Do I need a permit for a full bathroom remodel in
San Dimas, CA?

San Dimas full bathroom remodel permits — the key details

San Dimas Building Department requires a permit for any bathroom remodel that includes fixture relocation, new electrical circuits, exhaust fan installation, tub-to-shower conversion, or wall removal. The baseline code is the California Building Code (Title 24), which incorporates the International Building Code with California amendments. For plumbing, the city enforces the California Plumbing Code (IPC with amendments); for electrical, Title 24 Part 3 (the California Electrical Code, which is the NEC with amendments). For a 'full remodel' (which typically means gutting the bathroom and rebuilding), you will almost certainly trigger the permit threshold. The California Building Standards Commission updates the Code every three years; San Dimas adopted the 2022 California Building Code effective January 1, 2023, so any plans submitted after that date must comply with 2022 standards. Waterproofing requirements are strict: IRC R702.4.2 (adopted in California) mandates that any shower or bathtub enclosure have a water-resistive barrier (cement board or gypsum board with a secondary membrane). The city's plan checker will require you to specify the membrane type — KERDI, RedGard, sheet-membrane rubber, or equivalent — and to show installation details in cross-section on the plan. Many homeowners underestimate this and submit plans that just say 'membrane per code,' which gets a rejection comment.

Electrical permits are non-negotiable. Any bathroom remodel that adds a new circuit, relocates an outlet, or installs new lighting must be permitted under Title 24 Part 3. The city requires GFCI protection on all receptacles within 6 feet of a sink, tub, or shower (per NEC Article 210.8, adopted in California). If you're roughing in a new exhaust fan, the circuit must be on a dedicated breaker and the switch must be within 6 feet of the fan (not in an adjoining bedroom). Many contractors miss the requirement for a timer or humidity-sensor switch, which Title 24 requires in new installations to reduce over-ventilation. San Dimas plan-check sheets specifically call out 'GFCI/AFCI layout must be clearly marked on electrical plans'; if it's not shown, you'll get a comment loop. Licensed electricians only — you cannot, as an owner-builder, pull an electrical permit for your own labor in California. The licensed electrician on the job must sign the permit and be responsible for all rough and final inspections. This is a California state rule, not a San Dimas local rule, but it's strictly enforced at the municipal level.

Plumbing fixture relocation is the second major trigger. Any bathroom remodel that moves a toilet, sink, or tub to a new location requires a permit. The drain-waste-vent (DWV) system must be redesigned and shown on plans. The most common code violation here is trap-arm length: the distance from the trap to the vent stack cannot exceed certain limits (typically 5 feet for a 1.5-inch arm), and the slope must be 1/4 inch per foot downhill toward the drain. San Dimas plan checkers flag trap-arm violations frequently because older homes have tight layouts and contractors try to re-use existing vent stacks that don't suit the new fixture position. Additionally, any new or modified trap requires a cleanout, and the location must be accessible (not hidden behind a wall). If you're converting a tub to a shower (or vice versa), this is treated as a plumbing relocation and also a waterproofing-assembly change; you'll need both plumbing and 'building' (structural/waterproofing) permits. The city issues these as separate permit types but on a single application. You must provide a licensed plumber; the plumber signs the permit, pulls the rough-plumbing inspection, and signs off the final. California law does allow owner-builder permits, but the plumbing contractor is liable for code compliance.

Ventilation (exhaust fans) is often overlooked but code-critical. Any new or relocated exhaust fan must be ducted to the exterior (not to an attic or soffit, per IRC M1505). The duct size must match the CFM rating: a typical bathroom needs 50 CFM for a small space or 80 CFM for larger rooms. The duct run should not exceed 25 feet in equivalent length (straight runs count as 1 foot, each 90-degree elbow adds 10 feet). The termination must be a dampered vent hood on an exterior wall or roof, not a louvered vent (which allows backflow). San Dimas plan-check sheets require a detail showing the duct termination and the damper type. If the plan doesn't show this, you'll get a comment. Also, if the bathroom is on an upper floor and the duct runs through the attic, you must show insulation around the duct to prevent condensation dripping into attic insulation (a fire and mold risk). This detail is often missed by DIY plan submitters.

The permit application process in San Dimas is hybrid: you can submit online via the city's permitting portal or in person at City Hall. The portal (accessible from the City of San Dimas website) accepts PDF plans, applications, and documents. Plan review typically takes 7–10 business days for a standard bathroom remodel; complex layouts or waterproofing questions can add another 5–7 days. Once the permit issues, you have two years to complete the work (renewable if you file before expiration). Rough plumbing inspection comes first, then rough electrical, then framing (if drywall is being altered), then drywall/waterproofing inspection (for the shower assembly), and finally final plumbing, electrical, and building final. If you're only replacing fixtures in place, you skip most of these; a final inspection of the sink and toilet suffices. Permit fees for a full bathroom remodel typically range from $350 to $800, depending on the estimated project cost (valuation). San Dimas applies a fee of roughly 1.5–2.0% of the permit valuation, with a minimum plan-check fee of around $100–$150. Adding electrical circuits incurs a surcharge (typically $50–$100 per circuit); plumbing fixture relocation adds another $100–$200. Get a pre-application meeting with the plan checker if you're unsure — it's free and can prevent a full rejection loop.

Three San Dimas bathroom remodel (full) scenarios