public buildings

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adaptive use

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Tweed Courthouse
New York, NY
Client: NYC Economic Development Corporation

Project Type: Comprehensive Interior and Exterior Restoration; Feasibility study

The Old New York County Courthouse, better known as Tweed Courthouse, is one of the city’s grandest civic monuments.  Designed by John Kellum and Leopold Eidlitz and built between 1861 and 1881, the courthouse is the legacy of legendary Tammany Hall boss William M. Tweed.  The courthouse has retained its original spatial arrangement, encompassing thirty monumental courtrooms and a five-story central rotunda in 177,500 square feet of space.  The building was designated a National Historic Landmark in 1976.

Exterior, after restoration. Beginning in 1989, the building’s exterior was cleaned, each of the 10,000 stones were numbered and surveyed, and the exterior was completely restored. copyright Michael Rogol

As the first step in the restoration process, the firm prepared a comprehensive feasibility study for the exterior and interior spaces, documenting existing conditions and recommending procedures for restoration.  Following masonry cleaning, the team evaluated and recorded the conditions of more than 10,000 blocks of stone and all windows and doors. Interior studies included structural analysis, building code analysis research on the etched and stained glass rotunda skylight diffuser (removed during World War II), investigation of original decorative treatments, and mapping of original heating and ventilating ducts.

In the spring of 1999, JGWA began a complete restoration of the building, including extensive repairs to the exterior marble; a new metal roof; reconstruction of the monumental north portico staircase; a new rotunda skylight; restoration of doors, including providing historic hardware; replication of historic lighting; repair of ornamental cast iron elements; restoration of historic interior finishes; and new HVAC, plumbing, and electrical systems installed with only minimal intrusions on the historic spaces.

JGWA also directed an innovative restoration of Tweed’s open-cage, manually-operated elevators – the last of their kind in New York City – retaining the original appearance and operating mechanisms while installing modern operating and safety systems. 

Today the Tweed Courthouse is home to the NYC Department of Education and City Hall Academy.