Meth contamination: the new rules for rental properties

For years, landlords were left to navigate methamphetamine contamination with guidelines that were confusing and often contradictory. That changed on 16 April 2026, when the Residential Tenancies (Managing Methamphetamine Contamination) Regulations came into force. They set clear, legally binding rules for testing, decontamination and keeping tenants informed.

The key thresholds

• Above 15µg/100cm²: the affected area must be decontaminated.
• Above 30µg/100cm²: the property is treated as uninhabitable.

These levels are much higher than the old 1.5µg/100cm² figure many landlords will remember. They reflect scientific advice that low levels of residue from meth use, as opposed to manufacture, are unlikely to cause health problems.

When testing is required

Under the regulations, professional testing is required if:

• The Police or your local council tell you that meth was likely manufactured at the property, or
• A legally valid screening test shows results above 15µg/100cm²

Testing and decontamination must follow New Zealand Standard NZS 8510:2017, as modified by the regulations. Detailed testing must be done by a qualified professional, and the person who tests the property can't be the same person who does the decontamination.

Keeping your tenants informed

• Give tenants at least 48 hours' notice before entering to test.
• Tell tenants when testing is required, and keep them updated throughout the process.
• Give all existing tenants a copy of the results in writing within 7 days of receiving them.

If the property is contaminated

If testing shows contamination above the threshold, you must arrange for the property to be decontaminated as soon as practicable. Depending on the level of contamination and who was responsible, tenants may be entitled to a rent reduction or to end the tenancy. If the property is uninhabitable, additional rules apply, and the tenancy may need to end.

If a tenant caused the contamination, you may be able to recover the costs through the Tenancy Tribunal. It's also worth checking your landlord insurance policy now, so you know what's covered and what conditions apply, such as regular inspections or testing between tenancies.

Practical steps for landlords

• Consider baseline testing between tenancies. A clear result at the start of a tenancy makes it much easier to show when any contamination occurred.
• Keep records of every test, including the date, who did it and the results.
• Inspect regularly and watch for warning signs such as unusual chemical smells, stained surfaces, blacked-out windows or heavy security.
• Screen tenants carefully, including previous landlord references and Tenancy Tribunal checks.
• Use qualified professionals for any testing beyond a basic screening test.

Good tenants are your best protection

Careful tenant selection is the first line of defence against problems like meth contamination. Tenant Finder runs thorough credit, background and reference checks on every applicant, helping you choose a tenant who'll treat your property with respect.

This article is general information only and isn't legal advice. For the full rules, see the meth guidance on tenancy.govt.nz.