Second Edition
Applicable to the 2024 OBC (O. Reg. 163/24) – In Effect January 1, 2025
Overview
Les Guide to Mid-Rise Wood Construction in the Ontario Building Code (Second Edition) provides a technical overview of the provisions permitting 5- and 6-storey combustible (wood) construction under the 2024 Ontario Building Code.
Developed by WoodWorks Ontario / the Canadian Wood Council, this updated edition reflects O. Reg. 163/24 and recent amendments affecting mid-rise residential (Group C) and office (Group D) buildings.
The Guide identifies key requirements, conditions, and limitations associated with mid-rise wood construction and is intended to support architects, engineers, builders, regulators, and code professionals working in Ontario.
What’s Included
This technical reference outlines:
- Height and building area limits for 5- and 6-storey wood buildings
- Fire-resistance requirements for floors, roofs, mezzanines, and loadbearing assemblies
- Sprinkler system requirements (NFPA 13 vs. 13R)
- Combustible cladding limitations and compliance pathways
- Fire blocking and concealed space requirements
- Fire department access and street-facing provisions
- Emergency power enhancements
- Structural and seismic design considerations
- Mixed-use building permissions and occupancy separation requirements
The Guide focuses on new construction and is intended to be used in conjunction with the Ontario Building Code.


