Modular-Office.com offers the highest quality modular building system in the industry. The National all steel super structure modular building system is designed for use in the most adverse industrial environments. With construction of 3" thick wall panels and a 26 gauge painted steel exterior and matching steel posts, on a polystyrene core, the Super Structure modular building system is available in stucco-embossed tan or gray, and a USDA smooth white. Options include 5/8" gypsum layers and kraft-honey-comb core and they can be manufactured in sizes up to 70' clear span.