How much does it cost to add a second bathroom in a New Brunswick home?

Adding a second bathroom to an NB home typically costs $25,000-$55,000, depending on whether it's a full bath or a half-bath, the complexity of running new plumbing, and your chosen finishes. A simple half-bath addition in existing finished space runs $15,000-$25,000; a full bathroom with a tub/shower, toilet, and vanity in a space that requires new plumbing rough-in runs $30,000-$55,000.

The single biggest cost driver in adding a bathroom is plumbing — specifically, how far the new bath is from your existing drain stack and water supply lines. Plumbing work in NB falls under TSANB (Technical Safety Authority of NB) jurisdiction, which means all rough-in must be done by a licensed plumber and inspected before walls are closed. If you can locate the new bathroom directly above or adjacent to an existing stack, the plumbing rough-in stays manageable at $5,000-$10,000. If you're adding a bathroom in a basement corner far from any existing drain, you may need to break concrete and run new drains, pushing rough-in costs to $12,000-$18,000 on their own. A sewage ejector pump adds another $2,000-$4,000 if gravity drainage isn't possible.

On top of plumbing, electrical work is a required part of every NB bathroom addition — a dedicated 20-amp circuit for the bathroom, GFCI outlets, and exhaust fan wiring all require a licensed electrician and TSANB electrical inspection. Expect $2,000-$4,000 for bathroom electrical work. In older NB homes with 60-amp or 100-amp panels that are already near capacity, a panel upgrade may be required, adding $2,500-$5,000 to the project.

A building permit is required for adding a bathroom anywhere in NB — you're adding plumbing, electrical, and potentially modifying structural elements. In Moncton, Saint John, Fredericton, and other incorporated municipalities, apply through the city building department. In rural NB, go through your Regional Service Commission. Budget $150-$400 for permit fees and plan for inspections at rough-in and completion stages.

For the bathroom finishes themselves, a mid-range NB bathroom addition might include a standard alcove tub with tiled surround ($3,000-$6,000), a vanity with sink ($800-$2,500), toilet ($300-$700), tile floor ($1,500-$3,000), and lighting and accessories ($500-$1,500). Premium finishes — walk-in tile shower, floating vanity, heated floors, designer tile — can add $10,000-$20,000 to the finish budget alone.

NB-specific considerations matter significantly here. If you're finishing a basement bathroom, the spring snowmelt season (April through June) raises hydrostatic pressure against NB foundations — any basement bathroom must include proper floor waterproofing and a reliable sump pump system before any finishing work begins. Mould in a basement bathroom is almost guaranteed if moisture issues aren't addressed first. For second-floor bathroom additions, the floor structure may need reinforcement to carry the weight of tile and a full bathtub — this is a structural assessment your contractor should complete before rough-in begins.

Budget a 15-20% contingency on any bathroom addition — it's common to open walls and discover outdated knob-and-tube wiring, asbestos pipe insulation in pre-1990 NB homes, or undersized drain lines that need upgrading to current code. These discoveries are genuinely difficult to predict until demolition begins. Getting 3+ quotes from experienced NB renovation contractors and asking each one specifically what they include for plumbing, electrical, and permit coordination will help you compare apples to apples.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• Thirty Four Renovations
• Gionetterenovations