A federal agency has given the go-ahead for a $20 million project to renovate and expand a commercial inspection building at the Peace Bridge Plaza.

The federal General Services Administration last week completed a required environmental review of the project to revamp an existing customs office and warehouse building that provides space for inspecting trucks and agricultural products.

The review will allow the modernization of the 60-year-old building to move forward in an “expedited manner,” Sens. Charles E. Schumer and Kirsten E. Gillibrand said in a joint statement.

The project, which will be paid for by the Peace Bridge Authority, will completely renovate the interior and exterior of the building and add a 20,800-square-foot addition on its south side. The building’s footprint will remain within the existing Peace Bridge Plaza area.

The building, first constructed in 1952 and expanded in 1979, houses offices and space for the U.S. Food and Drug Administration, U.S. Customs and Border Protection, U.S. Department of Agriculture and U.S. Customs and Immigration Enforcement, in addition to private customs brokers.

The expansion will allow federal inspectors to locate their offices within the building, reducing the amount of time trucks have to wait for the inspectors to arrive, according to the GSA review.

A copy of the report was provided by the office of Rep. Brian Higgins, who had advocated for the federal agency to complete its review so the project could move forward.

The renovations will also include a new heating, ventilation and air-conditioning system, as well as electrical updates and roof-mounted solar panels intended to make the building more energy-efficient, according to the GSA.

Construction is expected to start in the fall of 2013 and would be done in phases over a two-year period.

The GSA’s review, completed Thursday, found that a more extensive environmental assessment of the project to renovate the commercial inspections building was not necessary. The project is not part of a plan to expand the plaza for the Peace Bridge