Updated Oct. 5 at 11:55 a.m.

The National Building Museum is closing while it undergoes three months of repairs to its ceramic floors.

December 2 is the last day visitors will have access to its numerous exhibitions depicting architectural greatness around the world before it reopens in spring, according to a press release. (A post on PoPville from the museum estimates an opening day in March).

The museum turns 40 next year, but long before it became a tourist attraction, it housed the headquarters of the United States Pension Bureau, commemorated Union soldiers, and served as a space for Washington’s political and social events, according to the National Building Museum’s website.

Before 1980, when the Pension Building — as it was originally known — became the National Building Museum, it was almost demolished and “was badly in need of repair” the museum’s site says.

Chloethiel Woodard Smith, in her 1967 report, “The Pension Building: A Building in Search of a Client,” argued that it should be converted to a museum of building arts. More than a decade later, Congress deemed it a national treasure and mandated the creation of the museum as a non-profit educational institution.

But despite minor fixes made over the years, the building’s historic 19th-century ceramic floor has not stood the test of time.

“It was a difficult decision for the Museum to close its doors, even for a short period,” says Chase W. Rynd, executive director of the National Building Museum in a press release. “But the scope and scale of this project required us to do so. This is a necessary investment in our historic building’s infrastructure and we look forward to welcoming visitors back this spring.”

Updates to the museum will create an easy to navigate space that includes a new ground-level classroom and visitor center.

Alan Karchmer: The Architects’ Photographer will open with the renovated building and the Architecture & Design Film Festival: D.C. will take place on March 26 and 29, along with two exhibitions soon to follow depicting guns in America and the border wall.

The museum has not yet announced an official opening date.

This story has been corrected to reflect the Building Museum’s history as a space for Washington’s social and political functions, not George Washington’s, as previously written.

This story first appeared on WAMU.