Preservation Periodical: Volume 5, Issue 1
Winter 2026
Castle Corner
By Carly Bond
The Revitalize Castle project will rehabilitate the Smithsonian Institution Building (commonly known as the Castle), which is the Smithsonian’s first building and serves as its symbolic heart. The project includes exterior and interior restoration, the installation of new mechanical systems, seismic protection, and the construction of below-grade support spaces.
On March 29, 2023, a Programmatic Agreement was executed and amended on April 12, 2024, to conclude Section 106 consultation. As part of the project’s mitigation, the Preservation Periodical will feature Castle construction progress updates throughout the duration of the project, highlighting new discoveries related to the building’s history, historic function, and construction.
Upper Great Hall Revealed
In summer 2025 (Volume 4, Issue 2) of the Preservation Periodical, the Castle Corner covered the exposure of the profile of the Castle’s Upper Great Hall ceiling and its tripartite division, long concealed by a non-historic dropped ceiling.
Visitors to the Castle enter on the first floor into the Great Hall, a long double-height space originally used for exhibitions and staff. Directly above is the Upper Great Hall, a second double-height space that matched the footprint of the Great Hall below. In the 1970s a mezzanine level was added to the Upper Great Hall bisecting the double-height space to create two floors of staff offices. The Revitalize Castle project removes this non-historic infill and returns the Upper Great Hall interior to public programming and access.
Careful demolition work of the 1970s-era infill is nearing completion, revealing the full volume of the Upper Great Hall for the first time in almost 50 years. Previously the public was not able to access the third and fourth floor offices that infilled the Upper Great Hall. The 1970s-era infill created long east-west corridors with rows of single and double-stacked offices that blocked light and visibility to the corridors from the Upper Great Hall’s windows. Now that the mezzanine level and office partitions have been removed, the grandeur of the double-height space and full visibility of the tall lancet windows and west rose window have been restored. The transformation of the Upper Great Hall, even at this stage of construction, is already spectacular and gives a preview of the restoration work coming to the Castle.
