⚡ Quick Answer
Bathroom renovation plumbing costs $2,000-$8,000 in Toronto depending on whether you're replacing fixtures in place or moving them to new locations. Moving a toilet adds $1,500-$4,000 due to drain complications. Permits are required for any work that moves drains, water lines, or alters venting. Plan plumbing first—fixture placement determines everything else.
🔑 Key Takeaways
- Fixture replacement: $500-$1,500 when fixtures stay in same location
- Moving fixtures: $2,500-$5,000 for new drain/water line routing
- Complete rough-in: $5,000-$8,000 for gut renovations
- Permits required: For any drain/vent/water line modifications
- Timeline: 1-5 days for plumbing rough-in, plus inspection wait
Understanding Bathroom Plumbing Scope
Bathroom renovation plumbing falls into three categories with dramatically different costs and timelines:
1. Like-for-Like Fixture Replacement
Replacing fixtures in their current locations: new toilet on existing flange, new vanity with same drain position, new tub/shower in same footprint. This is the simplest and least expensive option.
Cost: $500-$1,500 | Timeline: 1 day | Permit: Usually not required
2. Reconfigured Layout
Moving fixtures to new positions within the existing bathroom. This requires new drain runs, water supply extensions, and potentially vent modifications. Opens floors, walls, and sometimes ceilings.
Cost: $2,500-$5,000 | Timeline: 2-4 days | Permit: Required
3. Complete Rough-In (Gut Renovation)
Demolition to studs with all new plumbing—common in older Toronto homes (pre-1970) where existing pipes are galvanized steel or outdated layouts need complete redesign.
Cost: $5,000-$8,000 | Timeline: 3-5 days | Permit: Required
Bathroom Plumbing Costs Breakdown
| Work Type | Labor | Materials | Total |
|---|---|---|---|
| Toilet replacement (same location) | $150-$250 | Varies | $150-$250 + toilet |
| Vanity/sink replacement | $200-$400 | $50-$150 | $250-$550 + vanity |
| Tub-to-shower conversion | $1,500-$3,000 | $500-$1,000 | $2,000-$4,000 |
| Move toilet 3+ feet | $1,200-$3,000 | $300-$600 | $1,500-$3,600 |
| Add second sink | $600-$1,200 | $200-$400 | $800-$1,600 |
| Shower body spray system | $800-$1,500 | $300-$800 | $1,100-$2,300 |
| Heated floor (hydronic) | $1,500-$3,000 | $500-$1,000 | $2,000-$4,000 |
| Complete rough-in (3-piece bath) | $3,500-$6,000 | $1,000-$2,000 | $4,500-$8,000 |
Materials include: copper or PEX water lines, ABS drain piping, fittings, valves, venting, hangers, and consumables. Fixture costs (toilet, vanity, tub) are additional.
Rough-In Plumbing: What's Involved
Rough-in is the stage where pipes are installed inside walls and floors before drywall goes up. This is when all the critical decisions are made.
Drain Rough-In
The drain system is the most critical—and least flexible—component. Drains must slope properly (1/4" per foot minimum) and connect to the main stack.
- Toilet: 3" or 4" drain centered 12" from finished wall (standard rough-in)
- Sink/vanity: 1-1/2" drain, typically 18-21" high in wall
- Shower: 2" drain centered in shower footprint
- Tub: 1-1/2" drain with overflow, access panel for trap
Water Supply Rough-In
Hot and cold lines are run to each fixture location. PEX is now standard for residential—faster to install and more freeze-resistant than copper.
- Toilet: Cold water only, 6" left of center, 6" above floor
- Sink: Hot and cold, typically 21" above floor, 4" apart
- Shower: Mixed hot/cold to valve, typically 48" above floor
- Tub: Hot and cold to valve, 28" above floor (deck mount varies)
Vent System
Every drain must be vented—this is non-negotiable per Ontario Building Code. Vents prevent siphoning of trap seals and allow proper drainage flow.
- Each fixture needs a vent within specified distance of trap
- Vents rise vertically and connect to main vent stack
- Air admittance valves (AAVs) allowed in some situations per OBC
- Improper venting causes gurgling, slow drains, and sewer odors
💡 Pro Tip: Plan Before Demolition
Have your plumber visit before any demo work. They can identify challenges (cast iron stack, limited ceiling height, joist direction) that affect layout possibilities. Moving a toilet 2 feet might be simple or complex depending on what's below.
Permits and Inspections
When Permits Are Required
City of Toronto requires plumbing permits for:
- Moving any drain or water lines to new locations
- Adding new fixtures (new bathroom, second sink)
- Changing pipe sizes
- Altering vent system
- New water heater installation
Not typically required: Like-for-like fixture replacement in same location (new toilet on existing flange, new faucet on existing lines).
Permit Costs
Toronto plumbing permits cost approximately $100-$400 depending on scope. Your licensed plumber can pull the permit (required in Ontario—only licensed plumbers can do permitted work).
Inspection Process
- Rough-in inspection: After pipes installed but before walls closed. Inspector checks slopes, connections, venting.
- Final inspection: After fixtures connected and everything operational.
Book inspections early—wait times in Toronto can be 1-5 business days. Don't close walls until rough-in passes.
⚠️ Why Permits Matter
Unpermitted plumbing work can: void your home insurance, require tear-out when selling (home inspectors catch it), result in fines, and create liability if flooding or leaks occur. Always use a licensed plumber who pulls proper permits.
Fixture Placement Considerations
Toilet Placement
The toilet is the hardest fixture to move because of its large drain (3-4") and direct connection to the main stack. Considerations:
- Minimum clearances: 15" from center to side wall, 18" in front (21" recommended)
- Rough-in distance: Most toilets are 12" from wall to flange center; verify before buying
- Drain slope: Must maintain 1/4" per foot to stack—distance limited by floor joist depth
- Venting: Must be within 6' of toilet trap
Shower/Tub Placement
Showers and tubs are somewhat flexible—the 2" drain is easier to route than a toilet.
- Drain access: Need access from below or through floor for trap
- Curb height: Minimum 2" dam for curbed showers per OBC
- Curbless/linear drains: Require floor slope (1/4" per foot to drain)
- Shower valve: Pressure-balanced or thermostatic required per code
Vanity/Sink Placement
Most flexible fixture—drain and supply are small and easy to route.
- Double sinks: Can share one drain with proper Y-fitting
- Wall-mount sinks: Require blocking in wall for support
- Vessel sinks: Need tall drain pop-up (ensure countertop height works)
Common Renovation Plumbing Challenges
1. Old Pipes
Toronto homes built before 1970 often have galvanized steel water lines and cast iron drains. Connecting new work to old pipes requires:
- Transition fittings (fernco couplings, dielectric unions)
- Assessment of remaining pipe life—often makes sense to replace while walls are open
- Lead service line awareness (some pre-1955 homes)
2. Joist Direction
Floor joists run one direction—large drains (3-4" toilet) running perpendicular require cutting joists (structurally significant) or furring up the floor (loses headroom). Always check before finalizing layout.
3. Limited Stack Access
The main stack (vertical drain/vent pipe) is the backbone of your plumbing. Moving a bathroom far from the stack requires long drain runs that may not maintain proper slope—or need a new stack installed.
4. Basement Bathrooms
Below-grade bathrooms require a sewage ejector pump (macerating toilet or traditional ejector pit) to lift waste to the main drain. Budget $2,000-$4,000 extra for this system.
💡 Space-Saving Tips
Wall-hung toilets save 10-12 inches of floor space (carrier hidden in wall). Corner sinks maximize small bathrooms. Linear shower drains allow wider glass panels. Consider pocket doors to maximize bathroom footprint.
Working With Your Plumber
When to Schedule
- Planning phase: Consult before finalizing design
- Demo day: Plumber caps/disconnects existing lines
- Rough-in: After framing, before insulation/drywall
- Final connection: After tiles, vanity, shower installed
What to Tell Your Plumber
- Final fixture selections (or at least specifications)
- Vanity dimensions and sink type
- Shower/tub model and drain location
- Any special features (body sprays, steam shower, heated floors)
- Tile thickness if affects drain height
Coordination With Other Trades
Plumbing rough-in must coordinate with:
- Electrician: GFI outlets, exhaust fan, heated floor
- HVAC: Heating registers, exhaust ducting
- Framer: Blocking for fixtures, joist notching
- Tiler: Drain locations, shower pan installation
Planning a Bathroom Renovation?
Get a detailed quote for your bathroom plumbing work. Our licensed plumbers serve Toronto and the GTA with expert renovation support—from planning to final connection.
Call (647) 554-4356Frequently Asked Questions
How much does bathroom plumbing cost in a renovation?
Bathroom renovation plumbing in Toronto costs $2,000-$8,000 depending on scope. Simple fixture replacements: $500-$1,500. Moving fixtures to new locations: $2,500-$5,000. Complete gut with new rough-in: $5,000-$8,000+. Adding a new bathroom: $8,000-$15,000 for plumbing alone.
Do I need a permit for bathroom renovation plumbing?
Yes, Toronto requires plumbing permits for moving drain/water lines, adding new fixtures, changing pipe sizes, or altering venting. Like-for-like fixture replacement (same location) typically doesn't require a permit. Permits cost $100-$400 and include inspections.
Can I move my toilet during a bathroom renovation?
Yes, but moving a toilet adds $1,500-$4,000 due to the 3-4 inch drain line and venting requirements. Moving more than 2-3 feet typically requires opening floors and possibly ceilings below. The new location must maintain proper slope and connect to the main stack.
How long does bathroom plumbing rough-in take?
Rough-in plumbing takes 1-3 days depending on complexity. Simple fixture replacements: 1 day. Moving fixtures to new locations: 2-3 days. Complete new bathroom: 3-5 days for rough-in alone. Inspections add 1-3 days of waiting.
Should I replace old pipes during renovation?
If your home has galvanized steel pipes (pre-1970), strongly consider replacing them while walls are open. They'll fail eventually and access is expensive. Budget $2,000-$4,000 extra for bathroom-area repiping. Cast iron drains in good condition can remain.
Can I add a bathroom to my basement?
Yes, but basement bathrooms require a sewage ejector pump ($2,000-$4,000 installed) to lift waste above the main drain. Options include a traditional ejector pit or an upflush/macerating toilet system. Both are code-compliant in Toronto.