Do I need a permit for a full bathroom remodel in
Dover, New Hampshire?

Dover bathroom remodels — the key details

The threshold for a permit in Dover is any remodel that involves relocating plumbing fixtures, adding or modifying electrical circuits, installing a new exhaust fan with ductwork, or changing the type of water-containment assembly (tub to shower conversion, for example). New Hampshire's 2015 IBC adoption (RSA 21:34-a) requires that all plumbing and electrical work in bathrooms conform to the current code, which means if you're moving a toilet or vanity drain more than a few feet, running new electrical circuits, or installing a new GFCI-protected outlet, you need a permit. Dover's Building Department interprets these rules straightforwardly: if it requires licensed trades, it requires a permit. The one gray area homeowners often encounter is whether swapping out a single-piece vanity for another (same location, same rough plumbing and electrical) is a permit job—it is not, as long as you're using the existing rough plumbing and outlets. But if you're relocating the vanity to a new wall or adding new outlets, a permit is required.

Plumbing code requirements for full bathroom remodels in Dover follow IRC P2706 and New Hampshire amendments. The most common rejection points are drainage-fitting specifications and trap-arm length. When you relocate a toilet or sink drain, the trap arm (the horizontal pipe between the trap and the vent stack) cannot exceed 6 feet without a vent loop, and the slope must be 1/4 inch per foot of horizontal run. If your bathroom is on a slab or on the first floor of a two-story home with limited access to the main vent stack, this can force you to install a new vent line—a cost-adder of $800–$2,500 depending on routing. For shower and tub rough-in, you must specify the valve type (pressure-balanced or thermostatic) and include it on the rough-plumbing plan; undersized or unbalanced valves are a common reason Dover's inspectors request changes before sign-off. Waterproofing for shower/tub areas requires a lined assembly: either a pre-formed acrylic pan with cement-board walls and a waterproof membrane, or a fully lined pan with tile. Simply tiling over drywall is not compliant and will be flagged during rough inspection.

Electrical work in Dover bathrooms must conform to IRC E3902 and New Hampshire amendments, which mandate GFCI (ground-fault circuit interruption) protection on all receptacles and lighting circuits within 6 feet of sinks and within the tub enclosure. AFCI (arc-fault circuit interrupter) protection is also required on all bedroom circuits, which often includes a small ensuite bathroom—this can mean upgrading your breaker panel or installing combination GFCI/AFCI devices. If you're adding a new exhaust fan, it must be ducted to the outdoors (not into an attic or soffit) with a damper and screened termination; ductwork sizing is typically 4 inches for a 50–80 CFM fan, larger if you're combining multiple exhaust points. Dover's inspectors will ask to see the duct routing and termination on your electrical plan—vague descriptions like 'vented to roof' will be rejected. New lighting, outlets, and switches in the bathroom are required to be on a dedicated 20-amp circuit (not shared with other rooms), and all switches must be 3-way rated if controlling multiple lights. Plan to budget an additional 6–10 hours of electrician labor to design and route new circuits if you're adding exhaust and new outlets.

Structural and framing work, though often minimal in a bathroom remodel, is still inspected in Dover if walls are moved, windows enlarged, or ceiling openings created (for exhaust vents or skylights). If you're removing a load-bearing wall—rare in a full bath, but possible in larger master bathrooms—you must submit calculations for a header and lateral-bracing details; this typically requires a structural engineer and adds $1,500–$3,000 to your project cost. For non-load-bearing partition walls, framing inspection is often waived if drywall is hung after the rough-in inspection. One Dover-specific detail: the city does not have a separate 'drywall inspection' step for interior remodels; drywall is inspected as part of the final inspection, so your drywall must be finished (mudded, taped, and primed if not tiled) before final sign-off. If you're leaving drywall visible (not tiling), it must be moisture-resistant (greenboard or cement board) in wet areas, which Dover inspectors will verify.

Permit costs in Dover range from $275 to $600, calculated as approximately 1.5% of the declared project valuation (with a minimum fee). A full bathroom remodel with fixture relocation, new electrical, and exhaust installation typically runs $8,000–$20,000 in declared value, putting your permit fee at $350–$500. The city charges separate inspection fees for plumbing, electrical, and final: typically $75–$125 each, so budgeting an additional $300–$400 in inspection fees on top of the permit is realistic. Plan review typically takes 10–14 days for straightforward projects submitted via the online portal; resubmissions due to missing details or code questions add 5–7 days per resubmission. Once approved, you can begin work, but inspections must be scheduled and passed in sequence: rough plumbing first, rough electrical second, then final inspection (framing/drywall/finish). Total timeline from permit submission to final sign-off is typically 4–6 weeks, assuming no major rejections. If you're hiring a licensed plumber and electrician (recommended), they may handle permit coordination and inspections as part of their contract, which simplifies the process.

Three Dover bathroom remodel (full) scenarios

Why exhaust-fan ductwork is a frequent rejection point in Dover permits

Dover's Building Department specifically requires exhaust-fan ductwork to be routed to the outdoors with a damper and screened termination, and this requirement appears in their standard rejection list for bathroom remodels. The reason is humidity: an improperly vented bathroom fan dumping into an attic or soffit creates moisture accumulation, which leads to mold, wood rot, and eventual structural damage. New Hampshire's humid summers and wet springs make this particularly critical in climate zone 6A. Your permit drawings must specify the duct diameter (typically 4 inches for a 50–80 CFM fan), the routing path (including any bends or elbows, which reduce flow), and the termination point (roof, gable wall, or soffit—but only a roof or wall termination is code-compliant; soffit discharge is a rejection trigger).

If you're installing an inline fan (ducting runs through the attic to a roof vent), you must specify the duct material (rigid metal preferred, not flexible plastic, which is prone to compression and mold growth), insulation (if the duct passes through an unconditioned attic, it should be insulated to prevent condensation), and the length. Duct runs longer than 25 feet require oversizing or a booster fan, which adds cost. Many DIYers or budget contractors route ducts to the attic or soffit 'temporarily,' planning to finish later—this is a code violation and Dover inspectors will flag it at rough inspection and require correction before final sign-off. Building in the proper duct termination at the outset costs $300–$800 more but saves the rejection cycle.

Dover's online permit portal has a specific field for 'exhaust fan ductwork termination'—fill it in clearly with the roof or wall location, duct diameter, and damper type (gravity damper is standard). If you leave it blank or write 'vented to roof,' expect a request for clarification. Including a simple sketch showing the duct path from the fan to the roof vent (with bends and distances noted) speeds plan review and prevents a rejection round.

Waterproofing strategies and Dover's inspection reality for shower conversions

When converting a tub to a shower or building a new tile shower in a Dover bathroom, you have two primary waterproofing strategies, and Dover inspectors care deeply about which one you choose because it determines how long the installation lasts and whether mold and rot become future problems. The first is a prefabricated acrylic or fiberglass shower pan (Kohler, Maax, or similar), installed over a mortar bed or leveling layer, with cement-board walls and a waterproof membrane (Kerdi Board, Redgard, or sheet-membrane systems) applied over the cement board before tile. This is the most common approach and the safest for inspectors: the pan is tested and rated, the membrane is a known product, and the assembly is straightforward. The second approach is a fully lined system without a hard pan—waterproof membranes (like Schluter or Wedi systems) that create a complete shower enclosure with integrated curbs and slopes, tiled over without a separate mortar pan. This is more expensive ($2,000–$4,000 for materials alone) but creates a monolithic waterproof envelope.

Dover inspectors have seen mold problems from tiled showers that lacked proper membrane—water soaks through grout and tile, sits behind the cement board, and causes rot within two to three years. For this reason, they will not pass a final inspection on a shower without verifying that a waterproof membrane is installed. You must bring the product spec sheet and installation instructions to the rough inspection so the inspector can confirm that the material meets IRC R702.4.2 (waterproofing requirements for wet areas). Most critical: do not install tile directly over drywall in a shower enclosure, even if you 'waterproof' the drywall with paint. This will be rejected, and you'll have to remove the tile and install cement board plus membrane before re-inspection.

Cost implications: a proper acrylic pan plus cement board plus Redgard or Kerdi membrane adds $1,200–$2,000 to your material costs compared to just a pan and drywall. But this is non-negotiable code compliance, and skipping it creates a future problem (mold, rot, or water damage within a few years) that insurance may not cover. Dover's inspectors are experienced enough to spot shortcuts, so plan for proper waterproofing in your budget and timeline.

Common questions