Engineering & architecture in O Fallon, IL
5 engineering & architecture listed in O Fallon, Illinois. 3 with a phone number and 5 with a website.
O Fallon accounts for 0.2% of the engineering & architecture listed in Illinois.
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Quick answer
O Fallon, IL has 5 engineering & architecture listed on USA Business Search. 3 list a phone number and 5 list a website. The most listings are in ZIP codes 62269.
Updated October 2026Fgm Architects (fgma)
Sitton Energy Solutions
Engsim Corporation
Sitton Consulting Group, Llc
How to choose an engineering firm in O Fallon
- Ask who will actually do the work and how often you'll hear from them.
- Get the scope, price and timeline in writing.
- Ask for two references from clients like you.
Check the business: confirm a company's registration with the state in our Illinois business lookup guide, and licensed trades in the contractor license lookup guide.
Common questions
How many engineering & architecture are listed in O Fallon, Illinois?
USA Business Search shows 5 engineering & architecture in O Fallon. 3 list a phone number and 5 list a website.
Which ZIP codes do these listings cover?
They include ZIP codes 62269.
How do I choose an engineering firm in O Fallon?
Ask who will actually do the work and how often you'll hear from them. Get the scope, price and timeline in writing. Ask for two references from clients like you. Check the license or registration through the Illinois business lookup guide.
How do I add or fix a listing?
Listings are free. Use Add your business, or the Claim or fix link on any listing.
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