2024 Ontario Building Code Guide: Group A and B Construction Standards by empcontracting.ca Inc. in London, Ontario
Sarah's Expert Insight
OBC Compliance Specialist
"In high-growth regions like London and Oakville, navigating the sprinkler triggers for Group A assembly spaces is critical; a simple change in intended use for trade shows can drastically alter your fire-suppression budget. At empcontracting.ca Inc., we leverage these OBC nuances to help developers in Muskoka and beyond choose the most cost-effective fire-rated assemblies—like fire-retardant-treated wood—without compromising on safety or compliance."
Navigating the complexities of the 2024 Ontario Building Code (OBC) is essential for successful commercial and institutional developments. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that your project adheres to the specific fire-safety and material requirements outlined in Sections 3.2.2.32 through 3.2.2.36.
Group A, Division 3: Requirements for Arenas and Exhibition Spaces
Buildings classified under Group A, Division 3—such as community arenas or exhibition halls—face strict regulations regarding fire-resistance ratings. For roof assemblies using combustible construction, a minimum 45-minute fire-resistance rating is required. However, this may be waived if fire-retardant-treated wood is used and the building area remains within specific limits based on street frontage (ranging from 1,200 m² to 1,800 m²).
Sprinkler Mandates for Occasional Trade Shows
According to OBC 3.2.2.32.(3), any Group A, Division 3 building exceeding 1,500 m² intended for occasional trade shows or exhibitions must be sprinklered throughout. For single-storey structures, combustible construction is permitted up to 7,200 m² if fully sprinklered, or significantly smaller areas if unsprinklered.
Group A, Division 4: Open-Air Assembly and Stadiums
Stadiums and other Division 4 structures generally require noncombustible construction. Exceptions exist for heavy timber roof assemblies or smaller buildings with occupant loads under 1,500 and a limiting distance of at least 6 meters. Notably, any occupancy space located beneath tiers of seats must be protected by a sprinkler system to meet safety protocols.
Group B, Division 1: High-Security Care and Detention Facilities
For detention centers and high-security care facilities, the code mandates noncombustible construction regardless of height or area. These buildings must be fully sprinklered, and floor assemblies are required to serve as fire separations with a fire-resistance rating of no less than 2 hours to ensure occupant safety in restricted-egress environments.
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.