Quebec Condo Garage Ventilation: Requirements and Testing

In a divided co-ownership, indoor garage ventilation directly affects occupant health and regulatory compliance. Carbon monoxide (CO) and nitrogen dioxide (NO₂) emissions from vehicles must be evacuated effectively. In Quebec, the RBQ framework and building codes require adequate ventilation, as well as regular maintenance and inspections. This article, current as of 2026-07-07, summarizes the essentials for your syndicate and board of directors (board).

Quebec legal and regulatory framework (current as of 2026-07-07)

• Syndicate responsibility: Under the Civil Code of Quebec, the syndicate must ensure the preservation of the building and the maintenance of the common portions, which generally include the garage (see section 1039 C.C.Q., as well as obligations related to common expenses, see section 1064 C.C.Q.). Reference: LégisQuébec – Civil Code of Quebec.
• Applicable codes: The Quebec Construction Code (B-1.1, r. 2) and Safety Code (B-1.1, r. 3) set out technical requirements covering, among other things, the mechanical ventilation of indoor parking facilities and equipment maintenance. References: LégisQuébec – Construction Code (B-1.1, r. 2) and LégisQuéQuébec – Safety Code (B-1.1, r. 3).
• RBQ guidelines: The Regie du batiment du Quebec (RBQ) publishes prevention advice on indoor parking facilities, air quality, the presence of CO and ventilation system maintenance. Reference: RBQ – Carbon Monoxide and Indoor Parking Facilities.

In practice, two approaches are common in enclosed garages: continuous low-flow ventilation, or demand-controlled ventilation activated by sensors (CO/NO₂) that start the fans in stages. The choice depends on the original design and the code requirements in effect when the building was constructed or when compliant renovations were carried out. Any modification must be performed by a qualified contractor in accordance with accepted practices.

Practical requirements for your condo garage

These are the common elements your syndicate should find in a compliant, well-managed indoor garage:

• Functional mechanical ventilation: exhaust fans and, where necessary, a fresh-air supply, with ducts in good condition and operational dampers.
• Detection and control: calibrated CO sensors (and often NO₂ sensors) connected to a controller that adjusts the fans according to safety thresholds.
• Exhaust outlets to the outdoors: exhaust outlets must be unobstructed and sufficiently far from air intakes and openings leading to private portions, to prevent contaminants from returning inside.
• Access and safety: clearly identified emergency shut-off devices, signage, sufficient lighting in mechanical rooms and clear access routes for maintenance.
• Partitions and airtightness: fire doors that close properly and weatherstripping in good condition, to limit the transfer of stale air to stairwells and corridors (interior common portions).
• Technical documentation: mechanical plans, maintenance manuals, a list of sensors and calibration dates, kept in the maintenance logbook / EUC and accessible to the board.

If your co-ownership has a history of odour complaints, frequent CO alarms or condensation in the garage, a complete inspection by a ventilation contractor and, where necessary, a building mechanical engineer is required.

Testing and maintenance: what, who and when

To limit risks and meet your maintenance obligations, establish a routine inspection and testing schedule. The RBQ emphasizes the importance of maintaining systems that affect air quality and occupant safety. Reference: RBQ – Building Safety.

Usual frequencies (good practices in divided co-ownership):

• Monthly visual inspection by your condominium manager or caretaker: indicator status, unusual noises, fresh-air filters where applicable and fire doors.
• Seasonal maintenance (2×/year) by a specialized contractor: cleaning motors/wheels, checking belts, tightening, dampers and bearings; maintenance report.
• Functional testing at least once a year: activation of the fans by the sensors, checking speeds/stages, safety tests and signage.
• Calibration of CO/NO₂ sensors according to the manufacturer’s recommendations (often every 6 to 12 months), with a calibration certificate.

Typical annual testing:

• Sensors: test with calibration gas or a simulator to validate the response and thresholds; replace the sensor if calibration fails.
• Fans: measure electrical current, check the direction of rotation, vibrations and anti-vibration systems.
• Airflows/air quality: spot measurements of CO/NO₂ during a test scenario (engines idling under supervision) and qualitative verification of airflow with smoke where necessary.
• Safety interactions: test emergency shut-offs, local alarms, the relay to the control panel and any signal to the fire alarm system where there is an interlock.
• Airtightness: simple differential-pressure testing between the garage and corridors (smoke/sheet test) to ensure that garage air does not migrate to the common portions.

Document management:

• Keep all reports and certificates in your maintenance logbook / EUC and report the results to the board. Major findings should be recorded in the minutes of a board meeting and then summarized at the annual general meeting to inform the co-owners.
• Schedule urgent corrective work as soon as equipment is found to be non-compliant or defective, and include major replacements in the multi-year planning for the contingency fund.

If you would like to delegate the coordination of visits, testing and non-compliance follow-up, see our operations management service. For archiving reports and maintenance contracts and preparing the annual general meeting, also see our administrative management service. You can browse more practical advice on our blog.

Recommended testing and frequencies (overview)

Note: adapt the frequencies to the manufacturers’ recommendations and the garage’s actual use (traffic, door-opening cycles and weather conditions).

Board responsibilities and budget management

The board must:

• Adopt a preventive maintenance procedure for the garage and appoint someone to oversee it.
• Budget for maintenance contracts and annual testing through condo fees (common expenses), and include major replacements of fans, controllers and sensors in contingency fund planning.
• Keep the maintenance logbook / EUC up to date, archive test reports and include a summary at the annual general meeting. Where necessary, amend the by-laws of the immovable (e.g., recording CO incidents and restrictions on idling).
• Verify the contractor’s contractual compliance (appropriate RBQ licence, insurance and technical data sheets) and ensure that access to mechanical rooms is controlled.

For example, one syndicate we assist reduced nuisance activations by having its sensors recalibrated and adjusting the ventilation stages according to peak hours. This approach reduces noise and energy consumption while maintaining safety.

For structured assistance covering contract management, calls for tenders and multi-year planning, see our services and learn more about who we are.

Signs of a defective system and immediate action

Signs to watch for:

• Persistent exhaust odour, haze or black dust on surfaces.
• Frequent CO alarms, or fans that do not start despite vehicles being present.
• Excessive condensation, premature corrosion on ducts and anchors.
• Unusual noise, vibrations or alarm indicators on the controller.

Immediate action in the event of a CO alarm or symptoms (headaches, dizziness):

1. Evacuate the garage and maximize ventilation by activating the higher stages if this can be done safely.
2. Temporarily prohibit vehicle access and call a qualified contractor to diagnose the cause.
3. If symptoms are present, call emergency services. Then document the incident and the steps taken; record everything in the board’s minutes and send a notice to the co-owners.

Frequently asked questions

Q1. How often should CO/NO₂ sensors be calibrated?
A. Follow the manufacturer’s and contractor’s recommendations; in divided co-ownership, an interval of 6 to 12 months is common. Document each calibration and retain the certificates.

Q2. Who pays for garage ventilation testing and maintenance?
A. These are common-portion expenses paid through common expenses. Major replacements (e.g., end-of-life fans) should be planned through the contingency fund.

Q3. Must the ventilation operate 24/7?
A. This depends on the building’s design and the applicable requirements. Many garages use demand-controlled ventilation with sensors. Do not change the settings without professional advice.

Useful references:

• RBQ – Carbon Monoxide, Indoor Air and Indoor Parking Facilities
• LégisQuébec – Quebec Construction Code (B-1.1, r. 2)
• LégisQuébec – Quebec Safety Code (B-1.1, r. 3)
• RGCQ – Resources and Good Practices in Divided Co-ownership

This article provides general information and does not constitute legal advice. Consult a lawyer or notary regarding your situation.

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