Ontario CodeNews Issue 384: Amendments to Ontario's 2024 Building Code

The Ministry of Municipal Affairs and Housing has amended Ontario's 2024 Building Code to support the development of four-storey townhouses and expand the use of cellular core polyvinyl chloride (PVC) drain-waste-vent (DWV) pipe. The following changes came into effect on July 22, 2026:

Support Development of Four-Storey Townhouses

The Ministry has made changes under Part 3 of the Ontario Building Code to remove design constraints for four-storey non-stacked townhouses, allowing their construction without the need for alternative solutions, while maintaining appropriate safety standards, including:

• Automatic Sprinkler Systems: Four-storey townhouses must use NFPA 13D (domestic) sprinkler systems to support fire control and ensure adequate water supply.

• Building Size Limits: Building footprint must be limited to 600 m² or less to enable effective exterior firefighting based on hose reach and water pressure.

• Occupant Protection and Egress: Buildings must face a fire access route, with third- and fourth-storey windows sized for fire department access, along with sprinklered balconies.

Expand Use of Cellular Core Polyvinyl Chloride Drain-Waste-Vent Pipe

The Ministry has amended the Building Code to broaden the use of cellular core polyvinyl chloride (PVC) drain-waste-vent (DWV) pipe to all residential combustible buildings.

The change pertains to Division B, Article 7.2.5.16. of the Code and permits the use of cellular core PVC pipe in combustible buildings up to six-storeys. This represents an expansion of the previous provisions, which limited the use of cellular core PVC piping to residential buildings containing one or two dwelling units, as well as row houses up to three-storeys.

These changes are now included in an updated Ontario Amendment Document, which serves as the official legal document that contains the above changes. The changes are highlighted in yellow in the unofficial copy of the Ontario Amendment Document.

Email ontario.amendment.document@ontario.ca to obtain an Ontario Amendment Document.