New York, NY

88 and 90 Lexington Avenue


The condominium complex at 88 and 90 Lexington Avenue reinvents two adjacent rental properties as a single condominium building. SGH was the structural engineer for the renovation project.

SGH collaborated with the architect, Workshop APD, on this project to join a classically styled 1927 structure at 88 Lexington Avenue with the adjacent 1952 building. Highlights of our structural design include the following:

  • New foundations and steel framing to support a pool in the basement
  • Openings in the existing steel-framed and waffle-slab floor structures to accommodate new stairs
  • Cutbacks at the existing sloped roof on 88 Lexington for private roof terraces
  • Structural work for several modifications to 90 Lexington’s roof, including the following:
  • Support for three stories of mechanical equipment above the existing roof, strengthening existing columns and footings to support the increased loads, and new steel braced frames within the existing building to resist the added wind and seismic loads due to the new rooftop structure
  • New steel framing to extend the elevator to the roof level
  • Strengthening existing framing to accommodate assembly live loads at a rooftop terrace
  • Wall openings for new windows and attachments for a complete facade replacement at 90 Lexington

Project Summary



Completion Date
New Construction
Residential | Mixed-Use
HFZ Capital Group
Specialized Capabilities
Building Design

Key team members

Kevin Poulin
Kevin Poulin