Manufacturing Facilities Milan, Tennessee Ceco Door's corporate office is located in Milan, Tennessee, where Ceco Door operates one of the world's largest manufacturing and warehousing complexes for steel doors and frames. The plant is equipped with modern high-tech computer numerically controlled manufacturing equipment and high speed communications with our other facilities. This 500,000 sq. ft., state of the art facility includes warehousing for 25,000 steel doors and 200,000 steel frame components. Milan is also home of CExpress, Ceco's rapid door and frame shipment program. Just tell us What, Where and When and we'll have it there. Click here for more information about CExpress. Valle Hermoso, Mexico Ceco Door's 65,000 sq. ft, facility in Valle Hermoso, Mexico, produces standard and made-to-order doors to exacting tolerances.