Originally Posted by spacevator
I believe the height limit is to accommodate the view corridor of City Hall Tower as seen from the BFParkway. 1213 Walnut probably would be in the backdrop of views of City Hall Tower from the Art Museum, if there were no height limit there.
I've thought of that as well but it seems to be a little outlandish. Looking at Google Earth, 12th/chestnut, 11th/sansom, 10th/walnut, 9th/Locust would be the locations that a tall building would appear directly behind the City Hall tower in the view from the PMA steps. 1213 Walnut, if over 600 feet, would still end up being obscured by the Comcast Center (if my calculations are correct).