Photo by Lincoln Barbour

Installation of the 17-ft-long, 0.5-in.-thick, 4.5-ton steel plates for the stairwells required extensive custom engineering to support the steel blades’ weight. To maneuver the plates into the building and install them within the post-tensioned concrete slab, Swinerton built a gantry on the building exterior to set the treads and plinths. One of the fourth-floor windows was removed and an apparatus was built that extended out the 4-ft by 4-ft window and connected the gantry to the interior. This gantry would hoist an individual blade and rotate it horizontally, then the apparatus pulled it through the narrow window and dragged it to the correct location. The tallest blades of plate steel rise from the bottom of the fourth floor through the top of the fifth floor, where it acts as a guard rail.

Photo by Lincoln Barbour

Since Portland’s building codes have more stringent requirements than European codes due to its more seismically active region, the design had to be strengthened for seismicity. For example, each office is designed as a stand-alone room without a ceiling connection. But to meet Portland’s seismic criteria, each freestanding office had to move independently during an earthquake, which translated into integrating dozens of ties into the post-tensioned concrete slab.