Do I need a permit to change my dryer vent routing in a Toronto home?

In most cases, rerouting a dryer vent in a Toronto home does not require a building permit, but there are important exceptions and best practices you should follow to ensure the installation is safe and code-compliant. A straightforward dryer vent reroute — changing the path of the existing vent duct from one exterior wall to another, or adjusting the routing through a basement or crawlspace — is generally considered routine maintenance or a minor alteration that does not trigger a permit requirement under the Ontario Building Code.

However, there are situations where a permit may be required. If the dryer vent reroute involves penetrating a fire-rated assembly — for example, running the vent through a fire separation wall between units in a semi-detached home or townhouse — that penetration must be properly fire-stopped and may require a building permit and inspection. If the reroute involves any electrical work, such as moving the dryer outlet or installing a booster fan, an ESA-Licensed Electrical Contractor must perform the electrical portion and obtain the necessary ESA permits. In a condo building, even a simple dryer vent reroute typically requires condo board approval because it may affect common elements or the building envelope.

Ontario Building Code requirements for dryer vents apply regardless of whether a permit is needed. The vent must be rigid or semi-rigid aluminum duct — never flexible vinyl or foil accordion-style duct, which are fire hazards and do not meet code. The maximum recommended vent run is approximately 25 feet equivalent length (each 90-degree elbow adds approximately 5 feet of equivalent length). The vent must terminate at the exterior of the building with a proper vent cap that has a damper to prevent backdrafts, pest entry, and cold air infiltration. The vent must not terminate inside the home, in the attic, in a crawlspace, in a garage, or into a soffit.

Dryer vent fires are a real and common hazard — lint buildup in dryer vents is one of the leading causes of residential fires in Ontario. When rerouting a dryer vent, keep the run as short and straight as possible, minimize elbows, and ensure all joints are fastened with foil tape (not screws, which catch lint) and run in the direction of airflow. If your reroute results in a longer vent run, consider installing a dryer vent booster fan to maintain adequate airflow — these cost $150 to $400 installed and are essential for runs exceeding 25 feet equivalent length.

GTA-specific considerations: In older Toronto homes with stone or brick foundations, routing a dryer vent to an exterior wall may require core drilling through masonry — budget $100 to $250 for a professional core drill. In newer GTA homes, the dryer is often on the second floor, requiring a longer vent run down through walls to an exterior exit point. These longer runs accumulate lint faster and need more frequent cleaning — annual dryer vent cleaning ($100 to $200) is essential for any vent run over 10 feet. A typical dryer vent reroute in a GTA home costs $300 to $800 depending on the length of the new run, the number of elbows, and whether masonry penetration is needed.