Outcomes from the New Zealand Tenancy Tribunal after a review of policy on residential housing methamphetamine contamination.

The New Zealand policy response to methamphetamine contamination of housing has resulted in reduction of public housing stock, award of significant remediation costs and evictions. The New Zealand Tenancy Tribunal (NZTT) has adjudicated methamphetamine contamination disputes between tenants and landlords without specific guidance in legislation. A 2018 scientific review by the Chief Science Advisor prompted a significant increase in the contamination threshold. To evaluate the outcomes from this policy change, we compared 195 NZTT orders following the threshold increase with 685 orders from before the threshold increase. Landlords remain as major applicants to the NZTT. Cases involving public housing tenancies dramatically decreased from 33% (pre threshold increase) to none. Mention of baseline testing and methamphetamine test results became more prominent after the threshold increase. The average remediation costs decreased from NZ$10,300 to NZ$3,500 per order, perhaps reflecting fewer rooms of houses requiring remediation under the new threshold. Applicants and respondents continued to support their claims based on different scientific thresholds and reports. Discrepancies between adjudicators' interpretations of test results and the threshold to apply continued to generate inconsistencies in NZTT decisions. Legislative and regulatory guidance is still needed to consistently and equitably resolve these disputes.