Installing insulation
To get the best benefits from your insulation, it is essential for it to be installed correctly. Poor installation can reduce your insulation's performance significantly or even create a safety hazard - so make sure it's done once and done well.
Professional or DIY installation?
EECA recommends using a qualified professional - but here are some things to consider with each approach.
| PROFESSIONAL | DIY | |
| Pros | Get recommendations on the right insulation solution for your home. A quality, professional installation will ensure the |
DIY installed cost is cheaper
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| Cons | Professional installed cost is usually a bit higher than DIY - though often not by much. Find out what people are paying for professionally installed insulation under Warm Up New Zealand: Heat Smart. |
It can be tricky and time- consuming to install the insulation properly and safely. |
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If you |
Check out the funding programme for ceiling and underfloor insulation - all installations under this programme are required to meet strict quality and safety requirements. Otherwise, look for an installer that follows the |
Follow the advice below
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Tips for safe, quality DIY insulation installation
If you opt for DIY insulation installation, here are some important things you need to know - bear in mind EECA cannot cover every situation that may arise.
Follow the national standard for installing home insulation
A national standard has been produced to provide clear, comprehensive guidance on installing home insulation correctly and safely. The standard is widely used by insulation professionals, and is strongly recommended to DIY installers.
>> Download the Standard NZS 4246:2006 Installing insulation in residential buildings.
Follow safety practices
There are a range of safety considerations when installing insulation and following safe work practices is very important. Comprehensive information on protective equipment and safety precautions can be found in Appendix B of the national standard for installing insulation, described above.
Check the product manufacturer's instructions
Ensure that you follow the manufacturer's instructions for the specific insulation product you're using.
Fit your insulation properly
Insulation that's not fitted properly will not perform as well as it should. Ensure there are no gaps between insulation pieces, and that there are no tucks or folds. Use off-cuts to fill any small gaps.
Make sure your ceiling space is dry
Before you install any insulation in your ceiling, check that it's dry (i.e. there are no leaks) and free of contaminants and mould. Remove any existing insulation that is damp.
Leave the right clearances around ceiling heat sources
For fire safety reasons, insulation should not be installed too close to ceiling heat sources - like recessed down lights, chimneys, flues or extractor fans.
>> Learn about safety gap sizes around ceiling heat sources.
Take care with underfloor electrics
Electrical safety is crucial when checking, replacing or installing underfloor insulation - for example, taking care not to staple near electrical cables, special care with foil insulation, and preventing contact between polystyrene insulation and PVC-coated electrical cables.
>> Learn about safety considerations with underfloor electrics.
It's easier to install with two or three people
It's easier to install insulation with two to three people - even professional installers usually work in a team. Although it is possible to do it by yourself, it will be harder to get the quality of installation that you need for your insulation to work as well as possible.
Building consents
Retrofitting wall insulation requires a building consent unless your local council has granted an exemption for this type of work. A building consent is not required for the retrofitting of ceiling and underfloor insulation in existing buildings.
Either way, the work must comply with the Building Code.
>> Find out about requirements through your local council.
More information
- The New Zealand Building Code specifies minimum mandatory insulation standards for new houses. Check with the Department of Building and Housing website for changes to the Building Code.









