Kirby Building systems is part of NUCOR corporation. Kirby Building Systems ranks today as one of the top 10 manufacturers of metal buildings in the world, and is an industry-leading manufacturer of custom-engineered, high-quality and cost-effective metal building systems. With a tradition of excellence and industry experience dating back over 60 years, Kirby’s quality products include complete framing systems, wall and roof panel systems, and extended bay options – all engineered and manufactured by Kirby teammates.