Dealing With a Cannabis Farm

Finding or suspecting a tenant is growing weed in the house can be incredibly concerning for obvious reasons. It’s vital that landlords remain calm and go through the correct process. This includes recognising the warning signs, making clear records, contacting the police, and notifying insurers.

It might not be a situation you expected when putting your property on the rental market, but it does happen. Recent statistics suggest that cannabis is Britain’s most widely used illegal drug, with the entire cannabis market said to be worth £1 billion. As concerning as these figures are, you may also be wondering what the connection is between the demand for cannabis and your life as a landlord.

Unfortunately, unbeknownst to you, there could well be a connection, as there has been an increasing tendency since the early 2000s for cannabis to be cultivated in relatively small residential or domestic premises, rather than on large-scale commercial and industrial sites. That means your own property could be at risk of becoming the site of a cannabis farm. So, what should you do if you suspect a grow house at your rental property?

Why Should Landlords Be Concerned About Tenants Growing Weed In Their House?

The consequences of your property being used to cultivate cannabis could be dire. There is, first of all, the legal angle. Allowing any property that you own to be used for the cultivation or supply of cannabis is against the law, as outlined by section 8 of the Misuse of Drugs Act, 1971. (Gov.UK)

If you allow cannabis to be cultivated, produced, or supplied from premises for which you are the landlord, you could be hit by the same penalties as those actually conducting the activities. That could mean a significant fine and a lengthy prison sentence. 

There is also the risk of having your property seized, and even if the outcome is the best one possible in the circumstances, being arrested, questioned by police, and appearing in court can make for an extremely stressful and unpleasant several months. There’s also potential for financial ruin due to the resultant legal costs and loss of rental income, or the physical damage that can be caused to your property by someone using it for a cannabis farm. Examples of the latter may range from ceilings and walls being knocked through, to destroyed furniture, water damage, floorboard removal, and the ripping out of wiring.

How to Detect Whether a Tenant is Growing Weed in the House

A cannabis farm is easily recognisable from inside a property due to its green plants, irrigation systems, lighting, and ventilation fans. However, if the tenant is not permitting you to access the property, there are still some telltale signs that you may be able to pick up from the outside. 

It’s important to carry out property inspections regularly. This allows you to pay close attention to the condition of the property and activities inside the property. Inspections must be conducted at ‘reasonable times of the day’, with at least 24 hours’ written notice needing to be given to the tenant. If you are not allowed to inspect the property, or your access is prevented, then that may be a sign of illegal activity.

The following signs of cannabis growth are commonly recognised by various UK crime-prevention bodies.

• A strong and sickly sweet smell
• People arriving at and leaving the property at all times of the day and night
• Strong lights visible through chinks in the windows or under doors
• Blacked-out windows or permanently closed curtains
• Equipment such as ventilation fans or lighting racks is being taken into the property
• Condensation on the windows
• Bin bags filled with vegetation
• Constant whirring noises from ventilation and extraction fans
• Birds gathering on the roof, especially in colder conditions
• Lack of snow/frost on the roof when other houses in the area are covered in white
• A tenant refusing inspections or access
• Signs of electricity tampering

If you notice any of the signs (or multiple) of growing weed, it doesn’t automatically mean your tenant is definitely growing weed inside your property. There could be plenty of fair and legal reasons as to why some of the items listed above have been noted.

What to do if you suspect a Grow House at Your Rental Property?

If you strongly suspect your tenant is growing weed in the house, then you must not visit the property straight away. It may be tempting to go and have a look or carry out some further investigation, but that would put you at risk. If illegal activity is happening at the house, then it may be a dangerous place to visit.

The Police have warned that growing cannabis can be connected to organised crime groups where people inside the property are being exploited or controlled. The tenant may also react strongly if you accuse them of the crime. Instead, landlords should call the police immediately and follow the steps listed below.

1. Avoid speaking to the tenants – even after contacting the police, you will put yourself in danger if you confront the tenants.
2. Do not touch the wiring or other equipment – it may not be safe. The electrical system may have been tampered with
3. Record what you have found – make notes of what you see and your suspicions. This should include dates, times, smells, noises, visible changes, missed inspections, and any reports from neighbours.
4. Contact your insurer – tell your landlord’s insurance provider as soon as possible and follow their claims process.
5. Contact your letting agent and solicitor – If your property is being managed by a letting agent, inform them. You may need legal advice from your solicitor.

Treat Your Rental Property as Unsafe

Even after the police have visited the property and dealt with the issue, landlords should not assume that the property is safe after they have dealt with the tenant growing weed in the house. Landlords should follow any advice given by the police. 

Crimestoppers has warned that Cannabis farms can pose a serious fire risk because electrical meters are often bypassed or overloaded. After the police have dealt with the immediate issue, landlords can focus on making the property safe. You may need to sort out the following: 

• An electrical safety inspection
• A gas safety check
• A structural assessment
• Specialist cleaning
• Damp, mould, or water damage checks
• Pest or waste removal
• Locksmith support if keys may have been copied

Police in the United Kingdom have highlighted how growing cannabis can be linked to organised crime, exploitation, and modern slavery. In some cases, the actual tenant may not be living in the property. Instead, they may have someone who is forced to live there to tend plants. This reinforces why contacting the police is the safest response. This situation may be more complex and dangerous than it first appears.

Can you Evict a Tenant Growing Weed in my House?

Yes, usually landlords can evict a tenant growing weed with a section 8 notice. Ground 14 applies for this, where antisocial behaviour has been carried out at the property. Landlords do not need to give a notice period for this, as landlords can apply to the court straight away for a possession order to evict the tenant.

Since the changes introduced on the 1st May around the Renters’ Rights Act 2026, landlords can no longer give a section 21 no-fault eviction notice.

If you’re concerned about other illegal activity in your rental property, visit our advice centre. We give expert guidance on the issues landlords face, including neighbourly disputes, property occupants, pets, and more.