The Ontario Building Code | Service Lines under Buildings
3.2.3.21. service Lines under buildings
(1) A building shall not be constructed over an existing buried flammable gas main unless the gas main is encased in a gas-tight conduit in conformance with CAN/CSA-Z662 / Z662.1, "Oil and Gas Pipeline Systems / Commentary on CAN/CSA-Z662-11, Oil and Gas Pipeline Systems".
3.2.4. Fire Alarm and Detection Systems