Do You Need a Permit for a Tub-to-Shower Conversion?

Short answer: usually yes. Most cities that publish bathroom rules require a permit once you remove the tub or enclosure, install a shower pan, or change the drain or valve. Swapping a toilet or sink in the same spot often doesn't need one.

The tub is scratched, the faucet drips, and the contractor says a walk-in shower will open the room and cost less than a full bath remodel.

Then someone asks the question that stalls the dumpster: do you need a permit for a tub-to-shower conversion? In many cities the answer is yes once the enclosure comes out, a new pan goes in, or the drain and mixing valve change — even if the toilet and vanity stay put.

Our bathroom remodel guide covers the broad line between paint-and-tile cosmetics and a permitted remodel. This article focuses on the specific project of removing a bathtub and installing a shower: what cities publish about when a permit is required, what sizes and valves they expect, how shower-pan tests work, which inspections to schedule, and when accessibility, HOA rules, or whole-house fixture upgrades ride along with the permit.

We read published bathroom and shower handouts from Menifee, Pasadena, Pleasanton, Sacramento, San Bruno, Foster City, and Rancho Palos Verdes in California; Austin, Texas; and North Carolina's Office of State Fire Marshal guidance on rough plumbing and shower-pan inspections. Confirm every detail with the department that covers your address. Two neighboring cities can treat the same alcove differently.

Do you need a permit for a tub-to-shower conversion? The short answer

Usually yes when you replace the tub/shower enclosure or change the receptor, drain, or valve — not when you only swap a toilet or sink in the same location. Here is what the places we checked publish:

• Menifee, CA: "A permit is required for bathroom remodels that include the replacement of the tub/shower enclosure, relocation of plumbing fixtures or cabinets, or if additional plumbing fixtures will be installed." Sink or toilet replacement in the same location does not require a permit. (City of Menifee: Residential Bathroom Remodel Requirements)
• Pasadena, CA: a permit is required for bathroom remodels that include removal and replacement or relocation of vanity cabinets, toilets, sinks, tubs/showers, electrical work, or wallboard. Towel bars, mirrors, paint, and floor covers alone are maintenance and do not need a permit. (Pasadena Building & Safety: Residential Bathroom Remodel)
• Pleasanton, CA: a building permit is required for new, relocated, or remodeled bathrooms, and when replacing a bathtub or shower. Replacement of an existing bathtub with a shower compartment not exceeding 36 inches by 60 inches, with no plumbing or electrical changes beyond the fixture swap, can be processed with a permit application only (no plans). Larger layout changes go through plan review. (City of Pleasanton: Residential Bathroom Alteration Requirements)
• Sacramento, CA: if the project is limited to in-kind removal and replacement of electrical fixtures, plumbing fixtures, and/or wall or floor finishes, plans are not required and the job can issue as a Minor Bathroom Remodel Permit, subject to field verification. Creating or relocating openings in the bathroom's perimeter walls triggers full plan review. (City of Sacramento: Bathroom Remodels handout CDD-0418)
• San Bruno, CA: "A building permit is required when changing or installing a new shower stall, bathtub, or tub/shower combination." Inspection count depends on whether the pan is site-built and how the walls are waterproofed. (City of San Bruno: Shower and Tub Installations)
• Rancho Palos Verdes, CA: a permit is required for bathroom remodels and alterations; examples include replacing cabinetry, countertops, or fixtures in those areas. Shower pan tests must hold 2 inches of water for at least 24 hours. (City of Rancho Palos Verdes: Bathroom Remodel Requirements)
• Foster City, CA: bathroom remodel handouts list shower-size, waterproofing, 120°F valve, GFCI, and inspection requirements, including an optional shower-pan test when a new pan is installed and a required final after completion. (City of Foster City: Residential Bathroom Remodel)
• Austin, TX: residential plumbing exemptions cover clear stoppages, fixture repairs that do not rearrange valves or pipes, and similar limited work — but Austin adds an explicit override: "For purposes of Section 104.2, a new installation or replacement of a shower, tub, or combination tub and shower is not exempt from the permit requirements of this code." (Austin Development Services: Work Exempt from Building Permits)

So a like-for-like toilet swap may skate by, while a tub-to-shower conversion almost always crosses into permitted work. Austin removes any doubt for showers and tubs. California cities that publish bathroom remodel handouts treat enclosure replacement as a permit trigger even when the vanity stays.

What a tub-to-shower conversion actually changes

Photo: Federal Bureau of Investigation, Public domain, via Wikimedia Commons

A conversion is not a faucet swap. Typical scopes include:

• Removing the bathtub and surround
• Installing a prefabricated shower receptor or building a site-built pan with a waterproof liner
• Moving or resizing the drain (tubs and showers often use different drain locations and trap arrangements)
• Replacing the tub/shower valve with a pressure-balancing or thermostatic shower valve
• Building a curb or a curb-less (roll-in) threshold
• Waterproofing walls to the height the code handout requires, then tile or a listed surround
• Often adding or upgrading the exhaust fan, GFCI receptacle, or lighting near the wet area

That is why cities separate "replace the toilet where it sits" from "change the tub/shower enclosure." Menifee and Pasadena draw that line in plain language. Pleasanton still wants a permit for a bathtub-to-shower swap, but will skip plan review when the new shower stays within 36 by 60 inches and the rest of the plumbing and electrical layout does not change.

If you are adding a bathroom where none existed — new drain stack, new vent, new branch circuit — use our adding a new bathroom guide. A conversion inside an existing wet room is a different permit conversation, but the drain and vent rules still matter when you relocate the receptor.

Plumbing: drain location, valves, and the pan test

Plumbing is the part of a conversion that most often decides whether the inspector signs off.

Drain and trap

San Bruno lists a minimum 2-inch shower drain. Rancho Palos Verdes cites a minimum 2-inch drain and trap for showers. Pleasanton likewise requires a minimum 2-inch drain for shower compartments. If the old tub drain was smaller or in a different spot, expect rough plumbing work and a rough inspection before the pan is covered. Our gas and plumbing permit guide covers when moving supply lines triggers its own permit — shower conversions usually stay on the water and DWV side, not gas, unless you are also moving a nearby gas appliance.

Mixing valves and temperature limits

Menifee requires any new or replaced shower mixing valve (including over a tub) to be pressure-balancing and set to a maximum of 120°F; bathtub filler valves need a temperature-limiting device at the same 120°F maximum, and the water heater thermostat cannot be used to meet that rule (citing CPC 408.3 and 409.4). Pasadena, Pleasanton, Foster City, and Rancho Palos Verdes publish the same 120°F mixed-water limit for showers and tub/shower combinations. Sacramento requires pressure-balanced or thermostatic mixing valves for shower and tub-shower combination installations, noting they are required when the surround is removed or the valve is replaced.

Shower pan water test

Site-built pans are tested before they are covered. San Bruno describes filling a site-built receptor with water to the level of the rough threshold so both the upper and under sides of the sub-pan are tested, with lining pitched 1/4 inch per foot to weep holes. Pleasanton requires the shower pan liner under a 24-hour water test at the wet-wall / shower-pan inspection. Rancho Palos Verdes requires 2 inches of water sitting for at least 24 hours, with the plug below the weep holes so the membrane is tested. North Carolina's Office of State Fire Marshal publishes residential guidance on rough plumbing and shower-pan inspection sequencing for jurisdictions that use that framework (NCOSFM: Rough Plumbing and Shower Pan Inspection). Prefabricated receptors still need to be installed to the listing; cities may still want to see the drain connection and slope before tile.

Floor slope

San Bruno and Pleasanton both describe shower floor slope toward the drain — San Bruno at a minimum 1/4 inch per foot for drainage in its checklist notes; Pleasanton calls for slope in the 1/4 to 1/2 inch per foot range for the liner and lists final finished-floor slope toward the drain between 1/8 and 1/2 inch per foot. Foster City requires the finished floor of the shower pan receptor to slope uniformly from the sides toward the drain. Do not assume a flat mortar bed will pass.

Shower size, doors, and waterproof walls

Most California handouts we read repeat the same shower geometry:

• Minimum finished interior area: 1,024 square inches
• Clear circle: capable of encompassing a 30-inch diameter circle
• Door: swings out of the enclosure with a clear opening of at least 22 inches

Menifee, Sacramento, Pleasanton, San Bruno, and Rancho Palos Verdes all publish that 1,024 square inch / 30-inch circle pattern (Sacramento and Menifee cite CPC shower provisions). Sacramento adds an important exception for conversions: the minimum required area and dimensions "shall not apply where an existing bathtub is replaced by a shower receptor having overall dimensions of not less than 30-in in width and 60-in in length." That exception is for replacing a bathtub with a 30-by-60 receptor — not a free pass for a tiny neo-angle that fails the circle test when you are building a new shower stall from scratch. Confirm which path your city uses before you order the pan.

Wall finishes matter as much as floor area. Menifee requires shower stalls and bathtubs with shower heads to have a non-absorbent wall finish for a minimum of 6 feet above the floor. San Bruno requires smooth, hard, nonabsorbent surfaces to 72 inches above the drain inlet and notes that water-resistant gypsum ("green board") is no longer allowed in wet locations over a vapor retarder in shower or tub compartments. Sacramento likewise says greenboard is not an acceptable substrate; backing must be cementitious or gypsum board approved for the installation. Wet-area backer board is not ordinary living-room drywall; confirm approved substrates with your city before the surround comes out.

Tempered (safety) glazing shows up whenever glass sits near the tub or shower. Menifee and Pasadena require tempered glazing in walls enclosing the tub/shower when the bottom edge is less than 60 inches above the standing surface, and within 60 inches horizontally of the water's edge when the bottom edge is less than 60 inches above the walking surface. Sacramento uses a 5-foot vertical / horizontal pattern for safety glazing near bathtubs and spas. Order the right glass the first time; field tempering is not a weekend fix.

Electrical, exhaust, and lighting in the wet room

Conversions often pull electrical and mechanical work even when the homeowner only planned tile.

• GFCI receptacles: Menifee, Pasadena, Pleasanton, Sacramento, Foster City, and Rancho Palos Verdes all require GFCI protection for bathroom receptacles. Sacramento and Pasadena describe a 20-amp bathroom receptacle circuit; receptacles must not be installed inside the bathtub or shower space.
• Exhaust fans: Menifee requires a minimum 50 CFM exhaust fan even if an operable window exists, with separate switches for fan and light. Pleasanton and Sacramento publish 50 CFM intermittent (or 20 CFM continuous) outdoor-vented exhaust. Sacramento wants humidity control on the fan.
• Lighting near the shower: fixtures within about 3 feet horizontally and 8 feet vertically of the tub rim or shower threshold must be listed for damp locations, or wet locations if subject to shower spray (Menifee, Sacramento, Foster City). Cord-connected fixtures, track lights, pendants, and paddle fans are prohibited in that zone in Sacramento's handout.

If you are adding a new circuit or moving boxes, see our electrical permit guide for outlets and small jobs. Bathroom receptacle circuits are easy to get wrong when the old wiring shared a lighting circuit.

Inspections from rough-in to final

Photo: Stilfehler, CC BY-SA 4.0, via Wikimedia Commons

Cities stage bathroom inspections so waterproofing is not buried before it is checked. Patterns from the handouts:

• San Bruno: first inspection after framing and plumbing, before backer board or felt; site-built pans can be tested then. Second inspection after backer board, vapor barrier, and lath. Final after all work is complete.
• Pleasanton: rough inspection for framing, plumbing rough-ins, and (when scheduled) the liner under water test; wet-wall and shower-pan inspection with the 24-hour water test; final for fixtures, GFCI, slope, and alarms.
• Foster City: rough framing/plumbing/mechanical/electrical after framing and before concealment; optional shower-pan test for a new pan; required final after completion with smoke and carbon monoxide alarms addressed.
• Rancho Palos Verdes: inspections include drywall / interior lath / shower pan (waterproofing and pan), then finals covering GFCI tests and installed fixtures.

Schedule in the order your permit card lists. Covering a pan before the water test is one of the fastest ways to earn a correction notice. Our building permit inspection prep guide walks through how to show up ready and how to clear a correction list if something fails.

Accessibility, curb-less showers, and walk-in goals

Many conversions are motivated by safer entry: a low curb or a curb-less roll-in shower instead of a high tub wall. That goal does not remove the permit. A curb-less pan still needs waterproofing, slope to the drain, and the valve and glazing rules your city publishes. Door clear openings (22 inches minimum in the California handouts above) matter for everyday use; true accessibility clearances for wheelchairs are a different, stricter conversation — ask the building department about accessibility clearances when the bathroom work is part of a larger accessible path into the house. Tell the building department up front if you are building a curb-less receptor so plan review and the pan inspection know what to look for.

California water-fixture upgrades that ride with the permit

Several California cities remind homeowners that pulling a remodel permit can trigger whole-house water-fixture upgrades under California Civil Code 1101.4(a). Menifee and Pasadena publish tables: toilets above 1.6 gallons per flush must become 1.28 GPF (or the handout's listed rate); showerheads above 2.5 GPM must meet the listed low-flow rate; bathroom and kitchen faucets have their own caps. Homes built after January 1, 1994 are exempt from that Civil Code upgrade trigger in the Menifee and Pasadena handouts. Budget for those fixture swaps when you file — they are easy to miss until final.

Smoke and carbon monoxide alarms are another common final-inspection add-on when a bathroom remodel permit is open. Menifee recounts placement rules for smoke and CO alarms when permits are issued; Foster City and Pleasanton likewise expect alarms to be current at final. Pair this with our smoke and CO alarm remodel guide so you are not buying alarms the morning of the inspection.

HOA rules, contractors, and who pulls the permit

City approval is not HOA approval. Glass enclosures, tile colors, and construction hours can all need association sign-off even when the building department is ready. See HOA approval vs city building permit. Decide early who pulls the building permit — homeowner or contractor; many cities want the licensed plumber or general contractor on electrical and plumbing trades. If work already started without a permit, stop and read our after-the-fact permit guide before the pan is tiled over.

Tub-to-shower conversion: what usually needs a permit

Practical checklist before you demolish the tub

1. Call or message the building department with a one-sentence scope: "Replace existing bathtub with a shower receptor in the same alcove; drain may move; new mixing valve; tile surround." Ask whether plans are required.
2. Measure the alcove. If you need Sacramento's 30-by-60 conversion exception or Pleasanton's 36-by-60 no-plans path, confirm your pan fits before ordering.
3. Decide prefabricated receptor versus site-built pan. Site-built means a liner, slope, weep holes, and a water test on the inspection card.
4. Plan the valve: pressure-balancing or thermostatic, set to the city's maximum mixed temperature (120°F in the California handouts above).
5. Plan waterproofing height (commonly 6 feet / 72 inches above the floor or drain inlet in these handouts) and approved backer — not green board in shower compartments where the city bans it.
6. Check exhaust fan CFM, GFCI outlets, and damp/wet-listed lighting near the shower.
7. Ask whether Civil Code fixture upgrades or smoke/CO alarm updates will be checked at final.
8. Pull the permit before demolition. Austin's published rule is unambiguous for new or replacement showers and tubs; California remodel handouts treat enclosure replacement as permitted work.

If you are only swapping a toilet, faucet, or sink in the same spot, see our guide to permits for replacing plumbing fixtures.

FAQ

Do I need a permit to replace a bathtub with a shower?

In most places we checked, yes. Duluth, Minnesota, for example, says fixtures and finishes can be upgraded without a permit if everything is a like-for-like exchange, but if a shower is replacing the current tub, a building permit is needed (City of Duluth: Interior Remodels & Small Projects).

What other permits come with a tub-to-shower conversion?

Duluth lists a plumbing permit, an electrical permit, and an HVAC permit for the exhaust fan as what bathroom remodels usually need when a building permit is required. Other cities bundle these differently, so ask.

Can I keep my old tub drain for the new shower?

Only if it meets the size rule. The California handouts above call for a minimum 2-inch shower drain, so a smaller tub drain usually has to be upsized and inspected before the pan is covered.

Is there a minimum size for a shower that replaces a tub?

Many California handouts use 1,024 square inches with room for a 30-inch circle. Sacramento exempts a receptor of at least 30 by 60 inches that replaces an existing bathtub. Confirm your city's rule before ordering the pan.

Does a curbless walk-in shower still need a permit?

Yes. A curbless pan still needs waterproofing, slope to the drain, and the valve and glazing rules your city publishes.

Last checked: October 31, 2026.

Official sources

• City of Menifee — Residential Bathroom Remodel Requirements
• City of Pasadena — Residential Bathroom Remodel (2025)
• City of Pleasanton — Residential Bathroom Alteration Requirements
• City of Sacramento — Bathroom Remodels (CDD-0418)
• City of San Bruno — Shower and Tub Installations
• City of Rancho Palos Verdes — Bathroom Remodel Requirements
• City of Foster City — Residential Bathroom Remodel
• Austin Development Services — Work Exempt from Building Permits (includes the shower/tub non-exemption note)
• North Carolina Office of State Fire Marshal — Rough Plumbing and Shower Pan Inspection
• City of Duluth, MN — Interior Remodels & Small Projects (tub-to-shower permit note)

Edited by Ahmed Khalifa, founder of PermitCove. Sources are linked inline; see our Editorial Policy.