned centrally imposed limits on development -- the city's top-level boards may not like what you're doing to transportation