St. Louis City is independent from St. Louis County (separate since 1876). Properties within city limits use this Building Division; county municipalities have separate permit offices. Missouri has no statewide building code. New online permit portal launched March 2026 enables 24/7 electronic submission.
St. Louis bathroom remodel permit rules — the basics
St. Louis follows the 2018 IRC cosmetic exemption: tiling, painting, cabinets, countertops, and same-location fixture replacement require no permit. The 2021 Uniform Plumbing Code (adopted February 2023) governs plumbing permits — a distinction from the IRC plumbing provisions used in most other cities in this guide. For homeowners, the practical result is the same: drain relocation and new supply connections require a plumbing permit and a licensed plumber.
St. Louis's most important bathroom-specific concern: lead paint. Most city residential properties pre-date 1978 when lead paint was banned. The EPA's Renovation, Repair and Painting (RRP) Rule requires that contractors performing renovation work disturbing 6 or more square feet of painted surface in pre-1978 homes must be EPA RRP certified or work for a certified firm. For bathroom remodels involving demolition to the substrate, this is federal law — verify any contractor's EPA RRP certification before hiring.
St. Louis's wood-frame floor system (most pre-1960 homes have basement access, not concrete slabs) means bathroom drain relocation typically involves basement plumbing work rather than slab cutting. The plumber accesses the cast-iron drain stack from below and connects new rough-ins — far simpler than Chandler's slab-cut approach.
Three St. Louis bathroom remodel scenarios
| Work | Permit? | Est. Fees | St. Louis Note |
|---|---|---|---|
| Tile, paint, cabinets, countertops | No permit | $0 | Pre-1978 homes: EPA RRP Rule for contractors |
| Same-location fixture replacement | No permit | $0 | Check cast-iron drain condition in old homes |
| Toilet/shower/sink relocation | Plumbing permit | ~$100–$200 | 2021 UPC; basement access in most older homes |
| New circuits / GFCI | Electrical permit | ~$100–$200 | 2017 NEC; Ameren Missouri |
| New exhaust fan/duct | Mechanical permit | ~$75–$150 | Route through exterior wall |
| New bathroom addition | All four permits | ~$300–$550 | Cast-iron stack connection from basement |
Lead paint — St. Louis's defining bathroom remodel concern
St. Louis's housing stock is among the oldest in this guide. Most city residential properties were built before 1978, when lead paint was banned. The EPA's RRP Rule requires that contractors performing renovation work disturbing 6+ square feet of painted surface in pre-1978 homes must be EPA RRP certified (or work for a certified firm). This is federal law — violations carry substantial EPA penalties. Verify any contractor's EPA RRP certification before hiring for work in an older St. Louis home. For owners performing their own work in their own home, the certification requirement doesn't apply, but safe work practices (wet sanding, containment, HEPA vacuum, proper disposal) are strongly recommended.
St. Louis has historically high childhood blood lead levels — a direct consequence of its aging housing stock. Lead paint in bathroom renovations is a genuine public health concern, not a bureaucratic formality.
What the inspector checks
Plumbing rough-in (per 2021 UPC): drain slope, trap, vent, supply routing. Electrical rough-in (per 2017 NEC): GFCI at all bathroom outlets. Mechanical: exhaust fan duct routing and exterior termination. Final inspections each trade. Call 314-622-3315.
What a bathroom remodel costs in St. Louis
Cosmetic refresh: $5,000–$11,000. Moderate renovation with plumbing changes: $14,000–$28,000. Full gut renovation: $20,000–$42,000. New bathroom addition: $14,000–$26,000. Permit fees: $150–$550.
Does retiling a bathroom require a permit in St. Louis?
No — the 2018 IRC exempts "painting, tiling, carpeting, cabinets, countertops, interior wall, floor or ceiling covering, and similar finish work." Tiling is directly stated as permit-exempt. If substrate modification (not finish tile) is involved, call 314-622-3315.
What is the EPA RRP Rule and does it apply to St. Louis renovations?
Federal rule requiring contractors to be EPA RRP certified for renovation work disturbing 6+ sq ft of painted surface in pre-1978 homes. Most St. Louis City homes pre-date 1978 — this rule applies to the vast majority of contractor-performed bathroom renovations. Verify contractor certification before hiring.
Does St. Louis have wood frame floors or concrete slabs?
Most pre-1960 St. Louis homes have wood-frame floor systems with full basement access — not concrete slabs like Chandler or Reno. Drain relocation typically involves basement access to the cast-iron drain stack. The plumber works from below to connect new rough-ins — no concrete cutting needed.
What is the 2021 Uniform Plumbing Code?
St. Louis adopted the 2021 UPC in February 2023, replacing IRC plumbing provisions. It covers the same general scope (drain, waste, vent, supply) as IRC plumbing but with different section references. Licensed St. Louis plumbers are familiar with both. For homeowners, the practical requirement is unchanged: plumbing changes require a permit and a licensed plumber.
What utilities serve St. Louis for bathroom permit work?
Spire (formerly Laclede Gas) provides natural gas. Ameren Missouri provides electric service. For standard bathroom trade permits (new circuits, drain relocations), no utility coordination needed. Utility involvement is only needed for service-level changes.
Is St. Louis City different from St. Louis County for bathroom permits?
Yes — independent city. Building Division (314-622-3315, City Hall Room 426) serves city addresses only. County municipalities have separate permit offices.
General guidance based on publicly available municipal sources as of April 2026. City of St. Louis uses 2018 IRC. Pre-1978 homes: EPA RRP Rule applies to contractor work. Verify current requirements 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 Office: 314-657-3865
Spire (gas): spire.com · Ameren MO: ameren.com · Missouri One Call: 800-344-7483