What is the fire separation requirement between a basement suite and attached garage?

In Ottawa, you need a minimum 45-minute fire-rated separation between a basement suite and any attached garage, as required by the Ontario Building Code.

This fire separation requirement is critical for secondary dwelling units and applies to all walls, floors, and ceilings that separate the living space from the garage. The 45-minute fire rating means the assembly must prevent fire from spreading for at least 45 minutes, giving occupants time to evacuate safely.

Typical fire separation assemblies include 5/8" Type X drywall on both sides of the wall with proper sealing, or concrete block construction. All penetrations through the fire separation (pipes, ducts, electrical) must be properly sealed with fire-rated materials. The door between the garage and suite must be a solid core door with self-closing hinges and proper weatherstripping to maintain the fire barrier.

Ottawa's secondary suite requirements are particularly strict about garage separation because carbon monoxide from vehicles poses an additional hazard beyond fire risk. The City of Ottawa Building Code Services requires detailed drawings showing the fire separation details as part of your permit application. Many homeowners underestimate this requirement when planning basement suite conversions, but it's non-negotiable for permit approval.

Professional installation is essential for fire-rated assemblies because improper installation voids the fire rating entirely. Common mistakes include using regular drywall instead of Type X, inadequate sealing around penetrations, or missing fire-rated door hardware. The building inspector will specifically check these details during the framing and drywall inspections.

If you're planning a basement suite conversion with an attached garage, factor this fire separation work into your budget early. The materials and labor for proper fire-rated construction typically add $2,000-4,000 to the project cost, but it's required by code and essential for safety. For a free consultation on your basement suite project and proper fire separation planning, contact Ottawa Basements - we ensure all secondary dwelling units meet Ontario Building Code requirements from day one.