Bathroom Remodel Permit in Lomita, CA (2026)

Research by DoINeedAPermit Research Team · Updated May 2026

The Short Answer

A full bathroom remodel in Lomita requires a permit whenever you relocate plumbing fixtures, add electrical circuits, install new exhaust ventilation, convert a tub to shower, or move walls. Cosmetic-only updates (tile, vanity replacement in place, faucet swap) do not need permits.

Lomita, located in San Mateo County on the Peninsula, enforces California Title 24 standards and the 2022 California Building Code with specific coastal amendments for moisture and salt-air durability. Unlike some Bay Area neighbors (Burlingame, San Mateo proper), Lomita's Building Department does not offer a separate 'standard vs. complex' plan-review track — all bathroom remodels with fixture relocation or new circuits route through full plan review, not over-the-counter approval. This means your timeline is typically 3–5 weeks, not same-day. Lomita also requires an early consultation with the Building Department if your home was built pre-1978 (lead-paint inspection) or sits in a seismic retrofit overlay (common in Lomita's hillside zones) — these add 1–2 weeks. The permit fee structure is based on valuation: expect $250–$600 for a mid-range remodel ($15,000–$30,000), plus plan-review fees if the design is flagged for shower waterproofing detail or GFCI/AFCI circuit specificity. Lomita's coastal climate (salt fog, high humidity) means your shower waterproofing assembly (cement board + membrane type, or equivalents) must be explicitly detailed and approved — not just 'per code.'

What happens if you skip the permit (and you needed one)

Stop-work orders in Lomita carry fines up to $250 per day plus you'll be required to pull a permit retroactively and pay double the original permit fee — a $400 permit becomes $800 plus 30+ days of re-review.
Insurance denial: your homeowner's policy will not cover unpermitted bathroom work, and many insurers will deny claims if water damage occurs post-remodel (a $15,000–$40,000 claim can vanish).
Resale disclosure: California law (CLUE/TDS) requires you to disclose unpermitted work to buyers; non-disclosure can result in fines up to $5,000 and rescission rights for the buyer.
Refinance or home-equity blocking: lenders will not fund against unpermitted alterations; if discovered during appraisal, you'll need to permit-and-inspect retroactively (costly and time-consuming in Lomita).

Lomita full bathroom remodels — the key details

Lomita requires a building permit whenever any plumbing fixture (toilet, sink, tub, or shower) is relocated, any electrical circuit is added (especially GFCI/AFCI circuits for bathrooms per NEC 210.12), a new exhaust fan or duct is installed, a tub is converted to a shower (or vice versa) — this triggers waterproofing assembly review per IRC R702.4.2 — or any walls are moved. Fixture replacements in the exact same location (same supply lines, same drain) do not require permits; you can swap out a toilet, faucet, or vanity without notifying the city. However, the moment you shift the toilet 2 feet to the left or install an exhaust fan where none existed, you cross into permit territory. Per the California Building Code (adopted by Lomita with no significant local amendments), the Plumbing Code (Title 24, Part 5) governs drain sizing, vent sizing, and trap-arm length — a common rejection point when homeowners or unlicensed contractors specify traps that are too far from the vent stack.

Waterproofing is the single largest cause of plan-review rejections in Lomita bathroom remodels, especially for shower conversions. IRC R702.4.2 requires a 'water-resistive barrier' behind all shower and tub surrounds; the code does not mandate cement board, but Lomita's plan reviewers expect explicit specification: 'Schluter KERDI membrane on drywall' or 'cement board + 6-mil polyethylene + tile' or 'liquid-applied membrane (RedGard, Hydro Ban, etc.) per manufacturer spec.' If you submit plans that say 'waterproof drywall' without a membrane layer, expect a request for information (RFI) — a 7–10 day delay. Exhaust ventilation must be documented too: IRC M1505 requires a minimum 50 CFM continuous or 100 CFM intermittent; the duct must terminate outside (not into an attic), and the duct diameter must match the fan outlet (typically 4 inches for residential). Lomita's coastal humidity means inspectors often verify the exterior termination cap is marine-grade and has a hood to prevent backdrafting.

Electrical work in bathrooms triggers GFCI and AFCI requirements that must be explicitly shown on your electrical plan. NEC 210.8 (adopted by California) mandates GFCI protection for all 120-volt, single-phase, 15- and 20-ampere receptacles in bathrooms, kitchens, garages, and other wet locations. If you're adding a dedicated circuit for a heated towel rack, a new light, or a ventilation fan, your electrical plan must call out GFCI breakers or outlets and label them on the diagram. AFCI (arc-fault circuit interrupter) protection is required for all branch circuits that supply outlets in bathrooms per NEC 210.12. Many DIY plans omit this detail, triggering an RFI. Plumbing fixture shutoffs are another common miss: if you relocate the toilet or sink, you must provide individual shutoff valves accessible within 12 inches of the fixture — code inspectors will fail rough plumbing if the valves are buried or inaccessible.

Lead-paint compliance is mandatory for pre-1978 homes in Lomita. The EPA Renovation, Repair, and Painting Rule (RRP) requires that if your bathroom remodel disturbs more than 6 square feet of painted surfaces, you must use a lead-safe work practice (containment, HEPA vacuum, wet wipe-down). Your permit application will ask the year of construction; if pre-1978, you must include an RRP notification or evidence of lead-safe certification for your contractor. Skipping this adds $500–$1,000 in fines and can halt your project mid-inspection. Seismic retrofit overlays affect some Lomita properties (especially in the hills); if your home is in a retrofit zone, the Building Department may require additional bracing or anchoring review, adding 1–2 weeks to plan review. You'll know this from your property report — ask the Building Department or your title company upfront.

The typical inspection sequence for a Lomita bathroom remodel is: (1) Plan check (3–5 weeks); (2) Rough plumbing (city verifies vent stacks, trap arms, fixture locations); (3) Rough electrical (GFCI/AFCI circuits, outlet locations); (4) Framing/waterproofing (if walls move or shower enclosure is new — inspector checks membrane continuity before tile); (5) Final (all fixtures installed, exhaust fan duct terminated, all code signoffs). If you're not moving walls and only replacing fixtures, framing inspection may be waived. Bring your permit and proof of contractor licensing (if using licensed plumber/electrician) to each inspection — Lomita inspectors will not sign off if you're using unlicensed subs for plumbing or electrical. Owner-builders are allowed under California Business & Professions Code § 7044, but plumbing and electrical work must be performed by a licensed contractor (Lomita interprets this strictly). Total timeline from permit pull to final sign-off is typically 6–8 weeks; plan for 3–5 weeks plan review plus 1–2 weeks for inspections and minor corrections.

Three Lomita bathroom remodel (full) scenarios

Scenario A

Cosmetic bathroom update — new tile, vanity swap, faucet replacement in place, existing exhaust fan remains, Hillside bungalow

You're replacing the old tile, pulling out the existing vanity, and installing a new one in the same footprint (same supply and drain lines), plus a new faucet on the same hot/cold stubs. The exhaust fan stays in place and works fine. This is surface-only cosmetic work and does not require a permit from Lomita. You do not file anything, pay no permit fees, and do not schedule inspections. However, if your home was built before 1978, you must follow EPA RRP lead-safe practices while removing old tile and paint — get a lead test done first or hire an RRP-certified contractor ($400–$800). Even without a permit, if your remodel is sloppy (water damage from poor tile sealing, for instance), your homeowner's insurance may not cover it because 'unpermitted bathroom work' is often cited as grounds for denial. To be safe, document your work with photos and receipts; if you ever sell, you can honestly state the work was cosmetic and not unpermitted. Keep the receipts and before-after photos in a file. Total cost for materials and labor: $4,000–$8,000 (tile, vanity, faucet, grout, simple labor). No permit cost.

No permit required (cosmetic only) | Lead-safe RRP compliance required if pre-1978 | Supply/drain lines unchanged | Total project $4,000–$8,000 | No permit fees

Scenario B

Toilet + sink relocation, new exhaust fan duct, coastal hillside home with seismic retrofit overlay

You're moving the toilet from the far corner to the wall adjacent to the tub (2–3 feet away), relocating the sink to the opposite wall, and installing a new exhaust fan with a 4-inch duct that terminates through the roof. This involves new plumbing runs, new electrical (duct fan power), and new ductwork routing. Permit required. You'll file with Lomita Building Department (allow 1–2 days for intake), pay a building permit fee of $300–$500 based on valuation (assume $18,000 remodel), plus plan-review fees ($100–$150). Because your home is in a seismic retrofit overlay (common in Lomita's hillside zones), the plan reviewer will check that any wall anchoring or bracing is maintained if you're opening the wall for new plumbing. Plan review takes 4–6 weeks (the overlay adds 1 week). You'll need licensed plumber and electrician; owner-builder is not allowed for plumbing or electrical. Rough plumbing inspection: city verifies the new toilet drain is less than 6 feet from the vent stack (IRC P3005.1 — trap-arm length limit), the sink drain ties in properly, and shutoff valves are accessible. Rough electrical: inspector confirms the duct fan is on a dedicated GFCI circuit. Waterproofing is not a focus here since fixtures are not moving into a new location that changes moisture exposure. Exhaust duct: inspector verifies duct is 4 inches, slopes slightly toward the bathroom, and terminates at the roofline with a marine-grade hood (Lomita coastal requirement — prevent salt-fog backdraft). Final inspection after all trim, fixtures, and duct termination are complete. Timeline: 3–5 weeks plan review, 2–3 weeks for inspections and corrections, 6–8 weeks total. Seismic overlay review may delay approval by 1 week. Total project cost: $12,000–$20,000 (plumbing, electrical, ductwork, finish). Permit and review fees: $400–$650.

Scenario C

Walk-in shower conversion (tub to shower), waterproofing system specified, new framing in wet wall, pre-1978 Peninsula home

You're removing the existing tub, framing and waterproofing a new 5-foot walk-in shower in its place, and moving the existing shower valve to a new location on the wet wall. This is a full scope: fixture relocation (shower valve), new framing in a wet zone, and a waterproofing assembly that must be approved per IRC R702.4.2. Permit required; this is a flagged project because waterproofing assembly is the #1 rejection reason in Lomita. Before you file, contact the Lomita Building Department and ask for the 'bathroom waterproofing detail sheet' or equivalent — they may have a preferred assembly. Typical approved systems in Lomita: (1) cement board on studs, 6-mil polyethylene membrane, tile and mortar; (2) Schluter KERDI (or equivalent liquid-applied membrane like Hydro Ban) on drywall, tile and thin-set; (3) preformed shower pan (Pan King, USG, etc.) with waterproofing membrane above. Your plans must show the assembly in section view — not just 'per code.' File the permit ($350–$600 based on $22,000 valuation), and expect 4–6 weeks plan review because the waterproofing detail will be reviewed by a senior inspector or third-party reviewer. Your plan will be marked 'Requests for Information (RFI)' asking you to clarify the exact membrane brand, thickness, coverage, and sealing details at corners and penetrations. Respond within 7 days with photos, spec sheets, and revised plans. Lead-paint compliance: your pre-1978 home requires RRP lead-safe work practices and a lead inspection before tile removal — budget $800–$1,200 for lead testing and RRP contractor oversight. Plumbing and electrical must be licensed. Inspections: rough framing (city checks waterproofing substrate before drywall or cement board is installed), rough plumbing (shower valve location and supply/drain), rough electrical (light and exhaust fan circuits), waterproofing/pre-tile (inspector visually verifies membrane installation), final tile/trim/fixtures. Total timeline: 4–6 weeks plan review, 3–4 weeks on-site inspections and corrections, 8–10 weeks total. Total project cost: $18,000–$28,000 (framing, waterproofing, plumbing, electrical, tile, fixtures). Permit and fees: $450–$750.

Permit required (tub-to-shower conversion + waterproofing assembly) | Waterproofing detail must be pre-approved (4–6 week plan review) | Pre-1978 lead-safe RRP compliance mandatory | Licensed plumber/electrician required | Framing and waterproofing inspections critical | Total project $18,000–$28,000 | Permit fees $450–$750

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Waterproofing assembly: the Lomita coastal requirement and plan-review trap

A second coastal consideration is exhaust-fan duct termination and marine-grade hood. Lomita's salt fog (especially in lower elevations near Highway 101) corrodes standard aluminum duct hoods within 5–7 years. Inspectors often require or recommend a stainless-steel or vinyl-coated hood, which costs an extra $60–$120 but prevents rust staining and operational failure. The duct itself should be insulated (not bare metal) to prevent condensation drip-back into the bathroom during humid nights. If you're routing the duct through a vented soffit or gable end, the inspector will verify the termination is sealed with silicone caulk and the hood is angled downward to shed water. Many DIY installers route the duct into the attic (a code violation) thinking it's 'ventilated.' Lomita inspectors catch this 100% of the time and require immediate correction — the duct must exit the building envelope. Budget an extra $200–$400 if your duct routing is complex (long run, multiple bends, marine-grade hood).

Plumbing fixture relocation: trap-arm length, venting, and the pre-1978 lead issue

Lead paint compliance for pre-1978 Lomita homes is a separate but critical path. The EPA Renovation, Repair, and Painting Rule (RRP) applies to any renovation disturbing more than 6 square feet of painted surfaces in a home built before 1978. Most full bathroom remodels disturb far more than 6 square feet (walls, trim, old tile adhesive on substrate, window frames, door jambs). You must: (1) get a lead inspection by an EPA-certified inspector ($300–$500); (2) use a lead-safe work practice (containment with plastic sheeting, HEPA vacuum, wet wipe-down, no sanding); (3) hire a lead-safe certified contractor or follow RRP rules yourself (if owner-builder). Many Lomita properties (especially the older Peninsula homes from the 1950s–1960s) are pre-1978. If your permit application lists your home as pre-1978 and you don't disclose RRP compliance on the plan, the Building Department may halt your permit approval pending RRP documentation. The cost of RRP compliance is $1,000–$2,000 (lead inspection + certified contractor oversight), but it's mandatory and non-negotiable. Factor this into your budget upfront.

City of Lomita Building Department
Lomita City Hall, Lomita, CA (verify exact address locally)
Phone: Contact Lomita City Hall main line and ask for Building Department | https://www.google.com/search?q=lomita+CA+building+permit+portal
Monday–Friday 8:00 AM–5:00 PM (verify locally)

Common questions

Do I need a permit to replace my bathroom faucet and toilet in Lomita?

No permit is needed if you're replacing the faucet and toilet in their existing locations using the existing supply and drain lines. This is considered a fixture swap and is exempt. However, if you're moving the toilet to a new location or rerouting the supplies, you'll need a permit. If your home was built before 1978, you must follow EPA lead-safe practices when removing the old toilet and faucet (which may involve lead-painted fasteners or caulk).

How much does a bathroom remodel permit cost in Lomita?

Permit fees for a full bathroom remodel in Lomita range from $250 to $600, depending on the valuation of the work. Plan-review fees (if required) add an additional $100–$200. A $15,000 remodel typically costs $300–$450 in permit fees; a $25,000 remodel costs $400–$600. Fees are non-refundable even if you halt the project. Contact the Building Department for an exact quote based on your scope.

What's the biggest reason bathroom remodel plans are rejected in Lomita?

Waterproofing assembly detail. Most rejections happen because plans don't specify the exact waterproofing system (brand, thickness, sealing method). Lomita's coastal climate requires explicit documentation: 'Schluter KERDI membrane,' 'cement board + 6-mil polyethylene,' or 'liquid-applied RedGard.' If your plan just says 'waterproofed per code,' expect a request for more information. Contact the Building Department before filing to ask which systems they've approved.

Do I need a licensed plumber and electrician for my Lomita bathroom remodel?

Yes. California law (B&P Code § 7044) allows owner-builders to perform certain work, but plumbing and electrical work in bathrooms must be performed by a licensed contractor. You cannot pull a permit for plumbing or electrical as an owner-builder. Verify contractor licenses at the California Contractors State License Board website before hiring.

How long does plan review take for a Lomita bathroom remodel?

Standard plan review takes 3–5 weeks. If your home is in a seismic retrofit overlay (check with the Building Department) or if waterproofing details are incomplete, add 1–2 weeks. Once approved, on-site inspections (rough plumbing, rough electrical, waterproofing, final) take 2–4 weeks depending on how quickly you schedule them. Total timeline is typically 6–8 weeks from permit pull to final sign-off.

What if my home was built before 1978? Does that affect my bathroom remodel permit?

Yes. Pre-1978 homes likely contain lead paint. You must follow EPA RRP lead-safe work practices (containment, HEPA vacuum, wet wipe-down) if your remodel disturbs more than 6 square feet of painted surfaces — which most bathroom remodels do. Get a lead inspection ($300–$500) before starting, and hire an RRP-certified contractor or follow RRP rules yourself. Cost: $800–$1,500 for compliance. Your permit application will ask for proof of RRP compliance.

Can I move a toilet to a new wall in my Lomita bathroom without a permit?

No. Moving a toilet requires a new plumbing drain run, which requires a permit. The city must verify the new trap-arm length (distance from toilet trap to vent stack) does not exceed 6 feet per IRC P3005.1, and that supply and shutoff valves are properly installed. Expect 6–8 weeks total (plan review + inspections). Budget $250–$600 in permit fees plus $3,000–$6,000 in plumbing labor and materials.

Do I need a permit for a new exhaust fan in my Lomita bathroom?

Yes. A new exhaust fan requires an electrical permit (new GFCI circuit) and potentially a mechanical permit (duct and termination). The duct must terminate outside the building envelope with a marine-grade hood (important for Lomita's salt fog). Plan review is typically 3–4 weeks. Permit fees: $200–$400. Budget $800–$1,500 for labor and marine-grade hood installation.

What happens if I remodel my bathroom without a permit in Lomita?

You risk stop-work orders (fines up to $250/day), double permit fees if caught and required to pull retroactively, insurance denial for water damage, and disclosure requirements at resale (California law). Lenders may also refuse to refinance if unpermitted work is discovered. A $400 permit now costs you $800 plus 30+ days of re-review if you skip it. Not worth the risk.

Is there a way to speed up Lomita's plan review for my bathroom remodel?

Plan review timelines are standard (3–5 weeks). You can speed up approval by submitting a complete plan set the first time: detailed waterproofing assembly, GFCI/AFCI electrical diagram, licensed plumber/electrician names, and lead-safe RRP documentation (if pre-1978). Incomplete submissions trigger RFIs and delay approval by 7–10 days. Contact the Building Department before filing to confirm all required documents and get approval on waterproofing details upfront.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current bathroom remodel (full) permit requirements with the City of Lomita Building Department before starting your project.

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