378 West End Avenue
Originally built in 1915, 378 West End Avenue in Manhattan underwent a substantial restoration and adjacent addition, resulting in a collection of one- to six-bedroom condominium units along West 78th Street between West End Avenue and Broadway.
The structural design connects a new cast-in-place concrete building to an existing steel and cinder-slab structure. The 13th-floor roof of the original building was removed and reconstructed at a lower elevation. A new, full-lot concrete slab at the 14th floor was added above the existing building, along with partial 15th and 16th floors. Below grade, two basement levels accommodate mechanical spaces, parking, and amenities including a squash court and lap pool.
| Client | Alchemy Properties Inc. (Owner) | iStar Inc. (Client) | Anna Zimmerman (Developer) |
|---|---|
| Architect: | COOKFOX |
| Size | 18 Stories | 190,000 SF (17,651 SM) | 68 Units |
| Sustainability | Green Roof, High-performance windows, Recycled materials |
| Office: | New York |
| Completion: | 2020 |
Excavating the cellar posed a technical challenge: two sub-grade levels were cut 30 feet into rock directly adjacent to the existing landmarked structure. DeSimone worked closely with the architect to adjust plans in response to field conditions uncovered during construction. Structural details were revised as needed to accommodate existing conditions.
At the eighth floor, ornamental balconies originally constructed in 1915 and later removed were reintroduced using cantilevered steel framing. The existing cinder slabs were structurally evaluated and either reinforced or replaced in select areas to meet required load-bearing criteria.
