The Ontario Building Code | Clearance to Buildings
3.1.19.1. Clearance to buildings
(1) A building shall not be located beneath existing above ground electrical conductors.
(2) The horizontal clearance measured from the maximum conductor swing to the building, including balconies, fire escapes, flat roofs or other accessible projections beyond the face of the building, shall,
(a) be not less than 1 m, for electrical conductors carrying voltages 750 V or less, except where necessary to connect to the electrical wiring of the building,
(b) be not less than 3 m, for electrical conductors carrying voltages greater than 750 V but not exceeding 46 kV,
(c) be not less than 3.7 m, for electrical conductors carrying voltages greater than 46 kV but not exceeding 69 kV, or
(d) conform to the requirements of CAN/CSA-C22.3 No.1, "Overhead Systems", for electrical conductors carrying voltages greater than 69 kV.
(3) Where the swing of an above ground electrical conductor not owned or operated by an electrical supply authority is not known, a swing of not less than 1.8 m shall be used.
(4) Sentences (1) to (3) do not apply to a buildingcontaining electrical equipment and electrical installations used exclusively in the generation, transformation or transmission of electrical power or energy intended for sale or distribution to the public.
3.1.20. Glass in Guards
In Plain Language
Buildings cannot be located directly beneath existing above-ground electrical conductors, and minimum horizontal clearance from the conductor's swing to the building (including balconies and similar projections) scales up with the conductor's voltage, from 1 m for low-voltage lines up to much larger clearances for high-voltage transmission lines.
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.