Insulation Requirements for NZ Rental Properties: What You Need in 2026
Insulation is one of the most significant — and most expensive — Healthy Homes compliance items for NZ landlords. The standards set minimum R-values for ceiling and underfloor insulation, and many older properties fall short. Here is what you need to know about what is required and when.
What Is the Insulation Standard?
The Healthy Homes Insulation Standard (Regulation 6 of the Healthy Homes Standards) requires all NZ rental properties to have:
- Ceiling insulation with a minimum R-value of R2.9 in the North Island or R3.3 in the South Island (including Nelson, Marlborough, Tasman)
- Underfloor insulation with a minimum R-value of R1.3 in the North Island or R1.3 in the South Island, where the subfloor space is accessible
R-values measure thermal resistance — the higher the number, the better the insulation. These are installed R-values, which may differ from the product's stated R-value once the product compresses or ages.
When Did Compliance Deadlines Pass?
The Healthy Homes insulation deadlines have already passed:
- All new or renewed tenancies from 1 July 2021: the landlord must include a Healthy Homes compliance statement confirming the property meets the standards, or when it will
- All private rentals: must have met all 5 Healthy Homes standards (including insulation) by 1 July 2025
- Community housing providers: by 1 July 2024
If your property does not meet the insulation standard, you are already in breach as of July 2025. You should get it upgraded as a priority.
What Counts as "Accessible" for Underfloor?
Underfloor insulation is only required where the subfloor space is accessible — meaning a person or equipment can physically get under the house to install insulation. For properties on concrete slabs, underfloor insulation is not required.
The standard requires at least 400mm of clearance for the subfloor to be considered accessible. If the crawl space is too shallow, you are exempt from the underfloor requirement, though you should document this clearly.
Existing Insulation: Does It Meet the Standard?
Many NZ homes have some ceiling insulation that was installed years ago. The question is whether it meets the current R-value requirements. Old batts compress over time and lose effectiveness. Pink batts from the 1980s that were originally rated at R2.2 may now effectively be lower.
You need to check the R-value of existing insulation. If you do not know, an insulation installer can assess it for you — many do free assessments. If the existing insulation falls short, you can top-up (add a layer over existing batts) rather than replacing everything.
Does the Rental Warrant of Fitness Cover Insulation?
The Rental Warrant of Fitness (WOF) scheme run by some local councils is separate from the Healthy Homes Standards but covers many of the same items. Properties that pass the Rental WOF typically meet most Healthy Homes requirements. However, they are different schemes — meeting one does not automatically mean you meet the other.
Government Assistance
EECA (Energy Efficiency and Conservation Authority) offers the Warmer Kiwi Homes programme, which subsidises insulation and heating for low-income owner-occupiers. However, this programme is generally not available for rental properties. Landlords typically need to fund insulation upgrades themselves.
Some local councils and energy retailers have occasional subsidy or financing programmes for rental insulation. Check with your local council and energy retailer — the savings can be significant.
Recording Insulation Compliance
For every new tenancy, you must include a Healthy Homes compliance statement (part of the tenancy agreement) stating whether the property meets each standard and, if not, when it will comply. For insulation, this means recording:
- The R-value of existing ceiling insulation
- The R-value of existing underfloor insulation (or that it is not required)
- Whether these meet the standard
Keep documentation — quotes, invoices, product specifications — so you can demonstrate compliance if challenged. RentManager lets you record Healthy Homes compliance details per property, including insulation R-values and installation dates.