⚡ Standby Generator permit in Missouri
A permanently installed standby generator with automatic transfer switch and fuel connection. Here is the Missouri-specific rule: who issues it, typical fees, timeline, go / no-go, and the official source to verify.
Standby Generator permit in Missouri
The Missouri rule for a standby generator, with fee range, timeline, go / no-go, and the official source.
Missouri
⚡ Standby Generator
Exact permit fees are set by the local building department. WikEst shows the published or code-based range where one exists, linked to its official source — verify the final amount at the source before budgeting.
⚡ Standby Generator permit fee in Missouri
Permit requiredGenerally allowedcity authority
Permit fee range
Electrical (and gas, if fuel-fired) permit fee set locally by the municipality.
Typical timeline
Varies by municipality — electrical/mechanical permits often same-day to 2 weeks.
Setback
—
Exempt if
Not size-exempt
A standby generator requires an electrical permit; fuel-fired units also need a gas/mechanical permit. Review NEC Art. 445 (Generators) and Art. 702 (Legally Required Standby Systems); verify load calc, transfer switch, and placement with your city.
Official sources: American Wood Council — Missouri Adopted I-Codes (local adoption; no statewide mandate) · City of St. Louis — Building Division
Representative cities for Missouri: St. Louis, Kansas City.
All 20 project fee ranges in Missouri
Official-source ranges where published; “By local jurisdiction” means no flat fee is published and the amount is set case by case.
| Project | Permit? | Authority | Fee range | Go / no-go |
|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | yes | city | Permit fees set locally by each municipality — verify with the city building department (St. Louis Building Division or KC Permits Division). | case-by-case |
| 🪵 Deck / Porch | conditional | city | Permit fees set locally by each municipality — verify with the city building department. | allowed |
| 🧱 Fence / Wall | conditional | city | Usually no building permit under the height threshold; zoning setback/height rules apply. Verify locally. | allowed |
| 🛖 Shed / Outbuilding | conditional | city | No fee under the exemption; a permit fee applies if over the local threshold. | allowed |
| 🪜 Basement Finish | yes | city | Building permit fee set locally; trade permits billed separately. | allowed |
| 🚗 Garage / Carport | yes | city | Building permit fee set locally; zoning clearance may be required first. | allowed |
| ☀️ Rooftop Solar PV | yes | city | Electrical/structural permit fee set locally by the municipality. | allowed |
| 🌡️ HVAC Replacement | yes | city | Mechanical permit fee set locally by the municipality. | allowed |
| 🍳 Kitchen Remodel | yes | city | Building permit fee; trade permits (plumbing/electrical) billed separately. | allowed |
| 🛁 Bathroom Remodel | yes | city | Building permit fee; trade permits (plumbing/electrical) billed separately. | allowed |
| 🏗️ Room Addition | yes | city | Building permit fee based on valuation; zoning and plan review apply. | allowed |
| 🪟 Window / Door Replacement | conditional | city | Permit fee if changing the opening; in-kind swap is often exempt. | allowed |
| 🏘️ Roof Replacement | conditional | city | Roof-covering permit fee set locally; in-kind re-roof may be exempt. | allowed |
| 🅿️ Driveway / Parking Pad | conditional | city | No building permit for private flatwork; a right-of-way/curb cut needs a separate permit. | allowed |
| 🏊 Swimming Pool / Spa | yes | city | Building permit fee; barrier fencing required by code. | allowed |
| 🧱 Retaining Wall | conditional | city | No fee under the exemption; a permit applies if over the threshold. | allowed |
| 💥 Demolition / Teardown | yes | city | Demolition permit fee set locally by the municipality; verify with the city building department. | allowed |
| 🚰 Septic System | yes | state | Onsite sewage construction permit fee set by the MO DHSS Onsite Sewage Program; verify with the program (573-751-6095). | allowed |
| 🔌 EV Charger | yes | city | Electrical permit fee set locally by the municipality. | allowed |
| ⚡ Standby Generator | yes | city | Electrical (and gas, if fuel-fired) permit fee set locally by the municipality. | allowed |
Missouri rule at a glance
Needs permit
yes
Issuing authority
city
Typical fee
Electrical (and gas, if fuel-fired) permit fee set locally by the municipality.
Typical timeline
Varies by municipality — electrical/mechanical permits often same-day to 2 weeks.
Setback
—
Exempt if
Not size-exempt
A standby generator requires an electrical permit; fuel-fired units also need a gas/mechanical permit. Review NEC Art. 445 (Generators) and Art. 702 (Legally Required Standby Systems); verify load calc, transfer switch, and placement with your city.
Official sources for this rule: American Wood Council — Missouri Adopted I-Codes (local adoption; no statewide mandate) · City of St. Louis — Building Division
Frequently asked questions
Does a standby generator need a permit in Missouri?
In Missouri, a standby generator is generally required to have a permit. Issuance is at the city level. Confirm the exact threshold with the local building department using the sources on this page.
Who issues the standby generator permit in Missouri?
Missouri permits for this project are handled at the city level — usually the city or county building department. Use the county permit authority lookup to find the exact office for your property.
How much does a standby generator permit cost in Missouri?
Fees are set locally in Missouri and are not a single statewide number. Open the official authority link on this page for the current schedule.
What exemptions apply to a standby generator in Missouri?
Baseline exemptions (e.g. small detached structures, low decks) may apply but Missouri or your city can amend them. Verify with the local building department.
🗺️ All projects in Missouri
The full Missouri permit guide across 20 home projects.
📊 Standby Generator in every state
Compare the standby generator rule across all U.S. states.
Standby Generator in other states
| State | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| California | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify setback and fuel-line rules with the city building department. |
| Texas | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Florida | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| New York | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Pennsylvania | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality (e.g., Philadelphia L&I). |
| Illinois | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality (e.g., Chicago DOB). |
| Ohio | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality (e.g., Columbus BZS). |
| Georgia | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department (e.g., Atlanta Office of Buildings). |
| North Carolina | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality. |
| Michigan | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality (e.g., Detroit or Grand Rapids). |
| New Jersey | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the local Construction Code Official. |
| Virginia | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Washington | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Arizona | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the issuing city. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify setback and fuel-line rules with the city building department. |
| Massachusetts | Conditional | city | Mechanical and/or electrical permit fee set by the city. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (NEC Articles 445/702) covering the transfer switch, gas/propane line, and connection. Verify with your local building department. |
| Tennessee | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Indiana | Conditional | city | Mechanical and/or electrical permit fee set by the local building department. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (NEC Articles 445/702) covering the transfer switch, gas/propane line, and connection. Verify with your local building department. |
| Maryland | Conditional | city | Mechanical and/or electrical permit fee set by the city. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (NEC Articles 445/702) covering the transfer switch, gas/propane line, and connection. Verify with your local building department. |
| Wisconsin | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipal building inspection department. |
| Alaska | Conditional | city | Mechanical/electrical permit; fee set by the municipality. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. Cold-climate starting provisions are reviewed. |
| Alabama | Conditional | city | Mechanical/electrical permit; fee set by the city. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Arkansas | Conditional | city | Valuation-based; Little Rock minimum building-permit fee $50 (work over $5,000 or requiring inspection). | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Colorado | Conditional | city | Mechanical/electrical permit; fee set by the city/county. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. Mountain/WUI communities may add fire-safety siting rules. |
| Connecticut | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Delaware | Permit required | county | Electrical (and often mechanical/gas) permit fee set by the county (unincorporated) or city. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify setback and fuel-line rules with the county/city building department. |
| Hawaii | Conditional | county | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Iowa | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Idaho | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Kansas | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Kentucky | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Louisiana | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Maine | Permit required | city | Electrical (and gas, if fuel-fired) permit fee set by the municipality. | Electrical/mechanical permits often issued same-day to 2 weeks. | Generally allowed | A standby generator requires an electrical permit; fuel-fired units also need a gas/mechanical permit and combustion/venting review. Maine requires licensed electricians and plumbers. Review NEC Art. 445 (Generators) and Art. 702 (Legally Required Standby Systems); verify placement, load calc, and transfer-switch wiring with the local inspector. |
| Minnesota | Permit required | city | Electrical (and gas, if fuel-fired) permit fee set by the municipality. | Electrical/mechanical permits often issued same-day to 2 weeks. | Generally allowed | A standby generator requires an electrical permit; fuel-fired units also need a mechanical/gas permit. Review NEC Art. 445 (Generators) and Art. 702 (Legally Required Standby Systems); verify load calculation, transfer-switch wiring, and placement with your municipal building department. |
| Mississippi | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply. |
| Montana | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply. |
| North Dakota | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply. |
| Nebraska | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply. |
| New Hampshire | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| New Mexico | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Nevada | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Oklahoma | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Oregon | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Rhode Island | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| South Carolina | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| South Dakota | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| Utah | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Vermont | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority where enforced. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line) where enforced. Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
| West Virginia | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |
| Wyoming | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city where enforced; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context) where a building department enforces. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |