Installing insulation
To get the best benefits from your insulation, it is essential for it to be installed correctly. Poor installation - such as small gaps, folds or tucked-in areas - can reduce your insulation's performance by up to 50%.
Insulation must also be installed properly for safety reasons - for example, having the right clearances around downlights, chimneys and flues means that heat from these sources does not create a hazard.
EECA recommends getting your insulation installed by a professional to ensure it is done correctly and safely. But if you are considering doing it yourself, here are some things you need to know.
Tips for safe, good-quality insulation installation
Follow the Standard for installing insulation
Standards New Zealand has produced a national Standard on how to install insulation in residential buildings. It provides comprehensive instructions on the best and safest ways to install insulation to ensure that it works as efficiently as possible. Download Standard NZS 4246:2006 : The NZ Standard in Energy efficiency - Installing insulation in residential buildings.
Follow safety practices
Installing insulation can be dangerous with potential risks including electrocution and sharp objects. It's very important to follow safe work practices when installing insulation products, especially with underfloor or ceiling insulation.
Standards New Zealand has published a standard on installing insulation. Follow the safety instructions described in Appendix B to Standard NZS 4246:2006 .
Make sure your ceiling space is dry
Before you install any insulation in your celing, check that it's dry (i.e. there are no leaks) and free of contaminents and mould. Remove any existing insulation that is damp.
Leave a gap between insulation and heat sources like downlights, chimneys and flues
Incandescent and halogen bulbs are the most common types used in downlights and these get very hot. You need to leave a clearance of 150 mm between the light fitting and the insulation, and never place insulation over the top of any downlight or auxilary equipment associated with the light.
Chimneys and flues can also get very hot. Leave a gap of 50 mm between the outer face of a brick or concrete chimney and the insulation, or a 150 mm gap for metal chimneys and flues.
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.
Getting professional advice
Getting professional advice can help you get the right insulation solution for you, installed properly and safely.
- Consult a builder or visit a hardware shop that sells insulation products
- Use our supplier and partners directory
- Get a professional report of your home's insulation requirements with a Home Energy Rating.
More information
- Standard NZS 4246:2006 - The NZ Standard in Energy efficiency - Installing insulation in residential buildings.
- Another useful guide to installing insulation is the Department of Building and Housing's Guide to Smarter Insulation.
- 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.








