2024 Ontario Building Code: Exit Widths and Headroom for Group B Occupancies
Sarah's Expert Insight
OBC Compliance Specialist
"In high-growth areas like London and Oakville, adhering to the 1,650 mm corridor width for Group B facilities is a frequent pain point in medical office conversions. As a senior consultant at empcontracting.ca Inc., I emphasize that these dimensions are critical for stretcher and mobility aid clearance, and failing to account for the 2,100 mm headroom in Muskoka-based historical retrofits can lead to immediate permit failures."
When navigating the complexities of the 2024 Ontario Building Code (OBC), specifically for Care and Treatment facilities, precision is vital. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure your projects meet these rigorous safety standards for Group B occupancies.
Minimum Widths for Exit Corridors and Doorways
Table 3.4.3.2.-B specifies the mandatory widths for facilities categorized under Group B, Division 2 and Division 3. If a corridor or doorway is serving patients' or residents' sleeping rooms, the requirements are significantly higher to facilitate emergency movement:
- Exit Corridors: 1,100 mm (not serving sleeping rooms) vs. 1,650 mm (serving sleeping rooms).
- Doorways: 850 mm (not serving sleeping rooms) vs. 1,050 mm (serving sleeping rooms).
- Stairs: Minimums range from 900 mm to 1,100 mm depending on the number of storeys served.
Regulations on Exit Width Reductions
Section 3.4.3.3 mandates that no construction or fixtures may obstruct the required exit width, with a few critical exceptions for functional components:
- Door Swings: Must not reduce exit stair or landing width to less than 750 mm.
- Handrails: Projections of up to 100 mm on each side are permitted.
- School Safety: In elementary or secondary schools, intermediate handrails are required when stair lifts are installed to maintain the path of travel.
Headroom Clearance Requirements
Maintaining adequate vertical clearance is a primary safety concern under Section 3.4.3.4 of the OBC:
- General Exits: A minimum clear height of 2,100 mm is required.
- Stairways: Must maintain at least 2,050 mm of vertical clearance measured from the tread nosing.
- Doorways: Generally require a minimum clear height of 2,030 mm.
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.