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The Ontario Building Code for Residential Bathrooms

If you are planning a bathroom renovation in Ontario, it is important to be aware of the Ontario Building Code requirements. In this blog post, we will provide an overview of the code and discuss some of the most important aspects that you need to know.

Sections 3, 6, and 9 of division B are related to bathroom construction in residential settings. Starting with some basics and fulfilled naturally without much attention.

Basic: states every home should have a fully functional bathroom that includes a vanity, tub/shower, and toilet. If an architect made mistake and designs a home without a bathroom, it will get rejected when applying for permits.

Fire safety: states all plumbing fixtures, wall, and ceiling should have a flame-spread rating not more than 200. This is a non-issue for almost all bathrooms, a standard drywall flame spread rating is less than 100, most wood paneling is below between 100-200, and stainless steel is 0.

Accessibility: states a door is mandatory for a bathroom that contains a toilet. This ensures the privacy of the user. states the minimal door size to a bathroom is 24″ width and 78″ high. We recommend a 36″ door if you need wheelchair accessibility. Has several amendement made since 2015 that discuss the need for grab bars. A grab bar must be installed in shower, tub and toilet. discuss the need for safety glass. Only safety glass can be used for shower or bathtub enclosure. There is a very tiny risk of glass exploding, if that happens, then temper glass is much safer to use.

Venting: states an exhaust fan is required in the bathroom. The length of the ductwork can not exceed 9m and the number of elbows need to be less than 4.


Bathroom renovation must comply with all standard plumbing requirement. ie: S trap can not be used. Vent must be connect above flood rim etc. states toilet must be provided with a shut-off valve

Table discuss the minimal supply pipe size. 1/2″ is perfect for all except for Water closet, with direct flush valve discuss the maximum flow allowed


Bathroom must comply with all standard electrical code and product manuals.

A Class A (5 mA) ground fault circuit interrupter (GFCI) is required for each circuit for heated floor.

A heating device installed less than 1.8 m above the floor shall not be installed less than 1 m horizontally from a sink (wash basin complete with
drainpipe), tub or shower stall, this distance being measured horizontally between the heating device and the sink, tub or shower stall unless it is
protected by a GFCI.

A GFCI shall be installed no closer than 3 m from the water’s edge.

Use 14 AWG copper wire for general purpose wiring (lights and receptacles).

Install a maximum of 12 outlets on a general purpose circuit (lights and receptacles).

GFCI should be installed near the sink and at least one GFCI protected outlet is required.

Pot lights in shower should be IC and damp rated.

Receptacles shall not be located within 1.5 m of the pool or hot tub
• Receptacles located between 1.5 m and 3 m shall be GFCI protected.

As you can see, there are many important aspects to consider when renovating a bathroom in Ontario. If you have any questions, feel free to reach out to us for assistance.