"We've been building dreams for over 50 years! Let us help build yours!"

Custom Designed Post-Frame Structures

O'Neil Building Systems specializes in custom built post-frame structures. Our team will work with you on the design, engineering, and construction of your post-frame structure. Our saying is, "If you can dream it, we can build it!" That's what we've been doing for the customers in Illinois, Missouri, and parts of the Midwest.
O'neil cartoon — Agricultural Buildings in Sauget, IL
House Surrounded By Trees — Agricultural Buildings in Sauget, IL

Why O'Neil

Do your dreams come in only one color or fit in a specific box? The answer is usually no. We approach every project the same way. We build a structure from the ground up, not using a "standard" design.

How We Build

You have the deciding power with what goes on your O'Neil Building. We'll take care of what goes into the building system. We combine fully engineered designs, quality materials, and great craftsmanship to create the custom-built structure that will be a source of pride for years to come.

Discuss your Project

Call O'Neil Building Systems at (800) 489-6533 and (618) 337-6100 to discuss your project needs and learn how we can help.