Ontario Building Code 3.3.1.5: Egress Doorway Requirements and Travel Distances
Sarah's Expert Insight
OBC Compliance Specialist
"Understanding the nuances of Section 3.3.1.5 is essential for high-occupancy projects in regions like Muskoka and London, where sprinkler status directly dictates floor plan flexibility. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize these life-safety egress metrics to ensure every project remains fully compliant with the 2024 Building Code Compendium while optimizing your usable square footage."
Navigating the 2024 Building Code Compendium is essential for any safe and legal construction project in Ontario. Article 3.3.1.5. specifically outlines the requirements for egress doorways based on occupancy type, floor area, and whether a building is equipped with a sprinkler system.
When are Two Egress Doorways Required?
According to the OBC, multiple egress doorways are mandatory under several conditions to ensure occupant safety. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure your designs account for these specific triggers:
- Non-Sprinklered Areas: If the room or suite area or the travel distance to the nearest egress exceeds the values defined in Table 3.3.1.5.-A.
- Sprinklered Areas: If the travel distance exceeds 25 meters or the area exceeds values in Table 3.3.1.5.-B.
- Educational Facilities: Any hazardous classroom in an elementary or secondary school exceeding 100 m² must have two doorways.
Table 3.3.1.5.-A: Egress in Non-Sprinklered Floor Areas
For buildings without a sprinkler system, the limits are stricter. For example:
- Group A (Assembly): Max area 150 m², Max travel distance 15 m.
- Group D (Office/Business): Max area 200 m², Max travel distance 25 m.
- Group F-2 (Industrial): Max area 150 m², Max travel distance 10 m.
Table 3.3.1.5.-B: Egress in Sprinklered Floor Areas
Sprinkler systems allow for increased flexibility in floor plan design:
- Group A (Assembly): Max area increases to 200 m².
- Group D (Office/Business): Max area increases to 300 m².
- Group C (Residential): Max area 150 m² (Subject to Article 3.3.4.4).
The One-Third Diagonal Separation Rule
When two egress doorways are required, their placement is strictly regulated. They must be separated by a distance equal to or greater than one-third of the maximum overall diagonal dimension of the area served. This measurement is calculated based on the shortest distance smoke would travel between the doors, ensuring that a single fire event cannot block both exits simultaneously.
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.