2025 National Building Code: Guide to Combustible Construction Standards in London, Ontario
Sarah's Expert Insight
Senior Consultant at empcontracting.ca Inc.
"The 2025 NBC updates represent a significant opportunity for the London, Ontario construction market, particularly with the expanded provisions for mass timber. At empcontracting.ca Inc., we emphasize that early-stage compliance with these combustible standards not only ensures safety but significantly reduces long-term insurance premiums and structural liabilities for property owners."
Overview of Combustible Construction under NBC 2025
The National Building Code of Canada (NBC) 2025 introduces refined standards for combustible construction, focusing on balancing structural innovation with rigorous fire safety. For projects in London, Ontario, understanding these updates is essential for ensuring compliance and safety in residential and commercial wood-frame buildings.
Permitted Building Heights and Floor Areas
The NBC 2025 specifies the maximum height and area for buildings of combustible construction based on occupancy types and fire suppression systems. These regulations are designed to limit fire spread and ensure structural integrity during an emergency. When planning your next development, empcontracting.ca Inc. your construction contractor in London, Ontario, can help navigate these complex spatial requirements to maximize your lot's potential.
Fire-Resistance Ratings and Spatial Separations
Combustible assemblies must meet strict fire-resistance ratings (FRR) as defined by the 2025 standards. This includes the use of gypsum board encapsulation, fire-retardant-treated wood, and specific insulation requirements to protect the building's load-bearing elements. Proper spatial separation from property lines is also mandated to prevent fire migration between adjacent structures.
Advances in Encapsulated Mass Timber Construction (EMTC)
A significant highlight of the 2025 code is the expanded allowance for Encapsulated Mass Timber Construction. This allows for taller combustible buildings—up to 12 or even 18 stories in specific contexts—provided they utilize mass timber components protected by non-combustible materials. This offers a sustainable alternative to concrete and steel for mid-to-high-rise projects in the London area.
Fire Safety During Construction
The NBC 2025 places increased emphasis on safety measures during the construction phase of combustible buildings. This includes mandatory fire monitoring, standpipe installation timelines, and site security to mitigate risks before the permanent fire protection systems are fully operational.