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OBC DIVISION B · PART 9 · SECTION 9.31 — PLUMBING FACILITIES

What plumbing fixtures must every dwelling unit have in Ontario?

Every dwelling unit needs a kitchen sink, a water closet (toilet), a lavatory (bathroom sink), and a bathtub or shower. Provisions for laundry facilities are also required, and all fixtures must connect to approved water supply and drainage systems.

Code reference
A dwelling unit must be provided with a minimum set of sanitary fixtures: kitchen sink, water closet, lavatory and a bathtub or shower stall, together with facilities or connections for laundry. Fixtures must be served by potable water and connected to a sanitary drainage system, with the plumbing itself installed under Part 7 of the Code.
OBC Division B, Subsection 9.31.4.

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

This subsection defines what makes a space a legally complete dwelling, which matters most in basement apartment and secondary suite projects: a rec room with a bar sink is not a dwelling unit, and conversely, creating a full second kitchen and bath can trigger second-unit requirements. Laundry provisions can be shared in some multi-unit arrangements. The fixture list is the Part 9 baseline; actual pipe sizing, venting, traps and materials fall under Part 7 (Plumbing) and require a plumbing permit and inspections.

Plain language

By law, a home needs a kitchen sink, a toilet, a bathroom sink and a tub or shower, plus somewhere to do laundry. If a unit is missing any of these, it does not count as a legal dwelling.

Related questions

Which fixtures need hot and cold running water in an Ontario home?Is a floor drain required in the basement of a house in Ontario?

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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.