Ontario Building Code Guidelines for Multi-Storey & Group D Buildings | empcontracting.ca Inc.
Sarah's Expert Insight
OBC Compliance Specialist
"As a senior consultant at empcontracting.ca Inc., your construction contractor in London, Ontario, I find that the 6-storey combustible construction provisions are a major benefit for developers in London and Oakville seeking to increase density. However, the strict 1-hour fire-resistance ratings and occupancy height caps require meticulous planning during the design phase to avoid costly mid-project revisions in regions like Muskoka where terrain and accessibility further complicate fire response logistics."
Understanding the complexities of the 2024 Ontario Building Code (OBC) is essential for successful commercial and residential development. At empcontracting.ca Inc. your construction contractor in London, Ontario, we specialize in navigating these technical requirements to ensure your project is both compliant and optimized for safety.
Section 3.2.2.60: Requirements for Multi-Storey Buildings
This section outlines the limitations and construction requirements for buildings up to 6 storeys. Key height and area constraints include:
- Maximum Height: 18 m between the first storey and the uppermost floor.
- Building Area: Limits range from 18,000 m² for a single storey down to 3,000 m² for a 6-storey structure.
- Fire Safety: Floor and roof assemblies must maintain a fire-resistance rating of at least 1 hour.
Construction and Occupancy Restrictions
Buildings under this article allow for combustible or noncombustible construction. However, specific major occupancies like Group A (Assembly), Group E (Mercantile), and Group F (Industrial) are generally restricted to the lower storeys (below the third floor) to ensure rapid egress and fire safety. Storage garages are permitted below the fourth storey.
Section 3.2.2.61 & 3.2.2.62: Group D (Business and Personal Services)
Group D buildings, which include offices and professional services, have specific paths to compliance based on whether they are sprinklered.
Sprinklered Group D Buildings (Up to 4 Storeys)
Under Article 3.2.2.61, a Group D building is permitted to be up to 4 storeys if it is sprinklered throughout and does not exceed a building area of 3,600 m². These structures require 1-hour fire-resistance ratings for floor assemblies, mezzanines, and loadbearing supports.
Standard Group D Buildings (Up to 3 Storeys)
Article 3.2.2.62 governs Group D buildings up to 3 storeys. The allowable building area for these structures is determined by specific OBC tables, emphasizing the balance between building size and structural fire protection.
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.