Do I need a permit for a full bathroom remodel in
Columbus, Indiana?

Columbus bathroom remodel permits — the key details

The permit threshold in Columbus is determined by scope, not cost. If you are only replacing a faucet, vanity, toilet, or light fixture in place — no new wiring, no new plumbing runs, no wall moves — you do not need a permit. But the moment you relocate a toilet, sink, or tub to a new wall; add a new exhaust-fan duct; run a new electrical circuit; or convert a tub to a shower (which requires a new waterproofing assembly under IRC R702.4.2), you must pull a permit. Columbus Building Department staff will ask you directly on the intake form: Are you moving any plumbing fixtures? Adding electrical circuits? Installing new ventilation? Your honest answer determines the permit requirement. Many homeowners assume a full gut remodel always needs a permit — it does if fixtures move, but not if you're only stripping and replacing finishes in the same footprint.

Electrical work is the second-biggest trigger. Any new circuit — for a heated floor, towel warmer, exhaust fan, or additional outlets — requires a permit and inspection under NEC Article 210 and 220. Columbus Building Department enforces the 2020 NEC, which mandates GFCI protection on all bathroom circuits within 6 feet of a sink or tub (NEC 210.8(A)(1)). Your electrical rough-in must show this on the permit plan. If you're simply replacing an existing light or outlet in the same box without adding capacity, that's exempt. But 9 out of 10 full bathroom remodels add at least one circuit — for the exhaust fan, for example — so plan on the permit from the start.

Exhaust-fan installation is almost always a permitted item in Columbus. The fan itself must be rated for bathroom use (usually 50–100 CFM for a typical 5x8 bathroom), and the duct must terminate outside — not into the attic, not into a soffit. IRC M1505.2 requires the duct to exit the building enclosure and terminate with a damper. In Columbus's 5A climate, your ductwork routing matters: if you're terminating through an exterior wall, the duct should be insulated (IRC M1505.3 doesn't strictly mandate it, but condensation in a cold duct is a moisture headache). The permit will ask for duct size, material, and termination location. Improperly ducted exhaust fans are one of the top rejection reasons — auditors see too many fans vented into attics or via soffit vents.

Waterproofing for tub-to-shower conversions is non-negotiable. If you're removing a tub and installing a walk-in shower, IRC R702.4.2 requires a continuous waterproofing membrane on the floor and walls behind the tile. Columbus inspectors will ask: Is this cement board plus shower pan liner, or a pre-made waterproof base? You must specify the waterproofing system on your permit plan — vague answers get rejected. The most common approach is cement board (not regular drywall) plus a peel-and-stick or brushable waterproof membrane; poured schluter or Kerdi systems are also acceptable. The waterproofing layer must extend at least 12 inches up the wall on all four sides and cover the entire floor. This is tested during rough-framing inspection (before tile), so don't tile over untested waterproofing.

Plan-review timelines in Columbus average 2–3 weeks for full-scope permits, but over-the-counter simple permits can be issued same-day. If your bathroom remodel includes fixture relocation, you'll need plan review; if it's surface-only, you may walk out with a permit the same day. Inspection sequence is typically: rough plumbing (if new drains), rough electrical (if new circuits), framing (if walls move), and final (after all finishes). Drywall inspection is often waived if no structural changes occur. Budget 4–6 weeks from permit to final sign-off, assuming no rejections. Columbus Building Department is generally responsive if plans are clear — fuzzy drawings or missing details (like that shower-waterproofing spec) will delay you by another 1–2 weeks.

Three Columbus bathroom remodel (full) scenarios

Waterproofing for shower conversions: why Columbus inspectors are strict

When you convert a tub to a shower in Columbus, you're not just removing a fixture — you're changing the water-entry risk profile of the wall assembly. A tub rim holds water; a shower wall doesn't. Water sprayed directly on drywall will wick, rot studs, and create mold behind tile within months. IRC R702.4.2 mandates a continuous, impermeable membrane. Columbus inspectors have seen too many bathrooms where homeowners tile directly over unprotected drywall or cement board, then watch the wall rot from inside. The standard fix is cement board (not regular drywall) plus a peel-and-stick or spray-applied waterproof membrane (Schluter Kerdi, Tile-Mate, or similar) extending at least 12 inches up all four walls and covering the entire floor.

Your permit plan must name the waterproofing system by brand or type. 'We'll waterproof it' is rejected; 'Cement board plus Schulter Kerdi' is approved. Columbus Building Department will schedule a rough-framing or rough-plumbing inspection to verify the membrane is in place before drywall tape or tile goes on — this can't be inspected after finish. If the inspector finds bare drywall under the tile, the tile comes off and the assembly is redone (a $1,500+ do-over). Columbus's 5A climate makes this worse: freeze-thaw cycles exploit any water intrusion, and humidity in winter creates condensation on cold walls. Spend the $200–$400 on a proper waterproofing membrane and avoid the catastrophe.

For tub-to-shower conversions, the pan liner or base is critical. A pre-sloped Schluter Kerdi base with a drain outlet is foolproof; a tiled floor over membrane with a linear or point drain requires careful slope and membrane detailing. Both are code-compliant. The permit doesn't prescribe which, but Columbus inspectors will ask: How is water reaching the drain without pooling? Your answer should be clear (e.g., 'Schluter pre-formed base with 1/4-inch slope to center drain, Kerdi membrane on walls'). Vague sketches get rejected. Include a detail drawing on your permit plan — it costs you an extra 10 minutes and saves 2 weeks of rejection cycles.

Exhaust-fan routing and ductwork in Columbus's cold winters

IRC M1505 requires bathroom exhaust fans to terminate outside the building enclosure — not in the attic, not into a soffit. Columbus Building Department enforces this strictly because of Ohio moisture and winter condensation risk. A fan ducted into an attic will deposit warm, moist air into an unheated space, where it condenses on rafters and insulation, leading to mold and structural rot. Even soffit vents (which look tidy from outside) are problematic: bathroom moisture backs up into the soffit, condenses on the back side of the soffit panel, and rots the tail ends of the roof trusses. Your permit plan must show the duct exiting the building envelope — either through an exterior wall with a terminating hood and damper, or through the roof with a roof cap and damper.

Duct sizing matters. A typical 5x8 bathroom requires 50–100 CFM; use a 4-inch duct. If you run a 3-inch duct or undersize the fan, static pressure builds, the fan runs inefficiently, and moisture escapes through wall cracks instead. Your permit plan should specify: duct diameter, fan CFM rating, and termination location (e.g., 'East exterior wall, 12 inches above grade, with damper'). Columbus inspectors will ask: Where does this duct go? If the answer is 'we'll figure it out during construction,' the permit is rejected. You must know the routing before you file.

Insulation of the duct itself is not mandated by IRC M1505, but Columbus is in a freeze-thaw zone (36-inch frost depth, 5A climate). An uninsulated 4-inch duct with warm, moist air running through it in winter will sweat on the cold exterior portion (outside the insulated wall cavity). Water drips back into the fan or bathroom. Insulating the duct (wrap it with 1-inch foam or use insulated flex duct) costs $50–$100 extra and prevents this problem. Many Columbus inspectors recommend it even if not required — it's cheap insurance. Include it in your plan or be prepared for a comment during inspection.

Common questions