Check

Do you have ceiling insulation? Is it up to scratch? Use a stepladder to access your roof space via the ceiling hatch. Or get an insulation professional to do it for you – they often do it for free.

Need to sort it out?

  1. 1

    See if you can get a grant

    Warmer Kiwi Homes is a Government programme offering insulation and heating grants to low-income home owners.

    Find out more(external link)

  2. 2

    Call the professionals

    Get quotes from at least two trained installation installers. We recommend choosing an Insulation Association of New Zealand (IAONZ) member.

    IAONZ(external link)

  3. 3

    Install it yourself

    Everything you need to know is in the New Zealand Standard. It’s easy to follow – but there’s a lot to know if you want to do a good job. Take care to follow the health and safety advice in Appendix B.

    Insulation Standard(external link)

You’ve got insulation – what next?

  1. 1

    Check coverage

    You’ll need a top-up layer if it’s less than 12cm thick, doesn't cover the whole ceiling, has gaps in it or places where it’s squashed or tucked in.
  2. 2

    Check for damage

    Remove old insulation and start again with a new layer if it’s wet or damp in places, or it’s been damaged by rodents or birds. Fix holes in the roof for future protection.
  3. 3

    Check for safety

    There should be gaps between insulation and heat sources like older recessed downlights, chimneys, flues or extractor fans for fire safety. See Appendix A of the New Zealand Standard for details and pictures.

    Insulation Standard(external link)

Types of ceiling insulation

  • Blankets

    Comes in a roll and can cover ceiling joists so heat doesn’t escape through the timber. An easy option to top up existing insulation because you can just roll it over what’s there already.

  • Segments

    Big pieces of insulation that fit between ceiling joists and can be cut to size. This leaves the joist exposed – handy for moving through the ceiling space but means heat can be lost through the timber. Use a denser product to make up for it.

  • Loose-fill

    Insulation blown onto the can be a good option if access is difficult – but its safety and effectiveness depends on the quality of the material used as well as the installer's equipment and experience.

How much is enough?

The R-value is a measurement of insulation effectiveness - the higher the R-value, the better it prevents heat loss. There are minimum requirements for rental homes, new homes and alterations. Use them as a guide for retrofitting ceiling insulation into an existing home – but in all cases, go much higher if you can.

Tricky bits

Roofs with no ceiling space

Insulating a home with a skillion or flat roof, or a cathedral ceiling, is best done when reroofing or renovating. There are solutions but it’s a skilled job – getting it wrong can cause moisture problems. Ask a qualified builder or roofer for advice.

Downlight fittings

Some modern LED downlights can have insulation fitted over them, instead of having to leave a gap for fire prevention. Not only does this stop your warmth escaping – the super-efficient LEDs use less energy and can save lighting costs. Ask a lighting specialist or registered electrician for advice.