Modernizing the United Nations General Assembly Building

Architects needed to reroof the distinctively concave roof of the UN General Assembly Building, and the redundant, robust SBS-modified bitumen system from Siplast will protect the Hall for years to come.

An international hub
The United Nations General Assembly Building of the UN Headquarters in New York City – built in 1952 – hosts the General Assembly annually in the General Assembly Hall. The building’s roof was past its useful service life, so Hoffman Architects worked with Siplast on the project.

Part of a $2.1 million dollar renovation project for the UN Headquarters included renovating the interior and exterior facade and reroofing of the General Assembly Building.

Security from above
Maintaining operations and accommodating the schedule of the General Assembly were just some of the challenges of the renovation project. The solution for the saddle-shaped roof starts with the existing lightweight insulating concrete deck, which is then covered by a nailable base sheet.

To ensure uninterrupted operations at the General Assembly Hall, the solution for the landmark building was Siplast SBS-Modified Bitumen Roof Systems. Two layers of Paradiene 20 base ply, followed by a Paradiene 30 FR TG granule-surfaced finish ply, were installed to the uniquely concave roof.

Facts: 

• 700 squares of two-ply SBS-modified bitumen roofing for a redundant and durable application
• The General Assembly Hall has a 1,800-seat capacity for the international delegates