Two-Story modular offices install quickly and reclaim wasted high ceiling space.br These custom designed two-story modular offices are engineered for years of use, you can relocate or expand your building as your needs change. br br Panel Built, Inc. is one of the fastest growing companies in the modular construction industry. From inplant offices to mezzanines to ballistic rated guard houses, we have one goal, "To Solve Our Customers Space Needs with Excellence and Great Customer Service.