There is no provincial registry of former grow-op properties in Ontario. What exists instead is the order machinery in the Building Code Act, 1992: under section 15.2(4) a property standards order may be registered on title, and any person acquiring an interest after registration is deemed to have been served with it — so a title search is the single most useful check a buyer can make. Toronto’s Municipal Code Chapter 565 requires an owner to remediate and bars occupation until they do, but only engages once police identify the property to the City in writing, and does not require a professional report. Ottawa’s by-law is stricter: restoration under the direction of a professional engineer, a certificate of compliance, and orders registered on title. The federal limit is four plants per dwelling-house.
“Was this house a grow-op?” is one of the questions buyers most want answered and least often can be. Here is what actually exists to check, and what does not.
There is no provincial registry of former grow-op properties in Ontario. I searched ontario.ca and the major municipal and police sites; nothing of the kind exists. What does exist is better than nothing and almost nobody uses it: a title search.
The four-plant baseline
Since legalisation the legal line has been the federal Cannabis Act, section 12(4)(b), which makes it an offence for an individual to cultivate, propagate or harvest “more than four cannabis plants at any one time in their dwelling-house”.
Ontario added a layer in 2025. Section 13.1 of the Cannabis Control Act, 2017, in force 1 January 2025, prohibits cultivating cannabis in a dwelling in which child care is provided. That is a recent change and easy to miss.
What actually governs a former grow-op is municipal
There is no grow-op-specific provision in the Ontario Building Code. The legal hook is property standards and unsafe-building orders under the Building Code Act, 1992, plus municipal by-laws — all applied after the fact.
Toronto, Municipal Code Chapter 565, dated 27 September 2007, defines a grow operation as any property that the Toronto Police Service, OPP or RCMP “has identified in writing to the City” as having contained one. The owner must immediately:
- Remove all equipment or materials used in the operation;
- Remove and restore any alteration to the property;
- Repair any damage … including, but not limited to, mould or water damage;
- Obtain and comply with all inspections, orders, permits and approvals required for lawful use.
And: “No person shall allow a property … to be used as a dwelling … unless it has been remediated, restored or repaired as required.”
A gap in the Toronto by-law worth knowing. Chapter 565 does not require a report by a qualified professional. Compare Ottawa’s By-law 2012-402, which requires restoration “under the direction of a professional engineer”, requires examinations and tests, issues a certificate of compliance, and lets the Director register the order on title until that certificate issues. In Toronto the trigger also depends on police having identified the property to the City in writing — so a property never identified may never enter the system at all.
The title search is the real tool
Section 15.2(4) of the Building Code Act, 1992 is the provision to know:
“The order may be registered in the proper land registry office and, upon such registration, any person acquiring any interest in the land subsequent to the registration of the order shall be deemed to have been served with the order … and, when the requirements of the order have been satisfied, the clerk of the municipality shall forthwith register … a certificate that such requirements have been satisfied, which shall operate as a discharge of the order.”
Equivalent registration machinery applies to other orders under the Act, including unsafe-building orders under section 15.9. Section 15.5(1) allows an officer to issue a certificate of compliance where a property meets the standards.
So: a registered property standards or unsafe-building order is discoverable on title, and a buyer who acquires an interest after registration is deemed to have been served with it. That is not a technicality — it means you inherit the order whether or not you knew. It is also why your lawyer’s title search is the most useful grow-op check available to you.
The second tool: municipal building records
Toronto will disclose drawing records of prior permit applications. Residential building plans are available for permits submitted after 31 December 2006, along with site plans, surveys and drain plans. The fee is $76.98 per disclosure, effective 1 January 2026, processed within 30 business days.
Note the limit: that page does not list inspection records or orders as routinely disclosable. For those you are looking at a freedom-of-information request or, more practically, the title search. And thirty business days does not fit inside a typical conditional period, so this is a question to raise early or to handle through your lawyer.
What to do
- Have your lawyer search title and specifically look for registered orders under the Building Code Act.
- Ask the seller directly, in writing. A false answer to a direct written question is a very different matter from silence.
- Order building records early if the history concerns you — thirty business days.
- Look for the physical signs and have them assessed: altered electrical service, unexplained circuits, patched roof vents, replaced drywall of a different age, mould staining, high humidity damage.
- Do not rely on the absence of a record. There is no registry, and in Toronto the by-law only engages once police identify the property to the City in writing.
Worried about a property’s history?
The check that actually works here is a title search, and it needs to be instructed properly — your lawyer is looking for registered orders under the Building Code Act, not just for liens. If the question matters to you, raise it before you write, because building records take thirty business days and that does not fit in a normal conditional period. Tell me the property and I will help you sequence the checks and frame the written question to the seller.
connect@jatindua.com · 437-987-1925 · Book a free consultation
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Frequently asked questions
Is there a registry of former grow-op houses in Ontario?
No. Searches across ontario.ca and major municipal and police websites located no provincial or municipal registry of former grow-op properties. The only Ontario results were the general land registry and police record check pages. What a buyer can check instead is title, because orders under the Building Code Act, 1992 can be registered against a property.
How can a buyer find out if a house was a grow-op?
The most useful tool is a title search. Section 15.2(4) of the Building Code Act, 1992 provides that a property standards order may be registered in the land registry office and that any person acquiring an interest in the land after registration is deemed to have been served with the order, with a certificate registered on satisfaction operating as a discharge. Equivalent machinery applies to unsafe building orders under section 15.9. In Ottawa, a grow-op remediation order can itself be registered on title under By-law 2012-402. A municipal building records request is a second route, though inspection records and orders are not listed as routinely disclosable in Toronto.
What does Toronto require after a grow-op?
Municipal Code Chapter 565 requires the owner immediately to remove all equipment or materials used in the operation, remove and restore any alteration to the property, repair any damage caused including but not limited to mould or water damage, and obtain and comply with all inspections, orders, permits and approvals required for lawful use. It also prohibits allowing the property to be used as a dwelling unless it has been remediated. Note two limits: the chapter only applies where the Toronto Police Service, OPP or RCMP has identified the property in writing to the City, and it does not require a report by a qualified professional.
How many cannabis plants can be grown at home?
Four. Section 12(4)(b) of the federal Cannabis Act makes it an offence for an individual to cultivate, propagate or harvest more than four cannabis plants at any one time in their dwelling-house. Ontario added section 13.1 to the Cannabis Control Act, 2017, in force 1 January 2025, prohibiting cultivation of cannabis in a dwelling in which child care is provided.
Does the Ontario Building Code have grow-op rules?
No. There is no grow-op-specific provision in the Building Code. The building-law mechanism is the property standards and unsafe building order machinery in sections 15.1 to 15.5 and 15.9 of the Building Code Act, 1992, together with municipal property standards by-laws, applied after the fact. Remediation work itself — rewiring, mould removal, structural repair, ventilation changes — requires the ordinary permits and inspections.
How long does a Toronto building records request take?
The City states that requests are processed within 30 business days of receipt. Drawing records of prior permit applications are available, with residential building plans available for permits submitted after 31 December 2006, along with site plans, surveys and drain plans. The record disclosure fee is $76.98 for each disclosure, effective 1 January 2026. Thirty business days will not usually fit inside a conditional period, so this is a check to start early.
Related reading
- Home inspection in Ontario: still not a licensed profession
- Radon in Ontario homes: the 91-day rule most tests fail
- Asbestos and vermiculite: what the rules actually require
- Knob-and-tube and aluminum wiring: neither is illegal
Sources
Every figure on this page traces to one of these, and each was read on 1 September 2026. Primary sources only — statute, regulation, and the government or agency that administers the rule. Where I could not verify something from a primary source, the page says so instead of guessing.
- Cannabis Act, S.C. 2018, c. 16. Justice Laws Website, current to 21 June 2026. Section 12(4)(b) makes it an offence for an individual to cultivate, propagate or harvest more than four cannabis plants at any one time in their dwelling-house. Accessed 1 September 2026.
- Cannabis Control Act, 2017, S.O. 2017, c. 26, Sched. 1. Government of Ontario e-Laws, read 2 September 2026. Section 13.1, in force 1 January 2025, prohibits cultivating cannabis in a dwelling in which child care is provided. Accessed 1 September 2026.
- Toronto Municipal Code Chapter 565, Marijuana Grow Operations (PDF) — City of Toronto. City of Toronto, dated 27 September 2007. Defines a marijuana grow operation as any property identified in writing to the City by the Toronto Police Service, the Ontario Provincial Police or the Royal Canadian Mounted Police as having contained one. Requires the owner immediately to remove all equipment and materials, restore alterations, repair damage including mould or water damage, and obtain all required inspections, orders, permits and approvals, and prohibits occupation of the property until it has been remediated. The chapter does not require a report by a qualified professional. Accessed 1 September 2026.
- Marijuana Grow Operation Remediation By-law No. 2012-402 — City of Ottawa. City of Ottawa, enacted 14 November 2012. Requires owners to discontinue occupancy until the property has been remediated and a certificate of compliance issued, to carry out restoration under the direction of a professional engineer, and to have examinations and tests conducted. The Director may register an order under the by-law on the title of the property, released once a certificate of compliance is issued. Accessed 1 September 2026.
- Building Code Act, 1992, S.O. 1992, c. 23. Government of Ontario e-Laws, read 2 September 2026. Section 15.2(4) permits an order to be registered against the title to a property, and a subsequent purchaser is deemed to have been served with it. This is the mechanism that makes an outstanding order discoverable on a title search. Accessed 1 September 2026.
- Request building records — City of Toronto. City of Toronto, fee effective 1 January 2026. States that drawing records of prior permit applications are available, that residential building plans are available for permits submitted after 31 December 2006, that the record disclosure fee is $76.98 for each disclosure, and that requests are processed within 30 business days. Inspection records and orders are not listed as routinely disclosable. Accessed 1 September 2026.
- O. Reg. 163/24, Building Code, under the Building Code Act, 1992. Government of Ontario e-Laws, read 2 September 2026. The current Ontario Building Code, which revoked and replaced O. Reg. 332/12 on 1 January 2025. It adopts the National Building Code of Canada 2020 together with Ontario amendments. Because the technical content is adopted by reference it is not reproduced on e-Laws. Accessed 1 September 2026.
About the author — Jatin Dua, Broker of Record
I’m the Broker of Record at RE/MAX Quantum Realty, 799 The Queensway in Etobicoke, and I work with buyers and sellers across the west GTA. I am not an inspector, an engineer, an electrician or a remediation contractor, and nothing on this page is a substitute for one.
What I can do is read the primary source and quote it accurately. Everything below comes from Health Canada, the Government of Ontario, a regulator or a municipality, with the date the source itself carries, so you can check it rather than take my word for it. Where a widely repeated claim turns out not to be in any official document, the page says so. connect@jatindua.com or 437-987-1925.