If the sheer height of the 910-foot tower that’s proposed to rise at 50 First Street doesn’t wow you, the tower’s elevated first floor and open-air plaza beneath surely will. From John King with respect to the “gasp-inducing” design:
The lead architect for the project is Foster + Partners, the celebrated English firm doing the doughnut-shaped Apple headquarters in Cupertino. If built as now envisioned, the San Francisco tower would be equally futuristic, with brawny structural columns slicing across a mid-block space 80 yards wide. Except for the elevator lobbies at the rear of the plaza the tower would begin 70 feet in the air, clad in glass and held in place by diagonal columns forming giant X’s along the outer walls.
“The way you walk along and through that building will be different from anything that you’ve encountered before,” promised design director Stefan Behling of Foster + Partners, which is working on the project with local architecture firm Heller Manus. “The goal is that it will be fully public, open to the air. … A space of this scale has the potential to make people go ‘wow.’ “
Above the plaza, the lower 20 or so stories of the 50 First Street building would be 240 feet wide, “equal to the broad side of the slab towers at Embarcadero Center.” The tower would then taper so that the top is 25 percent more narrow than the bottom in order to meet planning requirements and “[keep] the building from casting excessive shadows on nearby public parks.”