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600 Fifth Featured in Modern Steel Construction

January 30, 2026
600 Fifth / Square 487
Thornton Tomasetti’s renovation of 600 Fifth Street was featured in Modern Steel Construction in an article co-authored by Michael Cropper and Michael Wood.
600 Fifth in Washington, D.C. Thornton Tomasetti
The article examines how strategic integration of steel framing enabled major structural transformations.
600 Fifth in Washington, D.C. Thornton Tomasetti
The existing roof and penthouse roof slabs were removed, and three new occupiable floors are being added to the top of the building.
600 Fifth in Washington, D.C. Thornton Tomasetti
The structural scope included extensive modifications to the existing post-tensioned floor slabs and enlargement of concrete columns to accommodate new two-story retail spaces.
600 Fifth in Washington, D.C. Thornton Tomasetti
A system of tuned braced frames was provided to upgrade the existing structure’s lateral system while minimizing impacts on the existing pile foundations.
600 Fifth in Washington, D.C. Thornton Tomasetti

Thornton Tomasetti’s renovation of 600 Fifth Street was featured in Modern Steel Construction in an article co-authored by Michael Cropper and Michael Wood. 

The piece examines how strategic integration of steel framing enabled major structural transformations within an existing concrete-framed building – including a relocated elevator core, new lateral system and a multistory vertical expansion – while minimizing impacts to existing foundations and adjacent Metro infrastructure. 

Thornton Tomasetti served as structural engineer for the project, working with Rockefeller Group and Stonebridge, design architect Pickard Chilton, architect of record Kendall/Heaton Associates, and general contractor Clark Construction. 

Read the full article in Modern Steel Construction

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