The Judges in the 2015 Engineering Excellence Awards Competition have selected Avalon West Chelsea for a 2015 ACEC New York Platinum Award in the category of Structural Systems.
Avalon West Chelsea is a new 588,000 SF, “L-shaped” multi-family residential development located at the corner of 28th Street and Eleventh Avenue, in the prime Chelsea Arts District of Manhattan, New York. Programmatically, this building consists of two distinct components: “Avalon West Chelsea,” a 31-story tower featuring 309 luxury apartments, and “AVA High Line,” a 14-story mid-rise that extends from the tower at west to the High Line Park at east, housing 405 units geared toward a younger market. The LEED silver property also includes roof-top terraces, rear yards, a fitness center, lounge areas, a 140-car parking garage, and retail at street level.
The building’s primary structure is cast-in-place flat plate concrete floors . Over 1,000 piles support almost 200 columns that range from one story to thirty-one stories, as well as seven sets of shear walls at core locations.
As the lateral resistance capacity of the foundation is concentrated under the tower portion of the building, the structure was engineered in such a way that the 575-foot-long rigid floorplates without expansion joints allow the mid-rise portion of the building to “cantilever” laterally from the high-rise portion.
The Client demanded a very fast and efficient construction process and this primary criterion drove the innovation in structural design. Applying this principle to a building of such large scale presented opportunities to find straightforward solutions to complex challenges. With engineers and in-house special inspectors on site, the design team, construction management and contracted trades were highly coordinated and able to resolve problems without delaying the schedule. For example, at locations where rebar was not installed to engineered specifications, a fiber reinforced polymer — typically used to repair old bridges — was used to reinforce concrete after it had cured. This tactic allowed the concrete construction to continue, and in turn allowed the subsequent trades to maintain the speed of construction.
The combination of innovative approaches to simplify structural systems, value engineering of methods to be employed, and a highly coordinated design team delivered a superior product to the client within budget and on time. Excavation and foundations cost approximately $12,000,000 and superstructure was completed at a cost of $27,340,000, or approximately $46 per square foot of superstructure.
Avalon West Chelsea serves as a testament to excellence of execution. While engineering is often lauded for achieving wild architectural forms, this project instead presents the value that thoughtful structural design brings to an immense construction, simplifying construction processes and focusing a potentially overwhelmingly unwieldy product into a straight-forward efficient production.