Building Code Changes in effect as of January 1, 2025 (Summary)

The 2024 Ontario Building Code came into effect on January 1, 2025.

There’s a three month grace period until March 31, 2025, allowing the use of the 2012 Ontario Building Code for applications with drawings that were mostly done before January 1, 2025.

Here’s a summary of the key changes which will affect the built environment in Ontario:

General, Division A and Division C:

• Definition of House: The definition of “house” has been removed.
• Definition of Secondary Suite: A new definition for “Secondary Suite” has been added. This doesn’t mean a third suite isn’t allowed, but it provides some exemptions for houses with up to two suites.
• Referenced Documents/Standards: All referenced documents and standards can be updated to the latest effective date up to July 15, 2019, unless a more recent date is specified.
• Record of Site Condition: Now required for occupancy, but only if the building permit was issued as a conditional permit with the Record of Site Condition (R.O.S.C.) as part of the conditions. Normally, a R.O.S.C. is required before permit issuance.
• Ramp Definition: A ramp is now defined as any surface with a slope greater than 1 in 20 (more than 5%).

Part 3: Fire Protection, Occupant Safety and Accessibility

• Fire Separation Penetrations: Tight-fitting penetrations are no longer allowed. They must be a tested fire stop system or non-combustible cast-in place. Non-combustible electrical boxes can have a max 3mm gap without a fire stop.
• Fire Alarm Notification: Fire alarms must notify the fire department directly, not through a municipal system.
• Standpipe Systems: Must now achieve 690kPa (100psi) residual pressure, up from 450kPa.
• Interconnected Floor Space: Simplified smoke control requirements and added draft stops and limits on combustible content.
• Egress from Sprinklered Suites: Reduced maximum area and travel distance for a single egress door.
• Tactile Attention Indicators: New locations added, like the top of unenclosed stairs and drop-off edges over 300mm.
• Exit Signage: Signs with the word “EXIT” and tactile form required next to each exit door in certain buildings.
• Barrier-Free Entrances: All exterior pedestrian entrance doors must be barrier-free and have power door operators.
• Barrier-Free Path of Travel: Must extend to designated barrier-free parking.
• Barrier-Free Signage: Required in more locations like washrooms, showers, elevators, and parking spaces.
• Tactile Signs: Must have Braille and be installed next to the latch side of doors.
• Barrier-Free Door Widths: Reduced back to 850mm clear opening.
• Barrier-Free Elevators: Additional dimensional requirements added.
• Universal Shower/Change Rooms: New requirements for public/customer/employee facilities.
• Barrier-Free Service Counter: New requirements added.

Part 5: Environmental Separation

• Air Barrier: Required to minimize radon and soil gas to acceptable levels and must be continuous at control joints, junctions, and penetrations.

Part 6: Heating, Ventilating and Air-conditioning

• Reorganization: Requirements have been reorganized under new articles/headings.
• Ventilation and Air Duct Systems: For Part 9 dwellings or houses, now moved to 9.32. and 9.33.

Part 7: Plumbing

• Nominal Pipe Size (NPS): Definition added.
• S-Traps: No longer prohibited but still need a vent connection.
• Tracer Wire: New type allowed: 12 gauge copper-coated steel wire.
• First Manhole: Can be up to 75m from the building, up from 30m.
• Clothes Washer Tray Drain: Must be 2 inches.
• Vent Pipe: Must end at least 1.8m from a property line.
• Air Admittance Valves: Must be at least 100mm above the flood level of the fixture.

Part 8: Sewage Systems

• Septic Tanks: Now require a safety grate in all access openings.

Part 9: Housing and Small Buildings

• Ceiling Heights: Ceiling heights for secondary units in new construction can now be lower.
• Door Heights: Doors in secondary suites can be as low as 1890mm.
• Stair Height: The height over stairs in secondary suites can be 1850mm.
• Stair Nosing’s: The top edge of stair nosing’s must be rounded or beveled between 6mm and 14mm, or 3mm if using resilient flooring.
• Stair Openings: The maximum opening on the sides of stairs, between stair treads and the bottom rail of the guard, is now 150mm.
• Egress for Upper Units: In some cases, the upper unit of a house with two units needs a separate exit.
• Fire-Rated Steel Columns: A simplified method for protecting fire-rated steel columns in houses with secondary suites has been added.
• Smoke-Tight Barriers: Houses with secondary suites now need “smoke-tight barriers” instead of “fire separations.” This includes:
  • Assemblies covered with 5/8” Type X drywall to prevent smoke spread.
  • Floors in houses with secondary suites don’t need to be fire separations.
  • Penetrations must be sealed to be smoke-tight.
  • The entire house is considered a single fire compartment.
  • Service rooms and public corridors in two-unit houses only need smoke-tight barriers with 5/8” Type X drywall.
  • Doors in smoke-tight barriers don’t need a fire protection rating but must maintain the smoke-tight barrier.
  • A shared exit for two suites still needs a fire separation unless it can be considered common space or a public corridor.
  • Storage garages serving more than one unit need a 1-hour fire separation; otherwise, a smoke-tight barrier is enough.
• Walls at 135 Degrees: Walls meeting at a 135-degree angle can use the same 5/8” Type X protection for two-unit houses.
• Spatial Separation: Specific rules apply to houses with two units or no units above another.
• Smoke Alarms: All smoke alarms in a house with two units must be interconnected, either wired or wirelessly.
• Soil Gas Control: The code now requires a rough-in for a future depressurization system and the floor slab designed for air barrier and damp proofing.
• Sump Pits: New minimum sizes for sump pits: at least 750mm deep with a surface area of 0.25 square meters.
• Crawlspace Ground Cover: Ground cover in heated crawlspaces must be a complete air barrier with all penetrations sealed.
• Roof Access Hatch: Slight change in size for roof access hatches within individual dwelling units.
• Connectors for Treated Wood: Connectors in contact with treated wood must be made of stainless steel or hot-dipped zinc-coated galvanized steel to a specific standard.
• Span Tables: New span tables have been added at the end of Part 9.
• Vinyl Siding Fastening: Fasteners must be installed in the center of the slots to allow for expansion and contraction.
• Vertical Vinyl Siding: Cannot be fastened directly to the sheathing; must go through to framing members.
• Carbon Monoxide Alarms: New rules for carbon monoxide alarms, including:
  • Required on each storey, even without bedrooms.
  • Required in combination living and sleeping areas.
  • Required in bedrooms with a fuel-burning appliance or flue pipe.
  • Required in bedrooms sharing a wall/floor/ceiling with a storage garage, attic, crawlspace, or room with a fuel-burning appliance.
  • Required in public corridors serving multiple residential suites heated by a forced-air fuel-burning appliance.
  • Required in service rooms and rooms with fuel-burning appliances or laundry drying equipment outside of a dwelling.
  • Must be interconnected and activated within a house with two units, including common areas.
  • Must have a visual signal component, except for completely battery-operated alarms.

Please keep in mind that the Ontario’s Building Code sets rules for new construction, renovations, and changes in use. These rules apply to new construction and not to existing buildings or parts that aren’t being changed.

A free digital copy of the code can be obtained here: https://www.ontario.ca/form/get-2024-building-code-compendium-non-commercial-use

Please contact the building department should you need more details.