How much does it cost to add a second bathroom in a Vancouver basement suite?

Adding a second bathroom in a Vancouver basement suite typically costs between $15,000 and $35,000, with the plumbing rough-in and concrete work being the largest cost drivers. This is one of the more complex and expensive bathroom projects because you're creating an entirely new bathroom where plumbing infrastructure doesn't currently exist, rather than renovating an existing space.

The plumbing rough-in is the single biggest expense, typically running $4,000–$10,000. Adding a bathroom below grade requires cutting into the concrete floor slab to install new drain lines connecting to the building's main sewer line. This involves concrete cutting and removal ($1,500–$3,000), new drain piping installation for the toilet, shower or tub, and sink ($2,000–$5,000), and concrete patching after the plumbing is in place ($500–$1,500). If the basement suite doesn't have a sewage ejector pump and the new bathroom sits below the main sewer line elevation, you'll need one — a sewage ejector system adds $2,000–$5,000 installed. Supply lines (hot and cold water) are simpler to run, typically $800–$2,000.

Framing and walls for the new bathroom enclosure cost $1,500–$4,000 depending on the size and configuration. A basic three-piece bathroom (toilet, vanity, shower) needs approximately 35–50 square feet of floor space. Moisture-resistant drywall on non-wet walls, cement backer board in the shower area, and proper vapour barrier installation are all required.

Electrical work — which must be done by a licensed electrician — runs $1,500–$3,500. This covers a new dedicated circuit for the bathroom, GFCI-protected receptacles (code-required), an exhaust fan circuit, and lighting. The exhaust fan is particularly critical in a below-grade bathroom — you need a minimum 50 CFM fan ducted to the exterior, and given that basement suites already face higher humidity challenges in Metro Vancouver's climate, an 80–110 CFM fan is strongly recommended.

Fixtures and finishes make up the remaining $5,000–$15,000. A shower stall with acrylic base ($1,500–$3,500 installed) or custom tile shower with full waterproofing ($3,000–$8,000), a vanity with countertop ($800–$3,000 installed), a toilet ($400–$1,200 installed), tile flooring ($10–$25 per square foot installed), and paint bring the bathroom to a finished state.

Permits are mandatory for adding a new bathroom in Vancouver. You'll need a building permit, plumbing permit, and electrical permit from the City of Vancouver — combined fees typically run $400–$1,200. The City of Vancouver has specific requirements for basement suites under the Laneway House and Secondary Suite programs, and any new bathroom must meet BC Building Code requirements for ceiling height (minimum 6 feet 5 inches in bathrooms), ventilation, egress, fire separation, and plumbing code compliance. Inspections are required at multiple stages — rough-in plumbing, rough-in electrical, and final.

There are several Vancouver-specific factors that affect basement bathroom additions. The city's high water table, particularly in areas like the east side, Marpole, and Kerrisdale, means below-grade waterproofing is critical. The exterior foundation walls in the bathroom area should be inspected for moisture intrusion, and a drainage membrane or waterproofing coating may be needed ($500–$2,000). Vancouver's seismic zone requirements also apply — any heavy fixtures like wall-hung toilets or large mirrors must be properly anchored to structural framing.

Radon testing is recommended whenever you're cutting into a basement concrete slab. Parts of Metro Vancouver have elevated radon levels, and breaking the slab provides an opportunity to install a radon mitigation rough-in ($300–$800 during construction versus $2,000–$3,000 to retrofit later).

If the basement suite is a rental unit, the bathroom addition may need to comply with the City of Vancouver's secondary suite regulations, including specific requirements for fixture counts, ventilation, and fire separation. Check with the city's development services before beginning design work. A licensed plumber must handle all drain and supply rough-in, and all plumbing and electrical work requires inspection — this is not a project for DIY or unlicensed contractors. Always verify WorkSafeBC clearance for every contractor working on the project.