Updated

Federal mismanagement of the construction of the Department of Homeland Security's new headquarters has delayed the project by over a decade and helped raised its cost by over $1 billion, according to a new watchdog report.

The nonpartisan Government Accountability Office released the report Friday ahead of an oversight hearing by the House Committee on Homeland Security.

The new headquarters for the DHS is being constructed at St. Elizabeths Campus, a former government mental hospital in Washington, D.C., that has been vacant for years.

The site was initially designated in 2006, as part of an effort to save money, and drastically consolidate the sprawling network of DHS locations. As of this summer, DHS workers were located in "94 buildings and 50 locations," according to the report, over roughly 9 million square feet of government-owned or leased property.

DHS wanted to move about 14,000 workers to the new headquarters and ultimately save money in the long run by cutting down on leased office space. According to the project’s website, the new headquarters will consolidate the DHS’ current facilities into a more “unified, secure campus.”

However, the project has run into serious problems under the leadership of DHS and the General Services Administration.

According to the GAO, the cost of the project have risen “by over $1 billion — from $3.3 billion to the current $4.5 billion.” Additionally, the project’s scheduled completion has been delayed “by over 10 years, from an original completion date of 2015 to the current estimate of 2026.”

The GAO blames the project’s woes on the DHS and GSA’s planning for the project, saying it "does not fully conform with leading capital decision-making practices intended to help agencies effectively plan and procure assets."

Among other issues, the report said managers did not always obtain "department-level approval of certain documents" and suggested their ongoing and ever-changing cost and schedule estimates are fundamentally flawed.

"Pending the development of reliable cost and schedule estimates, the project risks potential cost overruns, missed deadlines, and performance shortfalls," the GAO said.

The watchdog recommended that the DHS and the GAO revise the plans for the headquarters in order to reflect better practices, and that Congress require the agencies do so in order to receive funding for the project in the future.

In response, the GSA said it is developing “specific actions” to address the recommendations made in the report and is confident the actions will “satisfactorily remedy the concerns raised by GAO.”