At O’Neil Building Systems, we don’t think you should have to settle for ‘basic’ just to save a little money. For over 40 years, we’ve been custom builders of high quality, post-frame structures for residential and commercial customers in Southern Illinois, Missouri, and all over the Midwest.

We approach each project as a blank canvas and a world of potential. Our talented staff includes design, construction, and engineering professionals who will work with you to create a structural plan that meets your needs, desires, specifications – all within your budget.

The structural materials and components we use to create your building are of the highest quality, from trusted, world-class manufacturing partners, and are backed by some of the strongest warranties in the industry.

And our construction craftsmen – from the yardmen to the carpenters and foremen – all take pride in helping to create a building that you’ll own with confidence and satisfaction for years to come.

So whether you want a home, a commercial building, a building for extra storage, or a pole barn, O'Neil Building Systems can meet your needs.

  • O’Neil is a Capital Development  Board approved builder?
  • We’re an approved supplier for the  state of Illinois with over 40 years of  experience?
  • Our Engineering Department can  supply you sealed structural drawings, if needed?
  • We’ve got decades of experience  satisfying municipality requirements  and building codes throughout southern Illinois and the entire Midwest?
Still have questions? Contact Us
and we’ll be happy to give you all
the answers you need.