Which Plumbing Code Does Ontario Use?

Where plumbing sits in the Ontario Building Code

The OBC is split into Divisions. Division B holds the technical requirements, and plumbing is Part 7 of Division B. Part 8 covers on-site sewage systems such as septic systems.

Part 7 is organized into sections: 7.1 General, 7.2 Materials and Equipment, 7.3 Piping, 7.4 Drainage Systems, 7.5 Venting Systems, 7.6 Potable Water Systems and 7.7 Non-Potable Water Systems.

Is it the same as the National Plumbing Code?

No. The National Plumbing Code of Canada is a model code. Provinces decide whether and how to adopt it. Ontario writes its own Building Code, which is closely aligned with the national model codes but has its own wording and Ontario-specific requirements.

For Ontario work and Ontario exam prep, the Ontario Building Code is the document that governs. Don't assume a rule from another province's code or the national model code applies here.

Which edition applies?

Ontario updates the Building Code periodically, with a newer edition replacing the 2012 Building Code. The edition that applies to a job depends on when the permit was applied for, so always check the current edition and its transition rules on the Government of Ontario website.

For the exam, study the edition your exam is based on. If you're unsure, ask Skilled Trades Ontario or your training delivery agent.

Where to get the code

The Ontario Building Code regulation can be read for free on Ontario's e-Laws website. Printed and annotated versions, which many apprentices prefer for studying, are sold by commercial publishers.