Rental properties must have ceiling and underfloor insulation that meets the requirements of the 2008 Building Code and is in a reasonable condition. Existing ceiling insulation installed before 1 July 2016 must be at least 120mm thick to meet the insulation standard.

Insulation stops heat escaping from the house. In general, the better insulated a rental home is, the more it will retain heat. This means it will usually cost less to heat the property, and the property will be drier and be less prone to mould.

Note: Ceiling and underfloor insulation is already compulsory in rental homes. Find out about the current insulation requirements for rental properties

All private rentals must comply 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 Housing New Zealand and registered Community Housing Providers must comply by 1 July 2023.

What is the required level for insulation?

Insulation requirements under the healthy homes standards (which align to the 2008 Building Code) 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.

Map of New Zealand climate zones

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

You can check the R-value of new insulation by checking the product packaging. For existing insulation, you can check the thickness yourself (existing ceiling insulation must be at least 120mm thick) or consult a professional insulation installer.

Insulation must be installed in accordance with NZS4246:2016 [PDF, 6 MB] and must be in a reasonable condition, with no mould, dampness, damage or gaps.

Exemptions to the insulation standard

There is one specific exemption to the insulation standard.  This exemption covers properties where it is not reasonably practicable to install insulation.

It is not reasonably practicable to install something if a professional installer can’t access the area without:

  • carrying out substantial building work, or
  • causing substantial damage to the property, or
  • creating greater risks to a person’s health and safety than is normally acceptable, or
  • it is otherwise not practicable for a professional installer to carry out the work.

This is 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 requirements of the 2008 Building Code, so they won’t need to do anything further to comply with the healthy homes standards. Landlords should still check that the insulation is in a reasonable condition.

Use our online tool to step you through whether or not you are likely to need to take action to comply with the insulation requirements under the healthy homes standards.

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

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

Further information

The insulation standard is one of five healthy homes standards.

Find out about the other healthy homes standards: