The Ontario Building Code | Separate Services
7.1.5.4. Separate services
(1) Except as provided in Sentences (2) and (3), piping in any buildingshall be connected to the public services separately from piping of any other building.
(2) An ancillary building on the same property as the main building may be served by the same service.
(3) Water service pipes or building sewers serving buildings located on the same property may connect into a private water supply or a private sewer conforming to Article 7.1.5.5.
(4) No plumbing serving a dwelling unitshall be installed in or under another unit of the buildingunless the piping is located in a tunnel, pipe corridor, common basement or parking garage, so that the piping is accessible for servicing and maintenance throughout its length without encroachment on any private living space, but this Sentence does not prevent plumbing serving a unit located above another unit from being installed in or under the lower unit.
In Plain Language
Except in specific cases, piping in any building must connect to public services separately from the piping serving any other building, keeping each building's plumbing system independently traceable and maintainable.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.