Working within a budget to make savings
April 30, 2026
When Katie moved to Killcare in June 2024, it was a conscious lifestyle choice. After spending most of
Insulation acts as a barrier to heat flow and is essential for keeping your home warm in winter and cool in summer. A well-insulated home provides year-round comfort, cutting cooling and heating bills, and reducing greenhouse gas emissions.
Most houses can add insulation to the ceilings, walls and floor to make them more comfortable and save on your energy bills.
| Location | National Building Code minimum R-value | Cost-effective (approx) R-value |
|---|---|---|
| Roof / ceiling | 4.1 to 5.1 | 6.0 |
| External wall | 2.8 | 3.0 |
| Suspended floor | 2.0 | 2.5 |
An insulation material’s ability to resist heat flow is measured by its R-value. The higher the R-value, the better the insulation.
Several factors determine the R-value, including the material type, thickness, and density.
Generally, it is good idea to go beyond the minimum recommended levels, however cost and practicality are important considerations. For reference, typical R-values for the Central Coast are shown in the table.
Insulation products come in 2 main types: bulk and reflective, which are sometimes combined.
All insulation sold in Australia must display the relevant R-value according to AS/NZS 4859 tested to AS1530 to determine their level of combustibility.
There is a wide range of insulation materials commonly available. These include:
Selecting the right insulation material and type for the job is important. Your Home website provides good information on the different types of insulation materials and how to use them.
In considering which insulation material to use, it is worth considering:
Some types of insulation should be installed by a professional, while some you can do yourself.
DIY works best for accessible roof spaces, where:
In all cases:
Certain materials and installation methods must be handled by professionals due to chemical complexities, specialised equipment requirements, and significant safety risks. These include:
If you wish to get a ‘no obligation’ quotation for insulation, use the link provided to find a reputable local installer.
Almost all existing houses can be better insulated, however some jobs are more complex and expensive than other. We suggest that you get an expert opinion from our partner installer who can tell you what is possible and give you a ‘no obligation’ quote.
Spring and Autumn are ideal times to install insulation, as roof spaces are not too hot and installation companies are most available.
Many insulation materials compress over time and become less effective, so it is worth ‘topping up’ ceiling insulation periodically – say every 5-8 years. Also, check that the insulation in the attic has not been moved, creating gaps that allow heat transfer. This often occurs as things are stored or moved within the attic space, or if new cables, lights or air conditioning has been installed in your house.
Note that for safety reasons, minimum manufacturer’s specified clearances must be left around hot objects, such as flues from fires, recessed halogen downlights and their transformers.
Usually it is possible to add to existing layers of insulation, so long as there is adequate space to allow for ventilation and taking care to follow the product specifications, to minimise the risk of condensation or fire.
If covering a layer of batts or rolls, it is a good idea to place the new insulation at 90o to the existing later to minimise air gaps.
This can happen if you are using your heating or cooling for longer or if your electricity or gas tariffs have increased. For example, the weather may be warmer or cooler compared to a previous period or you may be keeping your home at a different temperature, so that you are using more energy. Or you are actually using less energy but paying more for it because of price rises.
Correctly installed insulation should lead to warmer surfaces in winter and therefore less condensation on walls and ceilings. Mould tends to occur where moist air is trapped so great care should be taken to ensure adequate ventilation in roof spaces and using exhaust fans in bathroom/kitchen.
If your house is already damp and prone to a build-up of mould, installing insulation is usually not the solution and it is best to fix damp issues before adding insulation!
When Katie moved to Killcare in June 2024, it was a conscious lifestyle choice. After spending most of
“I could immediately tell the difference that roof insulation makes, even on the hottest days. By keeping my
“I can keep my home at a comfortable temperature on most days without resorting to using air conditioning.”