Fast-paced construction within a dense urban environment like New York City has several distinctive rationales, approaches, constraints, and requirements for careful coordination. The fundamental principle that drives the need for speed in construction is economic. The sooner a new building is completed and put into operation, the lower are the carried financing costs and the sooner the project can recapture generated revenue streams. There are numerous approaches and structural systems that can speed up the construction process. This article focuses on characteristics of flat plate concrete systems which, when floor plates are repetitious and identical, can achieve fast superstructure builds by using a 2-day concrete placement cycle. However, in tight urban locations, spatial constraints for staging, installations, material, and labor, as well as complexity of architectural/design coordination, can potentially interrupt the cycle and cause delays. Instant communication and in-the-field coordination are key to maintaining the fast paced schedule and to minimizing mistakes. The structural engineer needs to be fully immersed in the day-to-day construction process to ensure successful and timely completion of the project.
We present case studies of three projects in New York City to illustrate coordination issues that are particular to this type of construction: Avalon West Chelsea, 41-42 24th Street (aka “QLIC”), and 150 Charles Street. These developments are primarily multi-family residential, but also feature street-level retail, at- and below-grade parking, and amenity features at upper levels including planted green roofs and terraces. Both Avalon West Chelsea and QLIC are rental buildings that required high-speed construction. In contrast, 150 Charles Street is a luxury condominium development.