Insulation will be compulsory in all rental homes from 1 July 2019.

Ceiling and underfloor insulation must be installed, where it is reasonably practicable to install. It must comply with the regulations and be safely installed. Wall insulation is not compulsory.

Any new, replacement or top-up insulation installed after 1 July 2016 in a rental home must meet the regulations that will apply to all rental homes from 1 July 2019.

A landlord who fails to comply with the regulations is committing an unlawful act and may be liable for a penalty of up to $4,000.

Safety warning

The installation or repair of electrically-conductive insulation, known as foil insulation, is banned in all residences including rental homes. Anyone who breaches the ban commits an offence and may be liable to a penalty of up to $200,000.

Safety warningDo not touch foil insulation without turning off the power at the mains first as there is an electrocution risk. If you have any doubts, contact a qualified electrician. If you choose to remove foil insulation, hire a qualified professional.

Anyone who inspects foil insulation even after turning off the power at the mains must proceed with caution as in some instances the foil may still be live – check Worksafe’s Electrical Code of Practice 55.

Landlords can install insulation themselves. However if you are not certain you can meet all the regulations including safety rules, you are strongly advised to contact a qualified professional insulation installer. There can be serious safety risks to both landlord and tenant if it’s not done properly.

Insulation safety covers the how to, legal and safety risks for checking and installing insulation.

The insulation regulations apply to any residential rental covered by the Residential Tenancies Act including rental homes and boarding houses. They will apply to sleep-outs depending on the design.

A landlord has the right to enter a rental home to comply with insulation requirements after 24 hours’ notice, and between the hours of 8 am and 7 pm.

Insulation has been compulsory in all social housing where the tenant pays an income-related rent since 1 July 2016. If the tenancy began on or after that date, the landlord has 90 days to meet the regulations.

Read the new Residential Tenancies (Smoke Alarms and Insulation) Regulations 2016 (external link)

What insulation to install

If the rental home is already insulated, and the insulation is in reasonable condition

The ceiling and underfloor insulation must be upgraded to the R-value levels set out in the table below.

Minimum new and topped up insulation requirements for rented homes (product R-values)

Zone 1 and 2Zone 3
Ceiling R 2.9 Ceiling R 3.3
Underfloor R 1.3 Underfloor R 1.3

If there is no insulation, or the insulation is not in reasonable condition.

The ceiling and underfloor insulation must be upgraded if it does not meet the thermal resistance or R-value levels set out in the table below.

Level of insulation below which rental properties must be upgraded (product R-values)

Timber-framed minimumMasonry minimum
Ceiling R 1.9 Ceiling R 1.5
Underfloor R 0.9 Underfloor R 0.9

Map of climate zones

The map below illustrates the Building Code climate zones that the table above refers to, with Zone 1 being the warmest areas and Zone 3 the coldest.

rta map zones

Topping up existing insulation

Insulation that falls below the minimum requirements of the regulations will need to be topped up or replaced. Landlords should consider consulting a qualified professional insulation installer for the best way to meet the regulations.

EECA Energywise has advice on choosing an insulation installer (external link)

Meeting the New Zealand Standard

Whoever is installing the insulation must do it in accordance with New Zealand Standard NZS 4246:2016.

This gives guidance on the correct way to install insulation in an effective and safe way. It explains how anyone installing insulation should keep themselves safe and what safety clearances are required from downlights, chimney flues, roofing etc.

Download the New Zealand Standard NZS 4246:2016 Energy efficiency – Installing bulk thermal insulation in residential buildings [PDF, 6 MB]

Copyright in NZS 4246:2016 is held by the New Zealand Standards Executive. Standards New Zealand on behalf of the New Zealand Standards Executive has given permission to the Ministry of Business, Innovation and Employment (Tenancy Services) to provide access to the standard under copyright licence LN001211. The reader is permitted to view and print the 2016 edition of the standard free of charge (subject to printing costs) for your own use. You are not permitted to reproduce any part of it without prior written permission from Standards New Zealand unless your actions are covered by Part 3 of the Copyright Act 1994. (external link)

For queries about copyright please contact Standards New Zealand at copyright@standards.govt.nz.

Insulation costs

As a rough guide, the average cost of paying a professional installer to put in both ceiling and floor insulation is approximately $3,400 excluding GST for a 96m2 property.

Before choosing the product, check the cost per square metre of products with better performance – these have a higher thermal resistance or R-value. The prices of lower and higher-performing insulation products are often similar.

Landlords are responsible for the costs of insulating their rental homes. If a landlord increases the rent they must comply with the requirements in the Residential Tenancies Act.

Increasing rent has more on when and by how much landlords can increase rent.

Rental homes excluded from the regulations

A rental home is excluded from the insulation requirements in the regulations:

1. Where it is not reasonably practicable to install insulation because of the physical design or construction of the property.

This applies only until such time as access to these spaces becomes possible.
Where a landlord wishes to install insulation themselves but is unable to do so, they are expected to hire someone to do it on their behalf.

The installation of insulation is not considered reasonably practicable where:

  • an experienced professional insulation installer cannot access the location to install the insulation without removing any cladding or lining, carrying out other substantial building work, or causing substantial damage to the property
  • an experienced professional insulation installer cannot install the insulation without creating risks to the health or safety of any person that are greater than the risks that are normally acceptable when insulation is being installed by an experienced professional
  • it is otherwise not reasonably practicable for an experienced professional insulation installer to install the insulation at the location.

2. Where, within 12 months of the start of a tenancy, the landlord intends to demolish or substantially rebuild all or part of the property, and can provide evidence of having applied for the necessary resource consent and/or building consent for the redevelopment or building work.

3. Where a property is purchased and immediately rented back to the former owner-occupier – in which case a 12 month exception will apply from the date of purchase.

4. If a property does not meet the insulation requirements, but a landlord can provide evidence that when insulation was originally installed it complied with particular insulation requirements, for example an Acceptable or Alternative Solution, or was approved under the Verification Method, then it is excluded from requirements provided that the insulation is in reasonable condition.

Acceptable Solutions and Verification Methods (external link)

5. Where the habitable space of another unit, for instance an apartment, is directly above or below a ceiling or floor, this area does not need to be insulated.