Room Addition Permit Requirements in Union, IL
Village of Union handles its own building permits (McHenry County only covers unincorporated areas, not incorporated villages). Building Inspector is available one hour per week, Tuesdays 3 PM to 4 PM. The village has not published its adopted residential code edition online; rules below use IRC 2021 as baseline (the most common adoption in the Chicago metro). No published fee schedule, no online application portal. Apply in person during Village Hall hours or email permits@unionillinois.org. Illinois state plumbing code (IDPH-licensed plumbers) and electrical licensing requirements apply regardless of local code adoption.
By Joey, Founder · Last verified April 18, 2026 · How we research →
When you need a Addition permit in Union
Any addition that increases the conditioned floor area of a dwelling requires a building permit in Union, IL under 2021 IRC R105.1, even small additions under 200 square feet. Verify with the Village Building Inspector at (815) 923-4153 (available Tuesdays 3 PM to 4 PM) before starting work.
Mid-size additions (201-500 square feet) require a building permit in Union, IL with full electrical, plumbing, and mechanical sub-permits under 2021 IRC. Verify with the Village Building Inspector at (815) 923-4153 (available Tuesdays 3 PM to 4 PM) before starting work.
Large additions over 500 square feet require a building permit in Union, IL with stamped structural plans, full sub-permits, and zoning review under 2021 IRC. Verify with the Village Building Inspector at (815) 923-4153 (available Tuesdays 3 PM to 4 PM) before starting work.
Room Addition Permit Costs: Union vs. Nearby
| City | Estimated Fee |
|---|---|
| Union | N/A |
| Chicago | $440 – $5,500 |
| Aurora | $340 – $4,250 |
| Joliet | $320 – $4,000 |
Fees shown are estimates based on local building code data. Actual fees may vary based on project scope and valuation. See all Union permit costs →
Zoning Considerations
Room additions typically require zoning review for setbacks, height limits, and lot coverage. Your addition must comply with your zoning district's building envelope requirements.
Estimated Project Timeline in Union
Here's a typical timeline for a room addition project in Union, IL:
Timeline is based on Union's typical about 2 weeks permit processing time. Actual timelines vary by project complexity, completeness of application, and current department workload.
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Frequently Asked Questions
Contact Union's building department for current Room Addition permit fee information. Fees typically vary based on project scope and valuation.
It depends on the specifics of your project. Some smaller Room Addition projects may be exempt from permit requirements, while larger ones typically require a permit. Use our free lookup tool to check your specific situation.
Working without a required permit in Union can result in fines, stop-work orders, being required to remove completed work, and complications when selling your home. It's always best to check first.
Typical approval time for Room Addition permits in Union is about 2 weeks. More complex projects may take longer if plan review is required.
Learn More About Room Addition Permits
Read our complete guide covering permit requirements, costs, common exemptions, and the application process.
Read Room Addition Guide →