Do I need a permit for a full bathroom remodel in
Des Moines, Washington?

Des Moines full bathroom remodel permits — the key details

The core rule: Des Moines Building Department requires a permit for any bathroom work that changes the footprint, adds new circuits, or alters the water supply or drain route. This is driven by IRC P2706 (drainage fittings — traps and vent stacks must be sized and routed per code) and IRC M1505 (exhaust fan ductwork must terminate outside and be sized to the room cubic footage). What trips up homeowners most is the assumption that 'just replacing the toilet and sink' needs a permit — it doesn't, as long as they stay in their original locations and you're not touching the supply lines or drain. The moment you move a fixture even 3 feet, or add a second exhaust fan, or relocate the toilet to a different corner of the room, you cross into permit territory. The city's building official will ask: does this work require a new vent stack? Does it change the slope of the drain? Does it add new electrical loads? If yes to any, permit required.

Electrical work in bathrooms triggers strict GFCI (ground-fault circuit interrupter) and AFCI (arc-fault circuit interrupter) requirements under NEC 210.12 and 680.71. Any outlet within 6 feet of the sink or tub must be GFCI-protected; any new 120-volt circuit feeding bathroom outlets must be AFCI-protected at the breaker. Des Moines inspectors expect to see these protection methods clearly labeled on your electrical plan before rough-in inspection. Many DIYers wire new outlets without realizing they've added a circuit that now requires AFCI protection on the breaker — the plan reviewer will catch it and ask for a correction. If you're adding a heated floor mat or a new ventilation fan with a dedicated circuit, those details go on the electrical drawings you submit with your permit application. There's no exception for owner-builders here; the code is the code. The city has one online checklist for bathroom electrical work, which you can download from the permit portal, that lists exactly what the inspector is looking for.

Plumbing fixture relocation is the most common permit trigger. If you're moving the toilet, sink, or tub, the rough-in inspection happens before drywall goes up — the inspector verifies that vent stacks are properly sized (IRC P3103), that trap arms don't exceed 42 inches horizontal run without a vent (IRC P3105), and that the drain slope is between 1/4 inch and 1/2 inch per foot (IRC P2704). Des Moines is in Puget Sound west and glacial-till soil east, so foundation settling and frost heave (12 inches frost depth west of the sound, 30+ inches east) can stress plumbing lines over time; code-compliant installation with proper support clamps and vent paths reduces that risk. If you're moving a toilet 5 feet but the new location is farther from the stack, you might need to install a separate vent or modify the existing vent path — this is where a plumber's pre-design consultation saves you from a plan rejection. The city's plan review process usually flags vent issues early, and you have the option to revise and resubmit at no additional fee.

Shower waterproofing is a critical documentation point in Des Moines' wet climate. IRC R702.4.2 mandates a waterproofing assembly behind any installed shower enclosure or tub surround; the code lists several acceptable methods (cement board plus membrane, gypsum board plus membrane, or ANSI/IAPMO tested water-resistant systems). Your permit application must specify which method you'll use — saying 'waterproofed drywall' is not specific enough and will be rejected. Inspectors will ask to see your chosen product (the membrane brand, the cement-board spec sheet) before drywall closes over it. Puget Sound humidity means mold risk is real if the waterproofing is substandard, so the city doesn't skip this step. Many homeowners expect to handle this during tile installation, but the waterproofing must be inspected before tile goes on; you'll schedule a rough-framing or drywall inspection that includes the waterproofing check. If you're converting a tub to a walk-in shower, the footprint and drain location change, so you'll definitely trigger a permit, and the waterproofing assembly becomes a line-item on the plan.

Timelines and inspections typically span 3–4 weeks from permit issue to final sign-off. After you pull the permit online (or at city hall), plan review takes 2–3 weeks; the reviewer may ask for clarifications (usually via email through the portal) or approve with no comments. Once approved, you schedule rough plumbing inspection (before drywall), rough electrical inspection (after outlets and circuits are roughed in but before cover plates), and final inspection (after trim, fixtures, and flooring are complete). Some remodels skip the framing inspection if no walls are moved; Des Moines allows this if the scope is truly fixture-relocation-only. Owner-builders can schedule inspections online or by phone; the city typically has a 2–3 day window for inspector availability. If an inspection fails (most common: vent not properly sized, GFCI outlet in wrong location, waterproofing not up to spec), you get a written correction notice and a re-inspection window — no additional permit fee, but 3–5 more days added to your timeline. Plan accordingly if you're on a tight schedule; many contractors build in a 5-week buffer for a full remodel.

Three Des Moines bathroom remodel (full) scenarios

Waterproofing assemblies in Des Moines' Puget Sound humidity environment

Des Moines sits in one of the wettest climates in Washington state; annual precipitation exceeds 35 inches, and humidity is persistent even in summer. This is why IRC R702.4.2 waterproofing is non-negotiable and inspectors are strict about enforcement. If you're tiling a shower wall or installing a new tub surround, the waterproofing membrane must be behind the tile, not under it. Cement board (not standard drywall) is the standard substrate, and the membrane is typically a liquid-applied or sheet-applied product meeting ASTM D1970 or equivalent. Some homeowners try to save money by skipping the membrane and relying on 'waterproofed drywall' or grout alone — this fails in Puget Sound conditions within 3–5 years, as moisture wicks behind the tile and causes mold, wood rot, and structural damage.

The city's building inspector will ask to see the waterproofing product before drywall is closed. You should have the membrane product in hand (brand, model, ASTM rating) when you submit your permit plan, or note 'cement board + liquid membrane per ASTM D1970 (brand TBD)' and provide it during framing inspection. If you're using a pre-fabricated shower system (solid composite surround), the manufacturer's waterproofing guarantee often exceeds code minimum, and you'll submit their spec sheet instead. Tile setters commonly assume grout is waterproof — it's not; grout is porous and moisture-permeable. The membrane behind the tile is the actual waterproof layer. If you hire a tile contractor, specify in the contract that you want cement board (not drywall) and a full waterproofing membrane; get their material list in writing before work starts so the plan reviewer and inspector can verify it matches your permit application.

Cost impact: a proper waterproofing assembly (cement board + membrane) adds $150–$400 to a single-wall shower enclosure, compared to standard drywall and grout. It's worth every cent in Des Moines; skipping it risks a rejected inspection and future water damage that's far more expensive. Some homeowners in dry climates can cut corners with grout-only finishes; don't try it here.

Permit portal workflow and online plan submission in Des Moines

Des Moines Building Department operates an online permit portal where you can submit plans, pay fees, check status, and schedule inspections — all without visiting city hall in person. This is a significant advantage over jurisdictions like Shoreline or Edmonds, where you still need to hand-deliver plans and wait in line. To start, you'll create an account on the city's portal, provide your property address and project description, and upload PDF plans. For a full bathroom remodel, the city asks for a site plan (showing the property and bathroom location), floor plan (before and after fixture layout), electrical plan (if adding circuits or outlets), plumbing plan (if relocating fixtures), and a materials list. Owner-builders can submit these themselves; GCs typically handle it. The portal will calculate your permit fee based on estimated cost of work (you enter a rough dollar amount; the city's fee schedule is 1% of estimated work cost, capped at $800 for residential projects).

Plan review happens within 2–3 weeks. The reviewer comments via the portal (usually email), asking for clarifications like 'specify vent stack size' or 'show GFCI outlet location.' You revise the PDFs and re-upload; no re-submission fee. Once approved, you get an email with your permit number and inspection scheduling instructions. You can book inspections online for most slots, or call the building department if you need a specific time. The portal displays your inspection history, so you can see what failed or passed and plan next steps. If you fail an inspection, the inspector uploads a report to the portal detailing required corrections; you make fixes and request a re-inspection, again at no additional fee. This digital workflow is much faster than older jurisdictions that mail inspection reports and require phone calls to re-schedule.

Tip: before uploading plans, download the city's 'Bathroom Permit Checklist' (usually available on the portal) and use it as a guide for what to include. Common omissions that delay review: no vent stack size labeled, no waterproofing product specified, no GFCI outlet marked on electrical plan, and no exhaust fan CFM rating. Having these details in your initial submission cuts review time by a week.

Common questions