About insulation
The following provides a brief explanation about heat loss in the home and how insulation can help make your home easier and cheaper to heat. A variety of products are available on the market so it is important to understand which products meet quality standards.
On this page
- Heat loss in the home
- How insulation works
- Types of products
- Product labelling
- Safe practice
- Take action
Heat loss in the home
Heat is lost from the inside of the house in three ways:
- directly through the walls, ceilings, windows and doors
- through any cracks
- through unblocked chimneys
- through windows and skylights.
How insulation works
Insulation works by slowing the rate of heat flow through ceilings, walls, floors, windows, etc.
Benefits of insulation
Good quality insulation offers these benefits:
- a significant reduction in the rate of heat loss though ceilings, walls, floors
- this in turn makes the house easier and cheaper to heat
- which, if the heating is done properly, makes the house healthier and more comfortable to live in.
Types of insulation products
Insulation can be made from fibreglass, polyester, wool or other loose fill products, and can be used in different forms such as:
- biscuit – pre-cut pieces
- blanket – long rolls
- loose fill – where loose material is pumped in.
The Energy Efficiency and Conservation Authority (EECA) does not recommend the use of loose fill products due to the potential for the insulation to shift and settle over time reducing its R value and effectiveness.
Use quality insulation products
Well-made insulation is more likely to do its job and remain effective for years to come. Insulation can be bought at most hardware shops, or from specialist insulation suppliers.
Check your phone directory for a company near you or go to our ‘Find an expert’ listed under Seek professional advice.
Building Code standard
For a copy of ‘The Building Code Compliance Document Clause H1 Energy’ go to Download free PDFs of the Compliance Documents. [Department of Building and Housing website.]
For levels beyond Code, you could refer people to the 'Best' level in SNZ PAS 4244:2003 Insulation of Lightweight-framed and Solid-timber Houses.
Product labelling
AS/NZS 4859.1 standard
If the insulation has been tested to this standard there will be a compliance statement on the label. Look for the AS/NZS 4859.1 standard: ‘Materials for the thermal insulation of buildings. Part 1: General criteria and technical provisions’.
The Energy Efficiency and Conservation Authority (EECA) recommend products tested to this standard.
R value
The effectiveness of insulation is measured by its R value. The higher the R value on an insulation product, the more it slows down the transfer of heat. The R value of insulation gets higher as the product gets thicker.
For example an R3.0 product provides more insulation than a R1.0 product.
(Note: Reflective foils do not have an R value. But the foil helps increase the R value of your floor by trapping air between the floor joists.)
Safe practice
Make sure you follow safe work practices when installing insulation products, especially underfloor or ceiling insulation.
Follow the safety instruction listed under these topics.
Installing standard NZS4246:2006
Standards New Zealand has published a standard on installing insulation (NZS4246:2006) (PDF, 2.9MB).
Take action
1. Find out your home insulation needs
- Work your way through each of the following topic areas to find out how to insulate to make your home easier and cheaper to insulate:
2. Prioritise areas to insulate
- Identify which areas of your home need insulation. Priority areas to check are: in the roof, underfloor, windows.
- Check also for dampness or moisture under the house.
- Also inspect your home for draughts using the checklist and suggestions in the section on Air leakage and draughts
3. Apply for an insulation grant
- If you are on a landlord, low-income homeowner or tenant, find out if you will qualify for a home insulation grant.
- Consult a builder or visit a hardware shop that sells insulation products.
- Use our Energy services directory Find an expert.
- Get a professional report of your home’s insulation requirements with a Home energy rating assessment
- It is very important to follow basic safety guidelines when installing insulation products. For full instructions on how to install various types of insulation and the appropriate safety requirements download a copy of NZS4246:2006.