Ceiling and underfloor insulation has been compulsory in all rental homes since 1 July 2019. The healthy homes insulation standard builds on the current regulations and some existing insulation will need to be topped up or replaced.

This page explains the healthy homes insulation standard with compliance dates beginning 1 July 2021. For information on the current insulation requirements, visit the current insulation requirements page.  

Insulation stops heat escaping from the house. In general, the better insulated a home is, the more it will retain heat. This means:

  • it will usually cost less to heat the property
  • the property will be drier
  • the property will be less prone to mould.

All private rentals must comply with the healthy homes standards within 90 days of any new or renewed tenancy after 1 July 2021, with all private rentals complying by 1 July 2024. All boarding houses must comply by 1 July 2021. All houses rented by Kāinga Ora (formerly Housing New Zealand) and registered Community Housing Providers must comply by 1 July 2023.

More detail about the insulation standard is available in the guidance document:

Download the insulation guidance document. [PDF, 2.6 MB]

What is the required level for insulation?

Insulation requirements  are measured by R-value. R-value is a measure of resistance to heat flow. The higher the R-value, the better the insulation.

Minimum R-values vary across New Zealand. Check what zone your property is in using the map below.

Zone 1 — ceiling R 2.9, underfloor R 1.3

Zone 2 — ceiling R 2.9, underfloor R 1.3

Zone 3 — ceiling R 3.3, underfloor R 1.3

The R-value of new insulation is on the product packaging. For existing insulation, check in the ceiling or underfloor space as the R-value from the packaging may be stapled to a beam. You can also measure the thickness yourself or consult a professional insulation installer. Existing ceiling insulation that was installed before 1 July 2016 must be at least 120mm thick.

Ceiling insulation that is less than 120mm thick is acceptable if the landlord can prove:

  • the insulation’s R-value met the minimum R-values (2.9 or 3.3 depending on the climate zone) when it was installed, and
  • the insulation’s thickness has not degraded by more than 30% (compared to when it was installed).

Insulation must be installed in accordance with New Zealand Standard 4246:2016.

All existing insulation must still be in reasonable condition to meet the requirements. This means there should be no mould, dampness, damage or gaps.

Exemptions to the insulation standard

There are three specific insulation exemptions. The information here is an overview. More information on these exemptions is available in Subpart 3 of the Healthy Homes Standards Regulations (external link) .

1. Access is impracticable or unsafe

Some areas of some homes may be unsafe or not reasonably practicable to access. This may be due to:

  • their design
  • limited access
  • potential for substantial damage
  • health and safety reasons.

There is an exemption for parts of homes where a professional installer is unable to access and/or insulate, until this becomes possible (for example when a property is re‑roofed). 

2. Partial exemption for certain underfloor insulation

If the rental home has existing underfloor insulation that was installed when the home was built or converted. This insulation must still be in reasonable condition. Landlords must have a copy of any compliance documents that shows the home met the requirements of the time. For example:

  • code compliance certificate
  • certificate of acceptance
  • another relevant compliance document.

3. Ceilings and floors with other habitable spaces directly above or below 
The third exemption applies to areas of ceilings or floors where there are other habitable spaces directly above or below. This might be another floor of the same property or another apartment. These areas do not require insulation to meet the healthy homes insulation standard.

These three exemptions are in addition to the general exemptions.

General exemptions to the healthy homes standards

Landlords who have installed new insulation since 1 July 2016 should already meet the healthy homes insulation standard. These landlords probably won’t need to do anything further to comply with the healthy homes standards. They should still check that the insulation is in a reasonable condition.

Some landlords didn’t need to improve their existing levels of insulation under the current requirements that came into force on 1 July 2019. These landlords may need to do so to meet the healthy homes standards.

Use our online tool to find out if you are likely to need to upgrade or replace your insulation to meet the healthy homes standard.

Online tool: Do you need to upgrade your insulation to meet the healthy homes standards?

Further information

The insulation standard is one of five healthy homes standards. Find out about the other healthy homes standards:

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