Welcome to the Broad Building Supply website! We are an independent locally owned wholesale millwork distribution center located in Columbia, MO. We specialize in interior and exterior door units, as well as a multitude of other millwork items. Deliveries are made on our own fleet of trucks to lumber yards and home centers throughout Missouri, Western Illinois and Eastern Kansas. While other distributors use millwork as an "add-on" item, at Broad Building Supply, "Millwork is our Specialty, not a Sideline". Give us a call!