New York, New York
One Wall Street
The repositioning of One Wall Street represents one of NYC’s largest office-to-condominium conversions, transforming 30 office floors into 566 residential units, expanding lower floors for modern retail space, adding six floors—including a rooftop pool—to the south tower, and breathing new life into the iconic building.
To achieve the desired six-floor vertical addition atop the south tower with the existing structure, we specified sustainable lightweight voided concrete slabs, which reduced the need to reinforce existing columns while still achieving the desired floor heights.
DeSimone’s structural interventions to this landmarked building carefully preserved its historic aesthetic while reconfiguring the steel structure as required to convert floors for residential use.
| Client | Macklowe Properties |
|---|---|
| Architect: | SLCE Architects |
| Size | 30 Stories | 1,600,000 SF (148,644 SM) | 566 Units |
| Sustainability | LEED Silver |
| Office: | New York |
| Completion: | 2022 |
We created double-height retail space by removing the existing third-floor concrete slab and adding a steel truss that transferred the lateral loads to a new shear wall system.
For the ground-floor retail atrium, we removed a single existing column supporting 26 floors above and devised a system to transfer the load to new supports. That required hydraulic jacking techniques to preload girders and prevent deflections during construction before building permanent structures.
