Original design documents for the helical stair did not allow for a continual rise with a landing. Still, the team was able to reengineer the stringers to provide a final aesthetic to fit the space.

Designed to visually be a continual radial helical shape, the staircase had to include a landing within the stair to comply with the Americans With Disabilities Act.

Photo by Mark Andre, courtesy of Davis Construction

The solution required increasing the size of the stringers and modifying the location of the steel cross members to deliver the continual giant “swoop” look envisioned by the client and designers.

Overall, the approximately 200,000-sq-ft fit-out, completed at budget in January, consists of floors for both offices and amenity spaces, including conference space and terrace space, two full-service kitchens, a servery with radial stone counters and sneeze guards and a stand-alone radial multipurpose room.

The space features about 35,000 sq ft of imported marble office and conference fronts. 

The stone, which was fabricated in Italy from shop drawings, dictated both the wall layout and also the demountable joint layout. 

Photo by Mark Andre, courtesy of Davis Construction

Stone and marble shop drawings were submitted and approved prior to actual layout of the existing base building on site. Scheduling constraints forced the team to complete stone and marble alignment coordination during the shop drawing review process ahead of field verification. 

The alignments also needed to be maintained at metal base, glass joints, rail joints, demountable joints, zinc strips and polished concrete.

The demountable glass fronts on the second-floor conference rooms are made with bespoke radial termination points to complement the base building radial features.

Because all of the floors above the conference level border the curved atrium, the team had to create templates for the lighting fixtures to ensure that they would follow the radii of the walls. 

And because utilities and services for the multipurpose room are fed from below, the project team coordinated with the base building contractor on the interior design requirements for the slab. 

They included the size and locations of the embedded plates for connecting the steel superstructure and the sleeves for feeding ducts and the cables necessary for electrical, communications and sprinkler systems. 

These calculations had to be done early in the project because the base building contractor wanted to close in the acoustical drywall ceiling in the loading dock located below the multipurpose room.