Order summary
In Toronto, adding or altering drain, waste, vent or water supply piping has generally needed a building permit for plumbing from Toronto Building. Swapping a fixture on existing pipes usually has not. When in doubt, ask the City or your plumber before the work starts, not after. Rules change, so treat this leaflet as a starting point and check the City's current guidance.
Numbered steps
- Describe the job. Write down exactly what is changing: new fixtures, moved drains, a new water line, a backwater valve, a basement bathroom.
- Check whether it is a permit job. Typical permit items include new bathrooms, relocated drains, backwater valves, new water services, and sump or drain work below the floor. Swapping a fixture for a matching one, or a basic repair, typically is not.
- Decide who applies. A homeowner can apply, or the plumbing contractor can. Agree on this in writing before work begins.
- Keep the permit posted. It should be visible on site while the work is underway.
- Book inspections at the right stages. Drains under a basement floor must be inspected before the concrete goes back. Piping in walls must be inspected before drywall.
- Keep the paperwork. Save the permit, inspection results and the final sign-off with your house records.
Plumber's tip: Gas work is a separate system. Gas lines and gas appliances are installed by licensed gas technicians under Ontario's gas safety rules, regulated by the TSSA, not through a City plumbing permit.
Errors we see on site
- Closing walls or pouring concrete before inspection. The inspector may ask you to open it back up.
- Assuming the contractor pulled the permit. Ask for the permit number.
- Skipping permits to save time. Unpermitted work can surface when you sell, refinance or claim on insurance, and fixing it then usually costs more.
- Forgetting subsidy rules. Toronto's basement flooding subsidy has required a permit for work like backwater valves or sump pumps. No permit can mean no subsidy. See our subsidy leaflet.
Outside Toronto, the rules come from your own municipality. Thornhill homeowners, for example, deal with Vaughan or Markham.
An inspection is not a formality. The inspector checks slope on drains, venting, trap arms, test pressure and materials against the Ontario Building Code. That is a second set of eyes on work you will live with for decades, and the sign-off is proof later that it was done properly.
When the desk should come out
Call before the job is designed, not after the walls are open. For work like a basement bathroom rough-in or a backwater valve installation, we tell you up front whether it needs a permit, who will apply, and which inspections to expect. That goes on the work order with the price.
Renovating? Our before you finish a basement leaflet covers what to settle first. For gas work, see gas line installation.
Questions about a specific job? Call (365) 517-5705.
Quick checklist
- Ask whether the job needs a permit
- Book inspections before walls close
- Keep the permit card on file
Your questions on this one
Does swapping a toilet need a permit or faucet?
Generally not, if you are replacing it on the existing pipes without changing the drain or supply layout.
Can I apply for a plumbing permit myself?
Homeowners can apply for work on their own house. Many prefer to have the contractor do it, since they know the drawings and inspection stages.