Prost Builders has completed various projects with the Missouri State Capitol over the years. These projects include the North Plaza renovation, replacing the escalators and elevators, skylight replacement and/or restoration. Prost also completed the Environmental Control Center (ECC) chiller upgrades which provides cooling to the State Capitol, Supreme Court, Truman Building, and other State buildings. Other Capitol projects were the exterior stone terrace renovation around the Capitol. A current project is the 2 year long historic stained glass removal and restoration by stained glass experts in Los Angeles.