ABI Chelsea, 455 W. 19th Street

SGH provided construction engineering services and designed the cast-in-place concrete structure with flat-plate slabs, shear walls, and a pile-supported mat foundation. Highlights include:

• Designing a steel corbel system to cantilever over the secant pile wall to support ten-story concrete columns at the building’s property line
• Surveying adjacent properties to document conditions prior to construction and identify areas susceptible to damage from construction operations, including excavation, underpinning, concrete placement, and steel erection
• Monitoring vibrations and conditions at eleven properties within 90 ft of the project site
• Evaluating the structure to support a rooftop water tank
• Designing secondary steel framing to support precast concrete facade panels and windows for out-of-plane lateral loads and detailing connections between the secondary steel and the concrete slabs
• Analyzing the foundation for loads imposed by a crane on the sidewalk

We consulted on the design and helped select systems for foundation, below‑grade, wall, and terrace waterproofing; fenestration/curtain walls; and roofing. Highlights include:

• Developing details to integrate systems and create facade setbacks/projections
• Analyzing heat and moisture migration through the primary wall, roof, and window wall/curtain wall systems
• Reviewing concepts and shop drawings for prefabricated facade elements
• Evaluating energy code compliance

SGH provided structural and building enclosure construction-phase services, including reviewing submittals, observing ongoing work, and helping address field conditions.