When a tenancy ends badly, the immediate priorities are often practical: repair damage, clean up, repaint, and prepare the property for its next occupants.
A fresh coat of paint can make a home feel renewed. But where there are concerns about methamphetamine use or contamination, appearance is not a reliable measure of condition. Paint may improve presentation; it does not establish whether contamination is present, where it is located, or whether the underlying risk has been properly managed.
That distinction matters more than ever.
A changed framework — and a changed mindset
New Zealand’s approach to methamphetamine contamination changed substantially in 2018. The framework of reference shifted from the 1.5 μg/100 cm² level in NZS 8510:2017 to 15 μg/100 cm² following the Gluckman Report.
The current Residential Tenancies (Managing Methamphetamine Contamination) Regulations 2026 now use those settings and also introduce a Maximum Inhabitable Level of 30 μg/100 cm². That upper level was adopted even though ESR advised HUD that there was insufficient evidence to define a maximum inhabitable level for methamphetamine.
For some owners and managers, these higher thresholds may create a misplaced sense that lower-level contamination is no longer worth investigating. A property may look clean, may have been repainted, and may not present an obvious problem — but none of that tells us what is on, within, or beneath the surfaces of the home.
The question should not be whether a property looks ready to re-let. It should be whether the owner has enough reliable information to make a responsible decision.
What new evidence adds to the picture
The recently published New Zealand Medical Journal study by Dr Muhammad Irfan and colleagues gives this issue fresh urgency.
Using results from properties tested both before and after the 2018 policy change, the researchers found that average contamination levels in the tested properties had risen by 51 percent. The study does not attribute that increase to any single property-management practice. It does, however, show that the problem has become more pronounced during the period in which New Zealand has operated under a more relaxed framework of reference.
The findings have also received attention across national platforms. In an interview with Newstalk ZB, Dr Irfan discussed what the results indicate about rising contamination and changing patterns of exposure in New Zealand homes.
Paint is maintenance, not an investigation
There is nothing inherently wrong with repainting a rental property. Painting is normal maintenance, and it is often necessary between tenancies.
The problem arises when a paintbrush becomes a substitute for investigation.
Methamphetamine contamination is not reliably visible. A clean-looking wall, ceiling or floor does not prove that contamination was never present, has been identified, or has been appropriately addressed. Nor does painting answer questions about other materials and areas in a property, including carpets, flooring, ventilation systems and frequently touched surfaces.
If there has been suspicious activity, known drug use, damage consistent with meth-related behaviour, information from neighbours, or unexplained concerns about a property, a cosmetic response alone leaves important questions unresolved.
A property owner who repaints first and asks questions later may be trying to solve a short-term tenancy or presentation problem. But they may also be deferring a more serious issue until it becomes more difficult, expensive and disruptive to manage.
The cost of false certainty
The risk is not simply contamination itself. It is acting with confidence when the relevant facts are unknown.
The public health implications of passive exposure remain a key concern, with reporting in the NZ Herald highlighting potential risks to children’s health and wider healthcare costs. At the same time, as noted in coverage by RNZ, scientific caution remains regarding the precise health effects at different exposure levels. That ongoing uncertainty makes reliable information more important, not less.
This uncertainty affects multiple stakeholders across the property sector:
- Prospective and current occupants, particularly children who have greater contact with floors and household surfaces.
- Owners and property managers making tenancy, maintenance and disclosure decisions.
- Purchasers relying on presentation rather than verified property condition.
- Insurers, lenders and other parties assessing a property’s history and risk profile.
- Owners facing higher testing, remediation or dispute costs after the issue emerges later.
As we outlined in Why a Freshly Painted Ex-Rental Should Raise Questions, fresh paint can create a compelling impression that a property has been fully restored. But a visual impression is not evidence.
Better property decisions begin with better information
The purpose of responsible meth risk management is not to create unnecessary alarm or impose unnecessary cost. It is to replace uncertainty with useful information before decisions are made that affect people, property and liability.
The latest research indicates that contamination levels in tested homes are increasing. At the same time, important uncertainty remains about health effects at different levels of exposure — uncertainty that the Gluckman Report itself said required further research.
Until that research is completed, owners and managers should be cautious about treating a property’s appearance as proof of its safety.
A fresh coat of paint can improve a home. It cannot verify its condition.
When there is a credible reason for concern, the better question is not, “Does it look fine now?” It is, “What do we actually know about this property?”