A bathroom is the smallest room in most houses and the one with the most trades in it. Demolition, framing, plumbing, electrical, ventilation, waterproofing, tile and finish carpentry all happen in a space of 40 or 50 square feet, often in a house in Nashua, Dover or Concord that has had three or four bathrooms in the same spot since it was built. Getting the sequence and the people right is most of the job.
The remodeler needs no license; the people inside the walls do
New Hampshire does not license remodelers, and it has no contractor registry. The trades that go behind the wall are a different matter. Plumbing, gas fitting and electrical work in someone else's home all require a state license under RSA 153:29 and the electricians' statute, and a company doing plumbing needs its own business license too.
So the useful question for a remodeler in Hudson or Durham is not "are you licensed" but "who does your plumbing and electrical?" Get the names and license numbers in the contract and look them up on the OPLC verification page. Some remodeling firms have a licensed plumber on staff; most subcontract. Either is fine, as long as the licensed person is the one doing and signing for the work.
A homeowner may do their own plumbing and wiring in their own single-family house. If you plan to handle part of the job yourself, write down exactly where your work ends and the remodeler's begins, so a leak in the wall does not become an argument about whose joint it was.
Permits from a Manchester bath to a town with no inspector
Whether a bathroom needs a building permit, and which trade permits, depends on the town and on what changes. Manchester's building division lists "When do I need a permit?" on its Building FAQ; moving fixtures, adding a circuit or opening a wall usually does. Many small towns in the Monadnock and Lakes regions have no building inspector, and in those places there may be no local permit at all.
Either way, the plumbing and electrical should be done to code and, where a town inspects, inspected before the walls close. Put in the contract that the remodeler is responsible for obtaining any permits the town requires and for scheduling the inspections. Ask the remodeler to show you the rough plumbing before the drywall goes up, even if no inspector will.
Pre-1978 bathrooms and lead-safe demolition
Bathrooms in older houses are full of painted surfaces: window trim, door casings, beadboard, plaster walls. In any house built before 1978, cutting, sanding or demolishing them can release lead dust. The federal Renovation, Repair and Painting rule requires firms doing that work for pay in pre-1978 homes to be certified and to follow lead-safe practices: containment, plastic sheeting, cleanup and verification.
Ask the remodeler for their RRP firm certification. Ask how they will seal the bathroom from the rest of the house, especially if children live there.
New Hampshire added its own rule in 2024 for one case. If you are turning a pre-1978 house, or part of it, into a rental, RSA 130-A:5-d requires a lead-safe certificate from a licensed risk assessor before a tenant moves in. That applies to a new rental conversion, not to your own home, but an owner in Keene or Swanzey finishing a bathroom in an accessory apartment should know about it before the tile goes on.
Venting, moisture and the small baths of older houses
Older bathrooms in Nashua, Pelham or Concord were often built with a window and no fan. A modern remodel almost always adds an exhaust fan, and where the duct ends matters. A fan that dumps humid air into the attic will frost the roof sheathing in a New Hampshire winter and cause rot and mold over a few years. Ask the remodeler where the duct will terminate and whether it will be insulated where it crosses a cold attic.
Waterproofing is the other hidden piece. Tile and grout are not waterproof. Ask what membrane will go behind the tile in the shower and on the floor, how the shower pan will be built and tested, and whether the remodeler will flood-test the pan before tiling.
If your water heater is due for replacement, a remodel is a good moment to think about it. NHSaves pays $900 in 2026 for a qualifying heat pump water heater, though the unit needs space and air and usually lives in a basement rather than a bath.
Planning a bath you can use at 80
Many New Hampshire remodels are done by owners planning to stay put, and a few choices made now are cheap compared with retrofitting later. A curbless or low-threshold shower needs the floor framing recessed or the pan sloped from the start; it cannot easily be added once tile is down. Grab bars need solid blocking in the wall, and the time to add that blocking is when the studs are open, even if the bars go on years from now. A wider door, a comfort-height toilet, a handheld shower on a slide bar and a bench in the shower all fit inside a normal remodel budget if they are in the first drawing.
Ask the remodeler whether they have built curbless showers before and how they handle the drain and slope. Ask for blocking locations to be photographed before drywall, so whoever installs the bars later knows where to drill.
Condos and two-families in the Seacoast and Merrimack Valley
If your bathroom is in a condo in Portsmouth or Newmarket, or in one unit of a two-family in Manchester, two extra things come into play. First, the association or the other unit's owner may have rules about working hours, water shutoffs, noise and which contractors may work in the building, and a shared stack or water main may mean someone else loses water while yours is being worked on. Get the association's approval in writing before demolition.
Second, the owner exemptions for plumbing and wiring are written for your own single-family home or townhouse. In a multi-unit building, assume the plumbing and electrical must be done by licensed people, and plan the budget that way.
Budgeting $24,200 to $39,600 and paying in stages
A typical New Hampshire bathroom remodel runs about $24,200 to $39,600 in the New Hampshire bathroom remodel cost estimate. A small hall bath in Litchfield with the layout unchanged sits near the bottom. A primary bath with a tiled walk-in shower, a double vanity and radiant floor heat sits near the top or past it.
The single biggest driver is moving things. Relocating a toilet means moving a 3-inch drain and its vent, which can mean cutting joists or opening the ceiling below. Keeping the fixtures where they are saves real money.
There is no state rule on deposits, so set a schedule that follows the work: a first payment for ordering fixtures and tile, then payments at rough-in, at tile and at completion. Keep the last payment until the punch list is finished and any inspection is closed. Allowances for tile, vanity and fixtures should be written as numbers, and you should know what each one actually buys.
