How much does it cost to add a bathroom, bedroom, and living area to a basement in Fredericton in 2026?

A full basement conversion with a bathroom, bedroom, and living area in Fredericton typically runs $40,000 to $65,000 in 2026, depending on the size of the space, the condition of your foundation, and the level of finishes you choose. This is a mid-range to upper-mid-range project that transforms raw basement space into a functional living suite.

Breaking the budget down by component gives a clearer picture. The living area — framing, insulation, drywall, flooring, and painting for roughly 400 to 600 square feet — typically costs $15,000 to $25,000. For the bedroom, add $2,500 to $5,000 for the egress window (cutting through your foundation wall, installing the well, and the window itself), plus another $4,000 to $8,000 for framing, insulation, drywall, closet, and flooring. The bathroom is the most expensive single room, running $8,000 to $25,000 for a full three-piece — you are breaking through the concrete slab for drain lines, running supply plumbing, and installing fixtures. A basic three-piece with standard finishes sits around $10,000 to $15,000, while a high-end bathroom with tiled shower, heated floors, and premium fixtures pushes toward $20,000 or more.

On top of these room costs, budget for electrical rough-in at $2,000 to $5,000 (new circuits, GFCI-protected outlets throughout, AFCI on the bedroom circuit, recessed lighting), a drop ceiling at $2,000 to $5,000, and permits at $150 to $300 through the City of Fredericton building inspection department. Fredericton processes permits relatively quickly — typically one to three weeks — but you will need inspections at framing, rough-in, insulation, and final stages.

What Fredericton Homeowners Must Address First

Before any finishing work begins, waterproofing must be confirmed or addressed. Fredericton sits in the Saint John River valley with mixed clay and loam soils and a seasonally high water table, especially in low-lying neighbourhoods near the river. If your basement shows any signs of moisture — staining, efflorescence on the block walls, musty smell, or damp concrete — you need an interior waterproofing system ($3,000 to $8,000) or exterior membrane work ($8,000 to $20,000) before a single stud goes up. Finishing over a wet basement leads to mold, rot, and a complete tear-out within two to three years.

Also budget for radon testing before you close up the walls. New Brunswick has elevated radon levels in many areas, and a sub-slab depressurization system ($2,000 to $4,000) is far easier and cheaper to install before finishing than after. A three-month passive test kit costs $30 to $50 and should be placed in the lowest living area.

For insulation, use rigid foam board ($2.50 to $4.00 per square foot) or closed-cell spray foam ($4.00 to $7.00 per square foot) against foundation walls. Never use fiberglass batts directly against the foundation — they trap moisture between the batt and the cold concrete, leading to hidden mold. NB Building Code requires a minimum R-12.5 for basement walls, and R-20 is recommended for energy efficiency in our climate.

For flooring, luxury vinyl plank ($4 to $8 per square foot installed) over a Dricore subfloor system ($3 to $5 per square foot) is the best combination for Fredericton basements — waterproof, comfortable underfoot, and handles the humidity swings of our Maritime seasons.

A realistic all-in budget including waterproofing, radon testing, and a modest contingency lands most Fredericton homeowners between $45,000 and $70,000 for a bedroom, bathroom, and living area. Get at least three quotes — NB pricing varies 30 to 40 percent between contractors for identical scope. New Brunswick Basements can match you with local basement renovation contractors for free estimates on your project.

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

• Gionetterenovations
• Thirty Four Renovations