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

What insulation to install

1) If insulation was installed in your rental property before July 2016 an upgrade may not be necessary provided the ceiling and underfloor insulation:

  1. is in reasonable condition (e.g. no mould, dampness or gaps in the insulation), AND

  2. achieved at least the minimum R value when the insulation was originally installed

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

Over time, some insulation is known to settle.  Provided the above criteria apply and the insulation hasn’t settled below 70mm thick, you shouldn’t need to retrofit insulation.

Please read regulations 13, 15 and 17 of Residential Tenancies (Smoke Alarms and Insulation) Regulations 2016(external link) for further clarification.

If any part of the existing insulation is not in reasonable condition, then the landlord must install insulation that meets the new standard required from 1 July 2016. Insulation installed before 1 July 2016 that is not in a reasonable condition cannot be repaired; it must be replaced with insulation that meets the new standard.

2) If ceiling and underfloor insulation was installed at your rental property after 1 July 2016 OR you don’t have any, you need to ensure the insulation meets the minimum new and topped up levels of insulation before 1 July 2019. It needs to meet these minimum R-values:

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

If a rental property is below these levels of insulation, it must be upgraded.

rta map zones

If the rental property currently has insulation and it is not in a reasonable condition, then you must repair or replace the insulation (or part of) to meet the new standard. Where there are multiple layers of insulation and all layers are in reasonable condition, then their product R-values may be combined.

For further information you can read Tenancy Services’ Insulation Requirement Guide below.

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

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.

Building design exceptions

Due to the design or construction constraints of some property types, it is sometimes either not physically possible to insulate or would require major renovations to do so.

Examples of types of properties that would meet exception criteria would be apartments where there is a habitable space above and below the apartment, houses constructed on concrete slabs where it is not feasible to install underfloor insulation, and homes with skillion roofs where there is no ceiling in place to install insulation above.

Access exceptions – what’s acceptable and what’s not

In many properties the most common way to access the ceiling space or underfloor to retrofit insulation would be through an existing trapdoor to the ceiling or an external door to crawl under the house.

Retrofitting insulation is not considered ‘reasonably practicable’ when an experienced professional insulation installer;

  • cannot access the location to install insulation without removing any cladding or lining, carrying out other substantial building work, or causing substantial damage to the property. 
  • cannot install insulation without creating health or safety risks to people, that are greater than the level of risk normally acceptable when insulation is being installed.

Where access to the ceiling or underfloor can be achieved by carrying out minor work (e.g.: temporarily removing base boards from the exterior of the property to access the underfloor), the landlord is expected to do so. The need for building work to be undertaken in order for insulation to be installed by an experienced professional does not satisfy criteria for an exception, unless substantial building work would be required, or substantial damage would be caused to the property. Any building work carried out must comply with the building code.

If the reason a property was excepted from complying with insulation requirements changes – for example a new roof is installed that allows room for insulation – then a landlord must ensure that insulation is installed as soon as is reasonably practicable.

If a landlord is in any doubt whether insulation can be installed in their rental property, they should consult an experienced professional insulation installer and, if needed, a builder. If the experienced professional says insulating some areas is not reasonably practicable or not possible, the landlord should ask for written confirmation of the reasons to include in tenancy agreements.

It is not adequate for a landlord to simply claim that ‘insulation is not reasonably practicable’. Failure to comply with insulation obligations under the new legislation could attract a penalty of $4000 for income-related rent landlords. For all other landlords this penalty applies from July 2019.

Other exceptions to insulation requirements

Other situations in which rental properties may be excepted from the insulation requirements are:

  • Where within 12 months of the start of a tenancy, the landlord intends to demolish or substantially rebuild all or part of the property. In this case the landlord must, if requested, provide evidence of having applied for the necessary resource consent and/or building consent for the redevelopment or building work.
  • Where a property is purchased from and immediately rented back to the former owner-occupier – in which case a 12 month exception will apply from the date of purchase.
  • If a property does not meet the new insulation requirements, but a landlord can provide evidence that when insulation was originally installed it did comply with particular insulation requirements (such as the specifications outlined in the building consent or an Acceptable Solution or Verification Method) the property is excluded from new requirements, provided the insulation is in reasonable condition.