All Cities / MO / St. Louis County
Permit Fees in St. Louis County, MO
✓ Verified from published fee schedule
Based on Department of Transportation and Public Works published fee schedule
Data last verified: March 16, 2026
CORRECTED - previously categorized as SINGLE_PERMIT but Chapter 1100 has separate sections for Mechanical (1100.140), Electrical (1100.190), and Plumbing (1100.200). Residential building fees in Table 1100.060 cover building inspections only.
Permit Cost by Project
Kitchen Remodel$417
Bathroom Remodel$388
Roof Replacement$173
Deck / Patio$173
Window Replacement$137
HVAC Replacement$94
Electrical Panel$94
Water Heater$47
Do You Need a Permit?
No — Paint, cosmetic updates, fixture swaps
Yes — Bathroom remodel ($388)
Yes — Kitchen remodel ($417)
Yes — Roof replacement ($173)
Yes — HVAC replacement ($94)
Yes — Water heater ($47)
Yes — Deck / patio ($173)
Yes — Window replacement ($137)
Yes — Electrical panel ($94)
Verified Permit Cost by Project Type
Kitchen Remodel
$417
Building: Table 1100.060 interpolated for $25K = ~$229. Plumbing and electrical at
Bathroom Remodel
$388
Building $200 + plumbing $94 + electrical $94 = $388. No plan review assumed for simple
Roof Replacement
$173
Table 1100.060: $8K valuation = $173 (includes processing
Deck / Patio
$173
Table 1100.060: $8K valuation = $173 (includes processing
Window Replacement
$137
Table 1100.060: $5K valuation = $137 (includes processing
HVAC Replacement
$94
Section 1100.160: Replacement of heating and AC equipment = $94 per unit (includes processing and 1
Electrical Panel
$94
Service up to 200A = $12 unit price, min $94 applies ($47 processing + $47
Water Heater
$47
Domestic water heater replacement = $47.00 flat fee (Table
Two Types of Permits
Building Permit
Structural & Major Work
Covers structural changes, additions, remodels, and major renovations. Required when you're changing the layout, load-bearing walls, or footprint of your home.
Usually pulled by: General contractor or homeowner
Trade Permit
Specialty Systems
Covers plumbing, electrical, HVAC/mechanical, and roofing. Required when you're touching water lines, wiring, ductwork, or roof structure. Most remodels need trade permits on top of the building permit.
Usually pulled by: Licensed trade contractor (plumber, electrician, HVAC tech)
Work that typically requires a permit:
• New construction (residential or commercial)
• Additions: garage, deck, porch, ADU, carport
• Expanding or demolishing an existing structure
• Swimming pool installation
• HVAC installation or replacement
• Adding, moving, or removing walls
• Roof installation or replacement
• Finishing a basement
• Solar panel installation
• EV charging station installation
• Generator installation
• Fence installation
• Siding installation
• Window installation or replacement
Work that usually doesn't need a permit:
• Painting interior or exterior walls
• Installing cabinets without changing the layout
• Replacing carpet or flooring
• Replacing fixtures in the same location
• Cosmetic updates (countertops, backsplash, trim)
• Landscaping and yard work
Rules vary by city. When in doubt, call your local building department before starting work.
Permit Cost Calculator · St. Louis County
$388
Verified total permit cost in St. Louis County
✓ Verified from Department of Transportation and Public Works published fee schedule
St. Louis County charges $200 for a typical building permit. That covers most home remodels. Add electrical plumbing and HVAC at $94 each and a bathroom hits roughly $388. I pulled these numbers from the Department of Transportation and Public Works. They use flat fees here. The amount doesn't change with project size.
St. Louis County Building Permit Fees
St. Louis County uses flat fees for their permits. A typical remodel runs $200. That number doesn't scale with the size of your job. Electrical permits cost $94, and Plumbing is the same. HVAC permits cost $94 too, and Roofing comes in at $173. Decks cost $173 as well. I had to dig through the Department of Transportation and Public Works site to compile this. The county doesn't publish one clean PDF. (This took cross referencing several pages on their site.) The fee structure is simpler here than in most places. No valuation calculations. No tiers. Just set amounts for common work. That can save you money on larger projects. But it means small jobs might pay a bit more proportionately. The calculator on this page adds it all up for you. It uses these figures to give a quick total. Don't rely on it alone though. Always confirm with the county. We track many cities. St. Louis County falls on the lower side for these costs. The flat fee approach is the reason why. Your contractor should include these numbers in the bid. Don't get surprised later.
Chuck’s Take
“I always add the permit costs into every bid. In St. Louis County that $200 building permit plus the trades adds up quick. Don't let it become a surprise at the end.”
Leonard “Chuck” Thompson, LC Thompson Construction Co.
What Needs a Permit in St. Louis County?
Many projects require a St. Louis County building permit. Bathroom remodels need the main permit plus trades. Decks require approval at $173. Roof replacements cost $173 too. Don't assume everything needs one though. Fences don't require a permit, and Solar is listed at zero dollars. Pools fall into the same category. I can't list every possible job here. Sheds and window replacements depend on the exact changes. Check with the Department of Transportation and Public Works. They'll tell you for your address. Skipping a required permit isn't smart. It creates problems down the road. You can't undo the work easily if they catch it.
Penalties for Skipping Permits in St. Louis County
Skipping a required permit in St. Louis County can get expensive fast. The county doesn't list exact penalty amounts online. But they do enforce the rules. You can't just pay the normal fee later. Retroactive costs add up. This creates headaches with lenders and title companies too. Nobody wants that during a home sale. I don't recommend taking the chance. The work must meet code either way. Pull the permit first. Check with the Department of Transportation and Public Works if you've unpermitted work already. They handle these cases directly.
How Long Is a Building Permit Good For in St. Louis County?
A building permit in St. Louis County doesn't last forever. The exact time period isn't published clearly online. Most counties set six months or one year. You can't let it expire without action. Renewal might be possible but you should avoid that situation. Start your project promptly after approval. Finish the work before the clock runs out. Check with the Department of Transportation and Public Works for your specific permit. They'll give you the current rules.
Who Pulls the Permit in St. Louis County?
Your contractor should pull the permit in St. Louis County. Not you. They know the process and take responsibility for inspections. Put it in the contract clearly. If they ask you to pull it that's a red flag. Homeowners can pull permits for their own work. Most people shouldn't on bigger jobs. The liability stays with whoever does the work. Confirm this before work starts. Don't leave it to chance.
Chuck’s Take
“I pull every permit myself. If a contractor wants you to do it walk away. One person needs to be responsible for the code and inspections.”
Leonard “Chuck” Thompson, LC Thompson Construction Co.
What Makes St. Louis County Permit Rules Different
St. Louis County takes a lighter approach on several projects. Fences don't need a permit here. Solar installations carry a zero dollar fee. Pools don't require approval either. The Department of Transportation and Public Works handles the unincorporated areas only. This creates quirks compared to nearby cities. Always confirm your exact jurisdiction first. Inside city limits the rules change completely. I had to check multiple sources to sort this out. The flat fee model and exemptions make it simpler than many counties we studied. But simplicity doesn't mean no rules. Know what applies to your address before you buy materials.
Quick Reference · St. Louis County Permit Requirements
| Homeowner Task | Permit? | Est. Cost |
|---|---|---|
| Paint interior / exterior | NO | Cosmetic |
| Replace flooring | NO | Cosmetic |
| Replace kitchen cabinets (same layout) | NO | Cosmetic |
| Swap a light fixture (same location) | NO | Cosmetic |
| Replace a water heater | YES | $47 plumbing |
| Add / move electrical outlets | YES | $94 electrical |
| Remodel a bathroom | YES | $388 building, plumbing, electrical |
| Remodel a kitchen | YES | $417 building, plumbing, electrical |
| Replace / repair roof | YES | $173 building |
| Build a deck or patio | YES | $173 building |
| Build a fence (≤6 ft) | NO | Typically exempt |
| Install solar panels | YES | — Solar / PV |
| Replace HVAC system | YES | $94 mechanical |
| Replace windows (new opening) | YES | $137 building |
∗ Costs are verified for St. Louis County, MO from published fee schedule. Always confirm with your local building department.
Frequently Asked · St. Louis County
How much does a building permit cost in St. Louis County?
A typical building permit costs two hundred dollars in St. Louis County. That's the base amount for most remodels. A bathroom project with electrical and plumbing reaches about three hundred eighty eight dollars.
Do I need a permit to replace a water heater in St. Louis County?
Yes you do. It requires a plumbing permit. That permit costs ninety four dollars.
How much is a plumbing permit in St. Louis County?
A plumbing permit costs ninety four dollars in St. Louis County. This applies to typical bathroom work. Add the building permit to reach the full project cost.
Do I need a permit to build a deck in St. Louis County?
Yes you need a permit to build a deck in St. Louis County. The fee runs one hundred seventy three dollars. The county checks for proper construction.
Do I need a permit for electrical work in St. Louis County?
Yes electrical work requires its own permit. It costs ninety four dollars. Your contractor should handle pulling this permit.
Do I need a permit in St. Louis County for a fence?
No you don't need a permit in St. Louis County for a fence. The county doesn't require approval or fees for them. This is one area where they keep the rules simple.
Cite This Data
David Olson. (2026). Building permit fees in St. Louis County, MO. PermitCalculator. https://permitcalculator.com/cities/st-louis-county-mo/
APA format
David Olson. “Building Permit Fees in St. Louis County, MO.” PermitCalculator. Accessed March 19, 2026. https://permitcalculator.com/cities/st-louis-county-mo/
Chicago format
Data Attribution