For Custom Post-Frame Structures, Why O’Neil?
At O’Neil Building Systems, we believe “good enough” is never good enough. As a family-owned and operated company with more than 50 years of experience, we specialize in designing and building high-quality post-frame (pole-barn style) structures for residential, commercial, and agricultural clients across Illinois, Missouri, and the Midwest.
We treat every project as a blank canvas and an opportunity to create something unique. Our in-house team of designers, engineers, and builders collaborates with you to develop a plan that meets your needs, desires, and budget. We use only premium materials from trusted manufacturers, backed by some of the strongest warranties in the industry. From yardmen to carpenters to foremen, our craftsmen take pride in their work, ensuring your building is not just functional but also durable and beautiful.
We’re proud to be a Capital Development Board–approved builder, an approved supplier in Illinois, and to offer sealed structural drawings to satisfy municipality and building code requirements. With decades of experience navigating local codes, our engineering department knows how to get your building permitted and built the right way.
Team & Expertise
At the heart of O’Neil’s success is our people—and their cumulative experience is one of the biggest things that makes us distinct.
From design & engineering excellence to skilled craftsmen & project managers, our team’s experience ensures that your project is handled expertly from concept to certificate of occupancy.
Ready to build with
a team you can trust?
Let’s start a conversation about your project today.