St. Louis City is independent from St. Louis County (since 1876). Building Division, 1200 Market St, Room 426. Missouri has no statewide building code. 70% of permits issued same-day; Hot Spot Desk Mon & Wed 9am–3pm. Online portal launched March 2026.
St. Louis electrical permit rules
St. Louis Building Division administers electrical permits under the 2017 National Electrical Code. Same-location same-type device replacement on existing wiring is permit-exempt. All new circuit installations, service panel changes, new hard-wired equipment, and EV charger installations require an electrical permit and a Missouri-licensed electrician. The Hot Spot Desk (Mon & Wed 9am–3pm) can process standard residential electrical permits same-day. Ameren Missouri provides electric service — utility coordination needed only for service entrance upgrades.
St. Louis's pre-1940 housing stock creates three legacy electrical conditions common in the city: knob-and-tube wiring (two-conductor, no ground, pre-1940 homes), 60-amp fuse service (common pre-1965, inadequate for modern loads), and aluminum branch wiring (1965–1973, requires specific connections). Any of these conditions discovered during a permitted electrical project should be assessed and documented. Many homeowners insurance companies require knob-and-tube assessment before extending coverage on pre-1940 St. Louis homes.
Three St. Louis electrical scenarios
| Electrical Work | Permit? | Est. Fee | St. Louis Note |
|---|---|---|---|
| New circuits / new wiring | Yes | ~$100–$300 | Missouri-licensed electrician; 2017 NEC |
| Panel upgrade or replacement | Yes | ~$200–$400 | Ameren Missouri coordinates meter base |
| EV charger (50-amp dedicated) | Yes | ~$150–$300 | Ameren TOU rates for overnight charging |
| Same-location fixture/switch/outlet replacement | No permit | $0 | Like-for-like at same location on existing wiring |
| Knob-and-tube assessment/remediation | Yes (if modifying) | ~$200–$500 | Insurance often requires; document findings |
Legacy electrical systems in St. Louis's older housing stock
Knob-and-tube wiring (pre-1940 homes) uses ceramic insulators to support bare copper conductors — a two-conductor system with no ground wire. Safe when original but risks arise when modified, covered with insulation, or overloaded by modern appliances beyond its original design capacity. Soulard, Lafayette Square, and many South St. Louis neighborhoods have K&T in many homes. Assessment by a licensed electrician is the starting point — some K&T can remain in service; portions that have been modified or overloaded should be remediated. The 60-amp fuse box (common in post-WWII tract homes built before 1965) cannot safely power a modern home's load — refrigerator, washer, dryer, HVAC, and kitchen circuits can exceed 60 amps simultaneously. Upgrading to 200-amp service is the standard recommendation and requires a permit and Ameren Missouri coordination.
What the inspector checks
Rough-in: wire gauge, support and stapling, box fill, panel work quality. Final: GFCI at bathrooms, kitchen countertops within 6 ft of sink, garages, outdoors; AFCI for 15- and 20-amp branch circuits per 2017 NEC; polarity and grounding; panel labeling. Call 314-622-3315.
What electrical work costs in St. Louis
Licensed electrician rates: $70–$105/hr. New dedicated circuit: $500–$1,400. Panel upgrade to 200 amps: $2,500–$5,500. EV charger: $700–$1,800. Kitchen circuits (2): $800–$2,000. Permit fees: $100–$400.
Does replacing a light fixture require a permit in St. Louis?
No — same-location same-type device replacement on existing wiring is permit-exempt. Installing a new ceiling fixture at a new location, running new wiring, or any panel modification requires an electrical permit and a licensed electrician.
What is knob-and-tube wiring and is it dangerous?
Knob-and-tube is a two-conductor electrical system (hot + neutral, no ground) using ceramic insulators in pre-1940 homes. It was safe when installed but risks arise when modified, covered with insulation, or overloaded. A licensed electrician can assess K&T condition. Many St. Louis homeowners insurance companies require assessment before extending coverage on pre-1940 homes.
How does Ameren Missouri work for St. Louis electrical upgrades?
Ameren manages the electric grid, service entrance from the street to the meter, and the meter. Standard electrical permit work (new circuits within existing service) needs no Ameren contact. Service entrance upgrades (100 to 200 amps) require Ameren to coordinate the meter base and transformer capacity. Contact Ameren at ameren.com.
What GFCI and AFCI requirements apply in St. Louis?
2017 NEC: GFCI required at bathrooms, kitchen countertops within 6 feet of sinks, all kitchen countertop receptacles, garages, outdoors, unfinished basements. AFCI required for all 15- and 20-amp branch circuits in dwelling units. Permitted electrical work must bring affected circuits into current 2017 NEC compliance.
Does a generator installation require a permit in St. Louis?
Yes — connecting a generator via a transfer switch requires an electrical permit and a licensed electrician. The transfer switch prevents dangerous back-feed to the Ameren Missouri grid. Never connect a generator directly to home circuits without a permitted transfer switch. Manual transfer switch: $700–$1,800 installed.
Is 60-amp fuse service dangerous in St. Louis?
Not immediately dangerous if properly fused, but inadequate for modern loads. Standard modern homes need 150–200 amps. Any St. Louis home with 60-amp service should prioritize upgrading to 200 amps — it's a safety upgrade, not just a convenience. Electrical permit required; Ameren Missouri coordinates the service entrance.
General guidance based on publicly available municipal sources as of April 2026. City of St. Louis uses 2018 IRC. Verify at 314-622-3315. For a personalized report, use our permit research tool.
Phone: 314-622-3315 (Hot Spot Desk: Mon–Wed 9am–3pm)
Hours: M–Th 8am–4:30pm, F 8am–4pm
Online: stlouis-mo.gov/building/permits
Codes: 2018 IRC · 2017 NEC · 2021 UPC · 2018 IECC
Cultural Resources: 314-657-3865 · Spire: spire.com · Ameren MO: ameren.com
Missouri One Call: 800-344-7483