Donald Trump administration says White House ballroom construction is a matter of national security 

In its filing, the administration included a declaration from the deputy director of the US Secret Service saying more work on the site of the former White House East Wing is still needed to meet the agency’s “safety and security requirements.” The administration has offered to share classified details with the judge in an in-person setting without the plaintiffs present.

The government’s response to the lawsuit offers the most comprehensive look yet at the ballroom construction project, including a window into how it was so swiftly approved by the Trump administration bureaucracy and its expanding scope.

The filings assert that final plans for the ballroom have yet to be completed despite the ongoing demolition and construction work. Below-grade demolition of the site continues, wrote John Stanwich, the Park Service’s liaison to the White House, and work on the foundations is set to begin in January. Above-grade construction “is not anticipated to begin until April 2026, at the earliest,” he wrote.

The National Trust for Historic Preservation, a privately funded group, is asking the US District Court to block Trump’s ballroom addition until it goes through comprehensive design reviews, environmental assessments, public comments and congressional debate and ratification.

Trump had the East Wing torn down in October as part of the project to build an estimated USD 300 million, 90,000-square-foot ballroom before his term ends in 2029.

The project has prompted criticism in the historic preservation and architectural communities, and among his political adversaries, but the lawsuit is the most tangible effort thus far to alter or stop the president’s plans for an addition that itself would be nearly twice the size of the White House before the East Wing’s demolition. A hearing in the case was scheduled Tuesday in federal court in Washington.