[fimiak]

Because the limiter is the increased space needed for extra elevator shafts, it is very easy to see why it hasn't happened. The towers that have gone up have very small footprints. This means there is not very much square footage per floor, compared to something like 1WTC or the Empire State Bldg. which are both massive. This means two extra elevator shafts, larger & restricted for tourist groups, could indeed require 4-5% of every floor's rentable space. Giving up that much of each floor is crazy, with office rents being so high in SF. This isn't even considering the fact that the penthouse office floor is the potentially biggest profit maker for the building. A smaller footprint also means less space on the obs. deck for potential tourists.

Look at how small these footprints are, Oceanwide Center doesn't even have space for interior elevators. SF Tower is the only one that could realistically have had an observation deck, had its main tenant not opted to take the penthouse. If a building is allowed to be built with a large footprint then it will be easier and more profitable to build an observation deck in the future, but skinny towers are bad for that model.

Prop M contributes to this problem by making building office space in SF more restrictive, and therefore more profitable for those who do get large buildings through, and thus more attractive than a tourist vista.