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New-House Plumbing in Ontario (2026): What It Costs per Fixture, Plumbing an ICF House, Bathroom Rough-Ins, PEX or Copper, Water Pressure and Cottage Plumbing
Plumbing & WaterNew-house plumbing
New-House Plumbing: Count the Fixtures, Then Count Them Again
Cost per fixture, ICF walls and slabs, bathroom rough-ins, pipe choices, pressure and cottages. Ontario, October 2026.
Plumbing is priced by the fixture, so the cheapest plumbing decision you will ever make is the one you make with a pencil on the floor plan. Every toilet, sink, tub, shower, laundry tap and hose bib is a line on the quote, and every one added after the slab or the drywall costs far more.
The numbers
$1,000rough-in per fixture, new house ($800 to $1,200)
$300trim per fixture, labour only ($250 to $350)
$15,60012 fixtures rough and trim at the defaults, our estimate
$150 to $400core drill allowance for a forgotten sleeve in ICF
What a plumbing quote counts, and what it leaves out
A new-house plumbing quote is usually rough-in per fixture plus trim per fixture. Rough-in is the pipe in the walls and floors before they close; trim is setting the toilets, taps and sinks after the finishes. A Halton/Hamilton plumber put the whole-house rough-in for a standard house with several bathrooms and a kitchen at $8,000 to $15,000 or more, and that is the rough-in alone.
What the per-fixture number usually leaves out: the water heater, the fixtures themselves (call them an allowance and write it down), the underground under the slab, the water service from the street or the well line from the pressure tank, and the permit. What plumbing a new house costs goes through it line by line, the plumbing cost estimator does the arithmetic, and plumbing in a new Ontario house explains how it all gets built.
ICF walls and radiant slabs: the pour is the deadline
On the ICF houses we build the exterior walls are foam forms filled with concrete. The water service or well line, the sewer or septic outlet, the hose bibs, the dryer vent, the boiler or water heater vent and the radon or sump discharge all pass through that concrete, and each needs a sleeve set in the form before the pour. Interior walls are ordinary frame and get plumbed the ordinary way. Keeping supply pipes out of exterior walls where you can is the usual rule in any Ontario house, ICF or not.
The radiant tubing in our basement slabs is tied down before the pour, so every drain, the sump pit and any future bathroom rough-in has to be placed, inspected and protected first. Plumbing an ICF house has the penetration list, and ICFPro.ca covers the walls and foundations themselves.
Showers, pressure and the pipe in the walls
Every shower and bathtub in a new Ontario house needs an automatic compensating valve, pressure-balanced or thermostatic, under Article 7.2.10.7 of the code, and the code caps the outlet temperature at 49 C. That is the valve that keeps you from being scalded when someone flushes downstairs. If the shower still drops off, the cause is usually upstream: the pressure tank and switch on a well, a clogged sediment filter, or old galvanized pipe. Water pressure problems sorts them out.
As for the pipe, PEX runs about $1.50 to $4.00 a foot and copper $4.00 to $12.00, supply only; nobody we found publishes an installed whole-house difference. PEX or copper covers the rest.
The guides
What plumbing a new house costs
Rough-in and trim per fixture, a 12-fixture house worked out, what a plumbing quote includes and quietly leaves out, municipal water against a well and septic, and the stage payments.
Plumbing an ICF house
Sleeves before the pour and the penetration list, under-slab drains and radiant tubing before the slab, the sump pit, a future basement bathroom, and what a forgotten sleeve costs.
Bathroom rough-in cost
Adding a bathroom to an existing house or basement: rough-in stubs against breaking the slab, gravity against an ejector or an upflush toilet, venting, the permit, and three cases priced.
PEX or copper?
PEX, copper and CPVC in an Ontario house: material per foot, home-run manifold against trunk and branch, fittings, freezing, noise, sunlight, rodents, and what inspectors and insurers think.
Water pressure problems
Low pressure, a shower that drops off, banging pipes: town water against a well, the pressure tank and switch, clogged filters, galvanized pipe, pressure-reducing valves and what each fix costs.
Opening and closing a cottage
Draining the system, the pump and tank, the water heater, traps and RV antifreeze (never automotive), heat cable, the lake line, the spring water test and frozen pipe repairs.
Plumbing in a new Ontario house
Already on the site: when the plumbing happens in the build, the supply side, drains, waste and vents, and what the inspector checks.
Plumbing cost estimator
Already on the site: the new-construction plumbing arithmetic per fixture and per square foot, municipal against well and septic, basement against slab.
Curbless shower cost
Already on the site: what a curbless shower costs, and why the floor has to be planned before the tile goes down.
Shower waterproofing
Already on the site: the membrane under the tile and where showers fail.
Bathroom design checklist
Already on the site: the layout and fixture decisions to make before the plumber roughs anything in.
The calculators
Free, on the same October 2026 prices these pages use. A budget and a better question, not a quote.
Plumbing cost estimator
Already on the site: new-construction plumbing per fixture and per square foot, municipal against well and septic, basement against slab.
Rural water system cost calculator
The well, the pump and tank, the trench and line to the house, the test and the treatment, for a new house with no town water.
Water heater rent or buy calculator
The water heater the plumbing quote probably left out: rent against buying a tank, heat pump or tankless.
Tile shower cost calculator
Already on the site: what the shower costs once the plumber has roughed in the valve and the drain.
What it costs, October 2026
| Item | Ontario range, installed | Notes |
|---|---|---|
| Rough-in per fixture, new construction | $800 to $1,200 | an Ottawa plumber about $950; a Halton plumber up to $1,800; $1,000 default |
| Trim, setting fixtures, labour per fixture | $250 to $350 | $300 default; fixtures are extra |
| Whole-house rough-in, several baths and a kitchen | $8,000 to $15,000 or more | a Halton/Hamilton plumber, rough-in alone |
| 12-fixture house, rough-in plus trim | $12,600 to $18,600 | our estimate, before water heater, permit, underground and fixtures |
| Renovation rough-in per fixture | $1,200 to $1,800 | condo $1,400 to $2,000 |
| Basement 3-piece rough-in, existing stubs | $3,000 to $6,000 | $4,500 default |
| No stubs: break and patch the slab | add $1,500 to $8,000 | $4,000 default |
| Sewage ejector for drains below the sewer | add $1,500 to $3,500 | battery backup $300 to $600 |
| Pipe, supply only, per linear foot | PEX $1.50 to $4.00; copper $4.00 to $12.00 | no installed whole-house difference published |
| Toronto basic plumbing permit | $205 up to 5 fixtures | plus $16 each beyond 5; check your municipality |
Worked example, 12 fixtures at the defaults: 12 x $1,000 = $12,000 rough-in plus 12 x $300 = $3,600 trim is $15,600, our estimate; add a Toronto permit at $205 + 7 x $16 = $317 and it is $15,917 before HST, still before the water heater, the underground, the service and the fixtures. Other municipalities price permits differently.
Why Ontario prices are all over the map: the contractors and published price guides we checked for this page quoted very different prices for the same house. A Toronto plumber published $800 to $1,200 a fixture for rough-in, an Ottawa plumber about $950, and a Halton plumber $800 to $1,800. On 12 fixtures that is $9,600 to $21,600 for the rough-in alone, and the whole-house figure from the Halton plumber was $8,000 to $15,000 or more. Trim, the fixtures, the water service and the water heater are in some quotes and not in others. Budget $1,300 a fixture for rough-in and trim plus a fixture allowance, and get two or three quotes on the same written scope.
Rules of thumb worth keeping
- Count the fixtures on the plan before anyone quotes. Hose bibs, the laundry tub, the fridge line and the basement rough-in count too. The bathroom design checklist.
- Rough in the basement bathroom now even if you finish it in ten years. Stubs in an open floor are cheap; breaking a slab later adds $1,500 to $8,000.
- In ICF, list every penetration before the pour. Then check the list again with the forms standing and the plumber beside you.
- Nothing under the slab gets covered before the inspector sees it. On a radiant slab, that includes the tubing over the top of it.
- Write the fixtures down as an allowance in dollars. “Fixtures by owner” and “fixtures included” are two different numbers wearing the same total.
Have quotes in hand? Let a builder read them first
For $99 I read up to three plumbing, well or water treatment quotes, or one quote plus your water test report, and put them on one grid: fixtures, rough-in and trim, the water heater, the underground and service or well line, the pump and tank, the treatment and its order, the permit and the warranty. You get a written answer on what each one left out, in dollars, and which one I would sign.
There is no contractor network behind it and no referral fee on who you hire. We are a builder, not a plumbing contractor or a well contractor: on our own builds and renovations in Simcoe, Muskoka and Georgian Bay the plumbing is done by licensed plumbers we hire and the wells are drilled by licensed well contractors. Outside that area I will tell you honestly whether I know anyone.
Questions people ask
How much does plumbing a new house cost in Ontario?
About $800 to $1,200 a fixture for rough-in and $250 to $350 a fixture for trim labour. A 12-fixture house is about $12,600 to $18,600 by our estimate, before the water heater, the permit, the underground and service, and the fixtures. What plumbing costs works it through.
What does it cost to add a basement bathroom?
A 3-piece rough-in runs about $3,000 to $6,000 with existing stubs. With no stubs, breaking and patching the slab adds $1,500 to $8,000, and an ejector for drains below the sewer adds $1,500 to $3,500. Bathroom rough-in cost prices three cases.
Is PEX allowed in Ontario houses?
Yes, PEX is widely used in Ontario houses alongside copper. The choice is about fittings, layout, noise and where the pipe runs, not legality. PEX or copper covers what inspectors and insurers think.
How hot can the shower be?
The code caps the outlet temperature at showers and bathtubs at 49 C, and requires an automatic compensating valve, pressure-balanced or thermostatic, on each. If your shower scalds when someone flushes, the valve is the first suspect.
What antifreeze goes in cottage traps?
RV (non-toxic) antifreeze, never automotive. The traps and toilets drain to the septic system. Opening and closing a cottage has the rest of the fall list.
Price the plumbing before the walkthrough
The plumbing cost estimator takes your fixture count, municipal or well and septic, and basement or slab, and gives a budget to hold the quotes against. If you have quotes already, send up to three to the $99 review.
Sources and further reading
- The 2024 Ontario Building Code: Ontario on the 2024 Code: in force January 1, 2025, the grace period to March 31, 2025, and the harmonization with the national codes.
- Toronto standalone plumbing and drain permits: what a plumbing permit covers in Toronto and the published fees.
- ICFPro.ca: ICF walls and foundations, including the sleeves and penetrations planned before the pour.
