Since the legalization of cannabis in Canada in 2018, owners and managers of multi-residential buildings have faced new challenges. Home cultivation, permitted by federal law, raises important questions regarding property management, insurance, and landlord-tenant relations.
The Legal Framework in Quebec
Quebec legislation strictly regulates the personal cultivation of cannabis. Unlike other Canadian provinces, Quebec completely prohibits the cultivation of cannabis plants at home for recreational use. This prohibition applies to both homeowners and tenants, regardless of the type of dwelling.
However, cultivation for medical purposes remains permitted for those with a Health Canada authorization. This exception creates a gray area that landlords must navigate with caution.
Risks for Multi-Unit Buildings
Cannabis cultivation, even legal and medical, poses several risks for residential buildings:
Structural Damage and Moisture Problems
- Excessive humidity generated by indoor cultivation promotes mold growth
- Inadequate ventilation systems can damage walls, ceilings, and floors
- Chronic condensation affects air quality throughout the building
Insurance Complications
- Many insurers exclude damage related to cannabis cultivation
- Insurance premiums can increase significantly
- Failure to declare a crop may invalidate insurance coverage
Impacts on other occupants
- Persistent odors affect neighbors’ comfort
- Excessive electrical consumption can overload building systems
- Unauthorized modifications to the electrical system pose a fire risk

Your Rights and Obligations as a Landlord
As a landlord or property manager, you have several tools at your disposal to protect your investment. The lease is your first line of defense: you can include clauses prohibiting the cultivation of cannabis, even for medical purposes, citing legitimate reasons such as the protection of the building and the comfort of other tenants.
Regular inspections, carried out with respect for the right to privacy, allow for the rapid detection of any unauthorized activity. Clearly communicating your policies from the moment the lease is signed can prevent misunderstandings.
What to do in case of unauthorized cultivation?
The discovery of an unauthorized cannabis grow requires swift but methodical action. Document the situation with photos and written reports, then send a formal notice to the tenant demanding the immediate cessation of the activity.
If the tenant has a medical permit, the situation becomes more complex. You will need to demonstrate that the grow causes actual damage or presents serious risks to the building or other occupants. This is where air quality and mold detection tests become your best allies. These professional analyses provide objective and irrefutable evidence to support your legal efforts.
In the event of persistent non-compliance, recourse to the Administrative Housing Tribunal may be necessary to enforce your rights and protect your property.

The Importance of Professional Management
Faced with these complex issues affecting real estate law, insurance, and public health, professional expertise makes all the difference:
Navigating Legal Implications
- Laws are constantly evolving and vary by jurisdiction
- A procedural error can jeopardize your legal recourse
- Professionals stay up-to-date on regulatory changes
Rigorous management and documentation
- Meticulous monitoring of leases and specific clauses
- Consistent application of your policies across all your buildings
- Appropriate and complete documentation in the event of a dispute in court
Balanced protection of interests
- In-depth knowledge of the nuances of real estate law
- Ability to act quickly to protect your investment
- Simultaneous respect for tenant rights and your legal obligations
Early detection: your best protection
Don’t wait until the damage is visible to the naked eye. Professional air quality and mold testing detects problems before they become catastrophic. These analyses allow you to intervene quickly, protect the health of your tenants, and provide tangible evidence in the event of an insurance claim or legal action.
Investing in these preventive tests can save you thousands of dollars in repairs and protect your property’s long-term value.
Protect your investment now
Growing cannabis at home is a real challenge for owners of multi-unit buildings. It’s a delicate balance between complying with legislation, protecting your assets, and maintaining a healthy environment for all your tenants.
Experts can guide you every step of the way, from prevention to intervention, with concrete and measurable solutions. Certified testing gives you peace of mind and the tools you need to take effective action.

Contact Benjel today for a comprehensive assessment of your properties. Protect your investment with reliable data and the expertise of a team that understands your challenges.
Visit benjel.ca or call us to discover how our services can transform your property management.
Frequently Asked Questions
1. Can mold tests prove a past cannabis grow?
Yes. Professional mold and air quality tests detect abnormal humidity levels and spores resulting from a previous grow. These analyses provide essential objective evidence for insurance claims or proceedings before the Administrative Housing Tribunal.
2. Can a tenant grow cannabis on their balcony or terrace?
No. The Quebec ban applies everywhere in the residence, including balconies, terraces, yards, and private gardens. Outdoor cultivation is also prohibited, even with only one or two plants. The location does not change the illegality of the activity in Quebec.
3. What should I do if I discover a grow after the tenant has moved out?
Immediately document with photos and videos. Have professional mold and air quality tests conducted to assess the damage. Obtain repair quotes. You can sue the former tenant before the Administrative Housing Tribunal to recover costs within one year of their move out.
4. Can neighbors file complaints about cannabis odors?
Yes. Neighbors can file complaints with you, the municipality, or the police. Excessive odors constitute a nuisance and a disturbance of the enjoyment of other occupants. These complaints strengthen your case if you need to initiate eviction proceedings before the Tribunal.
5. What specific clause should I add to my lease regarding cannabis?
Include an explicit clause prohibiting the cultivation and possession of cannabis plants, seeds, and cuttings, even for medical purposes. Specify the consequences: termination of the lease and financial liability for any damages. Have this clause signed separately to confirm the tenant’s understanding.