Ontario Carbon Monoxide Code Changes (Effective January 1, 2026)

What Property Owners, Managers, and Alarm Dealers Need to Know

As of January 1, 2026, important changes to Ontario’s carbon monoxide (CO) alarm code change requirements came into effect.

These updates expand placement requirements in residential and multi-residential occupancies — and they are already creating confusion in the industry.

Below is a simplified breakdown of what is changing, what is staying the same, and where interpretation matters.

What Is Changing in Residential Homes?

Previous Requirements (Before 2026)

CO alarms were required where a dwelling:

• Contains a fuel-burning appliance
• Contains a fireplace
• Has an attached garage
• Is supplied with heat from a fuel-burning appliance located outside the dwelling

New Requirements – Effective January 1, 2026

CO alarms must now be installed:

• Adjacent to each sleeping area
• On every storey of the dwelling
  • Including storeys without sleeping rooms

This is a significant expansion. Even if a level does not contain bedrooms, it may now require a CO alarm.

Multi-Residential Buildings & Care Facilities

Where Most of the Confusion Exists

The most common questions we are seeing relate to multi-unit residential buildings and care occupancies.

The Yes/No conditions outlined in the documentation include:

A CO alarm is required in a suite if:

• The suite contains a fuel-burning appliance or fireplace
• The suite is above, below, or adjacent to a service room containing a fuel-burning appliance
• The suite is above, below, or adjacent to a garage
• New for 2026: The suite is heated by forced air supplied from a fuel-burning appliance not located in the suite (e.g., central furnace serving multiple units)

The last condition is the key change.

Clarifying the Interpretation Questions

• If none of the above conditions apply, is a CO detector still required?
• If there is no fuel-burning appliance in the suite, is a CO alarm required?
• If the building uses a boiler system, does that trigger suite-level CO requirements?
• Does the new forced-air language apply only to central furnace systems?

The Practical Interpretation

If none of the listed exposure conditions apply to a suite, then a CO alarm is not newly required under this update.

However, the 2026 expansion adds a major trigger:

Suites heated by forced-air supplied from a fuel-burning appliance not located in the suite now require CO detection.

This primarily impacts:

• 8–12 unit walk-ups
• 3-storey multi-residential buildings
• Buildings with centralized furnace systems serving multiple units

Boiler systems (hydronic heating) are typically not treated the same way as forced-air central furnaces for this specific condition — but confirmation from the AHJ is always recommended.

Corridor & Common Area Requirements

The document also clarifies spacing requirements:

• CO detectors must be spaced no more than 25 meters apart in corridors (OBC Division B, Article 2.16.2.1(4)(b)(i)/(ii))
• At least one alarm is required in every section of a corridor separated by fire doors
• CO alarms are required in service rooms containing fuel-burning appliances
• CO alarms are required in public corridors heated by air supplied from a fuel-burning appliance

This is especially relevant for:

• Retirement homes
• Care facilities
• Large apartment corridors

Commercial Buildings

Retail, warehouses, and manufacturing occupancies are not directly impacted by the January 1, 2026 expansion.

CO placement in these buildings remains driven by:

• Occupancy classification
• Insurance requirements
• Presence of fuel-burning appliances

As noted in the document, these changes primarily expand Section 2.16 of the Ontario Fire Code.

Why This Matters for Property Owners & Dealers

These changes impact:

• Retrofit planning
• Budget forecasting for 2026
• Inspection preparedness
• Liability exposure
• Monitoring requirements

Multi-residential buildings with centralized forced-air heating are the largest group affected by the new language.

If you manage or service:

• Walk-up apartment buildings
• Retirement homes
• Mixed-use residential buildings
• Condo corporations

You should begin reviewing heating configurations now.

Key Takeaways

1. Single-family homes will require CO alarms adjacent to sleeping areas and on every storey.
2. Multi-unit buildings now include a new trigger: centralized forced-air heating.
3. Corridor spacing requirements remain strict (25m rule).
4. Boiler systems may not trigger the same suite-level requirements as forced-air systems — but always verify with the AHJ.
5. 2026 compliance planning should begin in 2025.

Need Help to Ensure Your Compliance?

The expanded carbon monoxide requirements will impact many residential and multi-residential buildings across Ontario — particularly those with centralized forced-air heating systems.

Whether you’re a property manager, condo board member, facility operator, or alarm dealer, early planning is the best way to avoid compliance issues, inspection delays, and unexpected retrofit costs.

Fire Monitoring of Canada can help you:

• Review your building’s heating configuration

• Determine whether the new 2026 triggers apply

• Plan compliant CO device placement

• Coordinate upgrades and monitoring integration

Don’t wait until inspection time.
Ontario carbon monoxide code changes came into effect at the start of 2026. Start your compliance review now.

Contact Fire Monitoring of Canada to schedule a compliance consultation.