If you're building a new home or renovating an existing one, don't forget about insulation. It's the material that is used to control heat transfer - so you're cool in summer and warm in winter. We've broken insulation down into the elements you will need to consider when selecting your insulation and the pros and cons of each type.
The performance of insulation is measured by its R-value. A high R-value means greater resistance to heat flow into the building in summer and out of the building in winter - in other words, the higher the R-value, the more effective the product. Recommended R-value's differ across Australia depending on climate, with highest being four and lowest being one. The recommended R-value of a ceiling is usually double that of the walls. Tip: Just because one insulation type is thicker than another, doesn't mean the R-value is greater.
The cost of insulation can vary greatly. Retro-fitting insulation into an existing home can be costly - the best times to install are during renovation or during the initial build. The higher the R-value the higher the initial cost but you'll save on energy bills down the track, good insulation can reduce your energy bills by as much as 55 per cent.
Climate / location
Where you live will determine what type of insulation you choose. The Building Code of Australia has set out minimum insulation requirements for eight climate zones within Australia. For example homes in Western Sydney require roof insulation with a minimum R-value of 3.2 in winter. Those in Cairns need only an R-value of 2.2 in summer. Your insulation supplier will be able to tell you which zone you live in.
Ensure your product comes with flammability test certificates. And, some insulation types such as rockwool and fibreglass can cause irritation to skin, eyes and nose so protective clothing must be worn during installation.
Thermal versus acoustic
Insulation is used to control sound as well as temperature. Unlike thermal insulation, the thicker and denser it is, the more soundproof it will be.
TYPES OF INSULATION
There are two main types of insulation; some people use a combination of both.
Bulk insulation works as a physical barrier to the flow of heat. Types include cellulose fibre, sheep wool, polyester, glasswool and rockwool.
Very effective in cooler climates
Can double well as acoustic insulation
Will lose effectiveness when damp
Irritation to skin, nose and eyes can occur when installing some types
As the name suggests, reflective insulation works by reflecting heat away with its polished metallic surface. Types include aluminium foil sarking, foil boards, E-therm and foil batts.
Very effective in warmer climates
Acts as barrier to moisture
Takes up less room than bulk insulation
Needs to be combined with bulk insulation to be effective during winter in cooler climates
Dust can settle on its surface, reducing effectiveness