Building Permits in Missouri

We cover 29 cities in Missouri. Select a city below to see local permit requirements.

29 Cities Covered

3,058 Permit Rules

IRC Building Code Base

Building Codes in Missouri

Building permit requirements in Missouri are enforced at the local level — each city and county building department sets its own rules, fees, and timelines. Most cities in Missouri follow the 2018 IRC, though 1 city is still on the 2021 edition.

We cover 29 cities in Missouri with 3,058 specific permit rules. That's real, locally researched data — not generic advice. Each city page shows exactly what triggers a permit, what's exempt, estimated fees, and how to apply.

The bottom line: don't assume your city follows the same rules as the one next door. A fence that's exempt in one town might need a full permit two miles away. Always check your specific city.

Permit Fees Across Missouri

Across the 29 cities we cover in Missouri, permit fees range from $25 – $5,500. The average sits around $151 – $631.

Fees vary a lot by city and project type. A simple fence permit might run you $50, while a full room addition could be $2,000+. Most cities calculate fees based on your estimated project value — typically 1–2% of construction cost. Check the specific city page for accurate numbers.

Common Permit Exemptions in Missouri

These are the most common projects that don't require a permit across cities in Missouri. Keep in mind — "exempt from a permit" doesn't mean "exempt from code." You still have to build to code even without a permit.

Fence / Gate: Exempt in 60 of our 29 covered cities

Window / Door: Exempt in 47 of our 29 covered cities

Shed / Outbuilding: Exempt in 36 of our 29 covered cities

Swimming Pool / Hot Tub: Exempt in 31 of our 29 covered cities

Garage / Carport: Exempt in 30 of our 29 covered cities

Exemptions vary by city. Always verify with your local building department before starting work.

Contractor Licensing in Missouri

If you're hiring a contractor in Missouri, make sure they're properly licensed. You can verify credentials through the Missouri Division of Professional Registration.

Two rules of thumb: never pay a contractor in full upfront — a third down is standard. And if a contractor tells you "we don't need a permit for this," that's a red flag. Use PermitMint to verify before you sign anything.