Bathroom Remodel Permit in Johnston, IA (2026)

Research by DoINeedAPermit Research Team · Updated May 2026

The Short Answer

A full bathroom remodel in Johnston requires a permit if you're relocating plumbing fixtures, adding electrical circuits, installing a new exhaust fan, converting tub to shower, or moving walls. Surface-only work — swapping a vanity or faucet in place — does not need a permit.

Johnston's Building Department enforces Iowa Building Code (which adopts the International Residential Code with state amendments), and the city processes permits through an over-the-counter review for straightforward scopes or full plan review for complex work. Unlike some surrounding communities, Johnston does not have a separate expedited 'minor remodel' category — a bathroom with any fixture relocation goes through the same intake process as any structural or systems change. The city also requires that all electrical work in bathrooms be shown on a licensed electrician's plan (or owner-builder documentation if you're the homeowner), including GFCI and AFCI protection per IRC E3902. If your project involves only cosmetic swaps — new tile, vanity replacement in the same footprint, faucet upgrade — Johnston will not require a permit, but you'll need to document that fixtures are not moving and no electrical circuits are being added. Lead-based paint rules apply to homes built before 1978, which affects dust control and disclosure.

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

Stop-work orders and fines: Johnston Building Department can issue a stop-work notice and fine you $100–$500 per violation, plus you'll be ordered to remove unpermitted work or bring it into compliance.
Insurance and liability: Many homeowners' insurers will deny claims related to unpermitted work, leaving you liable for injury, water damage, or electrical fire — a $50,000+ exposure for a bathroom flood.
Lender and refinance blocking: If you pull a construction loan or refinance, the lender's appraisal and title search will flag unpermitted work; the bank may demand removal or price concessions, costing $10,000–$40,000.
Resale disclosure and price hit: Iowa Real Estate Commission requires disclosure of unpermitted work on the transfer statement; buyers will demand $15,000–$50,000 in price reductions or proof of retroactive permitting.

Johnston bathroom remodel permits — the key details

Johnston requires a permit anytime you move a plumbing fixture, add or modify electrical circuits, install a new exhaust fan with ductwork, convert a bathtub to a shower (or vice versa), or relocate any walls. This is governed by Iowa Building Code Section 330.2 (adoptive reference to IRC), and Johnston's Building Department enforces IRC P2706 for drainage fittings, IRC M1505 for exhaust ventilation, IRC E3902 for GFCI/AFCI protection, and IRC R702.4.2 for shower and tub waterproofing assemblies. If your scope includes moving the toilet, sink, or tub even a few feet, or if you're adding a vent fan where none exists, a permit is required. The distinction is critical: replacing the toilet in place with a new model, swapping a faucet handle, or retiling an existing shower wall are cosmetic changes and do not trigger a permit. But if you're moving the toilet to a new wall or converting a tub alcove to a walk-in shower with a threshold, you'll file a full bathroom remodel permit.

Electrical work in Iowa bathrooms is strictly regulated. IRC E3902 requires GFCI protection for all outlets within 6 feet of a sink, bathtub, or shower; it also mandates AFCI (arc-fault circuit interrupter) protection on all branch circuits that serve the bathroom. If you are not a licensed electrician, you must hire one to design and stamp the electrical plan, or if you qualify as an owner-builder (homeowner working on your own occupied dwelling), you can do the work yourself but must show the plan to the Building Department and pass rough and final inspections. Johnston's Building Department requires that electrical plans for bathroom work specify the circuit type, protection devices, wire gauge, and junction box locations. Many homeowners and contractors fail to detail this upfront, causing plan rejections and 2–3 week delays. Hire the electrician early — during design — not after you've already framed, or you'll face rework costs.

Plumbing and drainage rules are equally strict. If you're relocating a drain line (toilet, sink, or tub), IRC P2706 limits the trap arm (the horizontal pipe between the fixture outlet and the vent stack) to 42 inches; if your bathroom layout forces a longer run, you'll need a secondary vent or a different configuration. Johnston also enforces frost-depth rules: any drain line leaving the home must slope to daylight or tie into the municipal sewer system properly, with no horizontal runs exposed above grade (frost depth is 42 inches in Johnston). If you're moving a toilet and the existing drain cannot be reused, you may need to core through the basement or crawlspace and slope the line toward the sewer, a $2,000–$5,000 cost that surprises many homeowners. A licensed plumber (or owner-builder filing their own plan) must show the location of all new drains, vents, and trap arms on the permit application. Undersized drains or improper venting will be rejected at rough plumbing inspection.

Waterproofing for shower and tub work is a frequent rejection point. IRC R702.4.2 requires a waterproof membrane behind any tub or shower enclosure; if you're converting a tub to a shower, the membrane must cover the entire wall area to at least 72 inches above the floor (or 6 inches above the showerhead, whichever is higher). Johnston's inspectors will ask to see the specific waterproofing assembly on the permit plan — for example, cement board plus a liquid or sheet membrane, or a waterproof drywall system like Densarmor Plus with proper sealing. A common rejection is vague language like 'waterproof membrane' without specifying the material and installation method. Tile alone is not a waterproof barrier; the membrane must be behind the tile. If you're only replacing tile in an existing shower and not changing the assembly, no permit is needed. But if you're gutting the walls and re-lining the shower, you must file a permit and show the waterproofing detail.

The permit process in Johnston typically takes 2–5 weeks from filing to approval, depending on plan completeness. The Building Department reviews for code compliance and may issue comments (requests for more information or revisions) within 5–7 business days. If your plan is incomplete — for example, no electrical details, no plumbing vent diagram, or waterproofing not specified — you'll be asked to resubmit, which adds 5–10 days. Once approved, you'll schedule rough plumbing and rough electrical inspections (typically scheduled 2–3 days after you call in ready). After inspections pass, you can close walls and proceed to final inspection, which covers waterproofing, fixture installation, and electrical verification. Permit fees in Johnston range from $200 to $800, depending on the estimated valuation of the work. A full bathroom remodel (fixtures, finishes, electrical, plumbing) typically valued at $15,000–$40,000 will incur a $400–$600 permit fee, calculated as a percentage of the declared project cost. If you undervalue the work to reduce the fee, the Building Department can revise the valuation based on square footage and scope, potentially increasing the fee and triggering an audit.

Three Johnston bathroom remodel (full) scenarios

Scenario A

Vanity and tile swap only — existing location (West Des Moines Ave, ranch home, 1970s)

Your 1970s ranch has a small single-sink bathroom. You want to replace the dated vanity with a new 36-inch unit (same location), re-tile the shower walls and floor (existing tub stays in place), and upgrade the light fixture. This is surface-only cosmetic work. The sink outlet, drain, and supply lines remain in the same location; the shower valve and drain are unchanged; no new circuits are needed (light is on the existing circuit). Johnston does not require a permit for this scope. However, because your home was built before 1978, you should hire a lead-safe contractor or follow EPA RRP (Renovation, Repair, and Painting) rules when disturbing existing surfaces. If you opt to re-waterproof the shower with a new membrane (going beyond just re-tiling), that triggers a permit because you're modifying the assembly. If you stay with surface work only — remove old tile, install new tile over the existing waterproof layer — no permit is needed. Total cost: $3,000–$8,000 for materials and labor (vanity $400–$1,000, tile $800–$2,000, light $150–$400, labor $1,500–$4,000). No permit fees. Timeline: 3–5 days once contractor is engaged.

Scenario B

Toilet and sink relocation plus new exhaust fan — Merle Hay neighborhood colonial, 1990s

Your 1990s colonial has a bathroom with the toilet on the north wall and sink on the east wall. You want to move the toilet to the east wall (next to the relocated sink) to create more floor space and add a new exhaust fan with ductwork venting through the roof. This scope requires a permit. The toilet relocation involves a new drain line and new supply lines; the sink relocation requires new supply and drain; the exhaust fan requires new electrical (likely a dedicated 15-amp circuit) and ductwork. You'll file a bathroom remodel permit with separate plumbing and electrical plans. The plumber must show the new toilet and sink drain locations, confirm that trap arms do not exceed 42 inches to the vent stack, and specify the vent routing (secondary vent if needed). The electrician must show the new circuit for the exhaust fan, including GFCI/AFCI protection per IRC E3902 (though a fan alone typically does not need GFCI, the bathroom circuit must still be AFCI-protected). Johnston's Building Department will review the plans for approximately 7–10 business days, then issue either approval or comments. If the plumber's trap arm design is too long or the ductwork doesn't terminate properly (must exit to open air, not into an attic or soffit), the plan will be rejected. Once approved, rough plumbing inspection (checking drain and supply rough-in), rough electrical inspection (circuit and fan roughing), framing inspection (if walls are moved), and final inspection (fixture installation, ductwork sealed, electrical trim) are required. Total cost: $8,000–$16,000 (fixture relocation labor $3,000–$6,000, ductwork $500–$1,200, electrical $1,000–$2,000, new finishes $3,000–$7,000). Permit fee: approximately $350–$500. Timeline: 3–5 weeks from filing to final inspection.

Scenario C

Tub-to-shower conversion with wall relocation — suburban split-level, master bath, 1980s

Your 1980s split-level has a cramped master bathroom with a tub alcove (tub on north wall, standard ceramic tile). You want to demo the tub, move the south wall out by 18 inches to enlarge the space, and install a large walk-in shower with a new waterproof membrane, frameless glass enclosure, and thermostatic mixing valve. This is a full-scope bathroom remodel requiring a permit. The tub-to-shower conversion alone triggers a permit (IRC R702.4.2 waterproofing assembly change); adding the wall relocation makes it a structural permit as well. You'll file a bathroom remodel permit plus a framing/structural permit. The plumbing plan must show the new drain location (if the shower base moves), the new supply rough-ins, the thermostatic valve spec (required for safety), and trap arm length confirmation. The electrical plan must show GFCI/AFCI protection for the bathroom circuit and any new lighting or heated-floor circuits. The framing plan must show the new wall location, header sizing, and relation to existing structure (floor joists, roof load if applicable). The waterproofing plan must specify the membrane type — for example, cement board substrate with a liquid-applied membrane plus a shower-pan liner, or a waterproof drywall system like Schluter or Kerdi — with installation details. Johnston's Building Department will conduct a full plan review (7–10 business days), issue comments, and may request a structural engineer's stamp if the wall relocation affects load paths. Rough plumbing, rough electrical, framing inspection (wall in place), waterproofing inspection (before tile), and final inspection are required. If the original toilet or vanity are also being relocated as part of the scope, those must be shown on the plumbing plan. Total cost: $20,000–$45,000 (wall relocation $4,000–$8,000, tub demo and disposal $500–$1,000, shower base and glass enclosure $3,000–$8,000, waterproofing and tile $4,000–$8,000, plumbing and electrical $3,000–$6,000, finishes and hardware $2,000–$5,000, labor and contingency $3,000–$9,000). Permit fees: $550–$800 (bathroom remodel) plus additional fee for structural work (typically $150–$300). Timeline: 4–6 weeks from filing to final inspection due to structural review and multiple inspection points.

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Waterproofing and tub-to-shower conversions in Johnston bathrooms

If you're converting a bathtub to a shower, IRC R702.4.2 requires a waterproof membrane assembly behind all tile or surface material. This is one of the most commonly failed inspection points in Iowa bathrooms because homeowners and some contractors assume tile alone is waterproof — it is not. Tile is porous and water will wick through the grout and behind the tile into the substrate, causing rot and mold within months or years. Johnston's inspectors will ask to see the specific membrane system on your permit plan before rough framing is approved.

Common approved assemblies include cement board (1/2-inch minimum) with a liquid-applied membrane like Redgard or Kerdi-Fix, or a sheet membrane like Kerdi or Ditra behind the tile. Some contractors use traditional felt paper with tar, which is outdated and often rejected. Waterproof drywall systems (Densarmor Plus, Mold-Armor, or equivalent) can work in some cases, but check with Johnston Building Department beforehand — some inspectors prefer cement-board-plus-membrane for showers because it has a longer track record. The membrane must cover the entire wall area from floor to at least 72 inches high, plus 6 inches above the showerhead if it's higher. The corners and seams must be sealed per the manufacturer's instructions. If you're using a curbed shower pan (traditional), the pan liner must be properly sloped (typically 1:4 minimum) to drain toward the drain opening, and the curb must be framed and sloped correctly — this is another frequent failure point.

The permit application must include a waterproofing detail — a sketch or written specification showing the substrate, membrane type, and installation method. 'Waterproof membrane' alone is not specific enough; the inspector needs to know whether it's a liquid, sheet, or hybrid system, and the exact product. You can attach product data sheets or installation instructions to the permit application. If you hire a tile contractor or waterproofing specialist, have them provide a written specification or shop drawing and include it with your permit documents. This small step will prevent plan rejections and delays.

Electrical and GFCI/AFCI requirements for Johnston bathrooms

Johnston enforces IRC E3902, which mandates GFCI (ground-fault circuit interrupter) protection for all bathroom outlets within 6 feet of a sink, tub, or shower. This means every outlet in your bathroom — including the exhaust fan circuit if it has an outlet, and any wall outlets near the sink vanity — must be GFCI-protected. Additionally, all branch circuits serving the bathroom (not just the outlets in the room, but the entire circuit) must have AFCI (arc-fault circuit interrupter) protection. This is a common source of confusion: a GFCI outlet or breaker protects against ground faults (water-related shocks), while an AFCI breaker protects against arc faults (sparks from loose wiring or damaged insulation that could cause fire). Many homes have a GFCI outlet at the bathroom sink, but the entire circuit may lack AFCI protection — this is a code violation in new work or major remodels. The solution is to install an AFCI breaker in the main electrical panel for the bathroom circuit, or use combination AFCI/GFCI breakers (or devices).

If you're adding a new exhaust fan, the fan motor and control switch typically do not need GFCI protection (the fan is not a utilization outlet), but the bathroom branch circuit must still have AFCI protection. If you're adding a heated floor mat or radiant heater, that circuit also needs AFCI protection and a thermostat. The electrician's permit plan must show the AFCI and GFCI protection clearly — specify whether it's a breaker, outlet, or combination device, and label the circuits. If you are an owner-builder, you can do the electrical work yourself, but Johnston will require you to pull a permit and have the work inspected; you must also show a plan (even a rough diagram) of the circuits and protection devices. If you hire a licensed electrician, they will pull the permit under their license and design the circuits; you'll need to provide them with copies of the permit documents for your records.

A practical note: if you're relocating the bathroom sink or adding fixtures, the electrician's plan must also account for outlets behind or under the new vanity. Building code requires at least one outlet in the bathroom (typically at the vanity); if you're relocating the vanity, the outlet must move with it or a new one must be installed. Similarly, if you're adding a heated towel rack, exhaust fan with humidity sensor, or ventilation light, each may require its own circuit or a shared circuit with proper protection. Design the electrical layout early in the remodel process, in coordination with the plumber and general contractor, to avoid conflicts between wiring runs and plumbing lines.

City of Johnston Building Department
6015 Merle Hay Road, Johnston, IA 50131
Phone: (515) 278-5851 (main city line; ask for Building Department) | https://www.cityofjohnston.com/departments/building-development (verify permit portal URL on city website)
Monday–Friday, 8:00 AM–5:00 PM (Central Time); closed weekends and city holidays

Common questions

Can I do my own plumbing and electrical work on a bathroom remodel in Johnston?

Yes, if you are the homeowner and the home is your primary residence, you may qualify as an owner-builder under Iowa Building Code. You can perform plumbing and electrical work yourself, but you must pull a permit, provide plans or diagrams to the Building Department, and pass required inspections. If you hire contractors, they must be licensed (or you assume the role of owner-builder). Check with the Johnston Building Department to confirm owner-builder eligibility for your specific project.

What is the estimated permit fee for a full bathroom remodel in Johnston?

Permit fees in Johnston are typically calculated as a percentage of the estimated project valuation. A full bathroom remodel valued at $15,000–$40,000 will incur a permit fee of approximately $300–$600. The Building Department will confirm the fee when you file the permit application based on the scope and estimated cost. If your project includes structural work (wall relocation, framing changes), additional fees for framing and structural permits may apply.

Do I need a permit just to replace my toilet or bathroom faucet in Johnston?

No. Replacing a toilet, faucet, or other fixture in the same location without moving supply or drain lines does not require a permit. This is considered maintenance or cosmetic work. If you are relocating the fixture or changing the drain configuration, a permit is required.

What should I do if my home was built before 1978 and I'm remodeling the bathroom?

Homes built before 1978 are assumed to contain lead-based paint. When you disturb painted surfaces (drywall, trim, fixtures), you must follow EPA RRP (Renovation, Repair, and Painting) rules, which require certified contractors, containment, and proper disposal of lead-contaminated dust. This is not a permitting requirement, but it is a federal law. Hire a lead-safe contractor or obtain RRP certification yourself. The Building Department may ask about lead compliance during permit review.

How long does it take to get a bathroom remodel permit approved in Johnston?

Plan review typically takes 5–10 business days if your plans are complete and compliant. If the Building Department issues comments or requests revisions, add 5–10 days for resubmission and re-review. Once approved, scheduling inspections (rough plumbing, rough electrical, framing, final) typically takes 2–4 weeks, depending on your contractor's readiness and inspector availability. Total timeline from filing to final approval is usually 4–6 weeks.

Can I move my bathroom toilet to a different wall in Johnston?

Yes, but you need a permit. Moving the toilet requires a new drain line and new supply lines, both of which are regulated by code. The drain line must be properly vented (IRC P2706 limits the trap arm to 42 inches), and the line must slope toward the sewer or septic system and conform to frost-depth requirements (42 inches in Johnston). A licensed plumber or qualified owner-builder must design the new drain run and show it on the permit plan.

What happens if the Building Department rejects my bathroom remodel plans?

If the plans do not meet code or lack required details, the Building Department will issue written comments listing the deficiencies. Common rejections include missing GFCI/AFCI details, waterproofing assembly not specified, trap arm length exceeding code, or incomplete plumbing/electrical drawings. You (or your contractor) must revise the plans, address the comments, and resubmit. Resubmission typically takes 5–10 days for re-review. Most plans are approved on the second or third submission; thorough planning upfront (with a contractor or designer) minimizes rejections.

Do I need a separate permit for adding a new exhaust fan to my bathroom?

No. Adding an exhaust fan is part of the bathroom remodel permit scope, not a separate permit. However, the exhaust fan work must be included in the initial permit application — show the ductwork routing, termination location (must exit to open air), and electrical circuit on the plumbing and electrical plans. If the fan includes a humidistat or integrated light, the electrical plan must specify the circuit type and controls.

What is a trap arm and why does it matter for my bathroom remodel?

A trap arm is the horizontal section of drainpipe between a fixture outlet (toilet, sink, tub) and the vent stack. IRC P2706 limits trap arm length to 42 inches; if your bathroom layout requires a longer run, the drain line must include a secondary vent or a different configuration (such as an Island Vent or wet vent). The inspector will verify trap arm length during rough plumbing inspection. If the run is too long, you'll be asked to revise the plumbing design, which can require rerouting under the floor or wall — a costly change. Work with your plumber to confirm trap arm distance during design to avoid surprises.

What inspections will I need to pass for a full bathroom remodel in Johnston?

Typically: rough plumbing (drain, vent, and supply lines in place before walls are closed), rough electrical (circuits and protection devices in place), framing (if any walls are moved), waterproofing (membrane installed and tested if required), and final inspection (all fixtures installed, electrical trim complete, waterproofing verified). If you are only replacing fixtures in place and not moving walls or changing systems, you may only need a final inspection. The Building Department will specify required inspections when the permit is approved.

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 Johnston Building Department before starting your project.

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