[mhays]

Construction guy here. Yes, ground conditions are a big factor in what gets built...anything's possible but it all affects the spreadsheets. And yes, Chicago seems to have a prevalence of bigger sites vs. Manhattan. While I don't know Chicago's parking requirements, anecdotally there seems to be a lot of it with most buildings, and that's a big reason why larger sites pencil. Low/zero parking ratios (as well as use of conveyance systems etc.) is a defining factor in Manhattan's ability to use tiny sites.