Installing insulation in residential buildings

Posted: 9 December 2016

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The New Zealand Standard for installing insulation in residential buildings has gone through a major revision. The new Standard is NZS 4246:2016 Energy efficiency – Installing bulk thermal insulation in residential buildings. This replaces NZS 4246:2006 Energy efficiency – Installing insulation in residential buildings.
Article relates to four topics: Design, Site, Carpentry, Foundations.

The Standard provides guidance for the correct installation of insulation products by any installer, including DIY installers, in order to achieve high-quality and safe insulation installations in buildings.

How has the Standard changed?

The Standard has been updated and extended, and now provides additional guidance on installing insulation:

  • in steel-framed installations
  • under concrete slabs on the ground
  • around downlights, particularly where there have been significant technology advances.

Additional diagrams, photos and figures have been included to provide easy-to-understand, step-by-step guidelines for installing insulation in new homes, and for the retrofit of insulation in existing residential buildings.

Products and applications covered:

  • loose-fill (such as wool, mineral wool or cellulose fibre) for insulating walls and ceilings
  • segments and blankets (such as polyester, wool or mineral wool) for insulating in walls, ceilings and floors
  • rigid sheet insulation (such as expanded or extruded polystyrene (EPS or XPS) and polyisocyanurate (PIR) for insulating walls, ceilings and floors)
  • semi-rigid insulation (such as wool, mineral wool, polyester) for insulating walls, ceilings and floors
  • pipe insulation (such as pre-formed tubular foam)
  • hot water cylinder wraps (such as wool, mineral wool or polyester blanket with cloth or foil-backing)
  • on-ground vapour barriers.

Ban on foil insulation (retrofit or replacement)

Foil insulation continues to be excluded from the scope of the revised Standard. A ban on retrofitting or replacing foil insulation in residential properties came into force on 1 July 2016 to reduce safety risks associated with installing this product.

Ban on installing or repairing foil insulation in residential buildings

Meeting everyone’s needs

Installing insulation correctly means it performs effectively and doesn’t compromise the durability of your building, or put the health and safety of installers and occupants at serious risk.

In addition, the Standard is cited in the Residential Tenancies (Smoke Alarms and Insulation) Regulations 2016. If you have rental properties it’s important you read and comply with the Standard when installing insulation in those properties.

Where to find the revised Standard

The revision of the Standard was commissioned by the Energy Efficiency and Conservation Authority. Remember, familiarising yourself with this Standard could be counted as skills maintenance where it is relevant in an elective sense.

Read the revision of the Standard on the Tenancy Services website


1. NZS 4246:2016 updated and extended NZS 4246:2006 to include the installation of insulation in concrete slabs on the ground, in steel-framed installations and where else?

a. Rental properties
b. Cars, trucks and trailers
c. Around downlights.

2. What has been banned and is outside the scope of NZS 4246:2016?

a. Concrete slab insulation
b. Foil insulation
c. The Residential Tenancies Act
d. Segmented and blanket products.

3. NZS 4246:2016 will guide you to?

a. Install insulation products correctly so they perform efficiently and are safe
b. Choose the right insulation product for your situation
c. Specify the correct amount of insulation for compliance
d. Drive your car safely.

Check the answers

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: