The 2024 OBC significantly expands the permissions for "mass timber" construction. Following global trends and extensive fire safety testing, the code permits encapsulated mass timber construction (EMTC) for buildings up to 12 storeys (previously limited to 6 under specific conditions, or 18 storeys under an alternate compliance path in the 2022 amendments).
This shift is strategic for two reasons:
The code introduces strict fire safety provisions for these structures, including encapsulation requirements and redundant fire suppression systems, addressing public safety concerns while unlocking new architectural possibilities.
The Supplementary Standard SB-12 has been overhauled. For residential homes (Part 9 buildings), prescriptive thermal resistance (R-value) requirements have increased:
The Game Changer: Airtightness Testing
New Part 9 residential construction must now undergo blower door testing, achieving ≤ 2.5 Air Changes per Hour (ACH) at 50 Pascals. This is a major step toward Passive House standards.
The notorious "plumbing vent through the roof" rule remains, but new allowances for Air Admittance Valves (AAVs) (Studor valves) have been expanded for island sinks and remote fixtures, provided they meet the new standard CAN/CSA-B79.
To reduce falls, the 2024 amendments change residential stair dimensions:
Ontario Building Code — 2024
The 2024 OBC significantly expands the permissions for "mass timber" construction. Following global trends and extensive fire safety testing, the code permits encapsulated mass timber construction (EMTC) for buildings up to 12 storeys (previously limited to 6 under specific conditions, or 18 storeys under an alternate compliance path in the 2022 amendments).
The code introduces strict fire safety provisions for these structures, including encapsulation requirements and redundant fire suppression systems, addressing public safety concerns while unlocking new architectural possibilities. The 2024 OBC significantly expands the permissions for
The Supplementary Standard SB-12 has been overhauled. For residential homes (Part 9 buildings), prescriptive thermal resistance (R-value) requirements have increased: The code introduces strict fire safety provisions for
The Game Changer: Airtightness Testing
New Part 9 residential construction must now undergo blower door testing, achieving ≤ 2.5 Air Changes per Hour (ACH) at 50 Pascals. This is a major step toward Passive House standards.
The notorious "plumbing vent through the roof" rule remains, but new allowances for Air Admittance Valves (AAVs) (Studor valves) have been expanded for island sinks and remote fixtures, provided they meet the new standard CAN/CSA-B79.
To reduce falls, the 2024 amendments change residential stair dimensions: