Insulation
Insulating your house will save you $100 a year in heating and cooling costs, and will save up to a tonne of greenhouse gas emissions. Insulated homes are also naturally warmer in winter and cooler in summer, so they’re more comfortable to live in.
When choosing insulation, the most important factor to consider is its R-value. The R-value is a measure of the material's resistance to heat flow, and therefore its performance. The higher the R value, the greater the resistance to heat transfer, and the greater the energy savings.
Australian Standards recommend different insulation levels for different locations based on climatic differences as well as energy and insulation costs.
Rebate
In NSW, a rebate to cover half the cost of installing ceiling insulation in your home, up to a maximum of $300 is available through the NSW Climate Change Fund.
Types of insulation
Bulk insulation
Bulk insulation works by reducing the amount of heat that transfers through a roof, wall or floor, in the same way as a jumper keeps you warm. Like a jumper, bulk insulation is full of holes, or air pockets; these air pockets trap heat.
For this reason, it is important that bulk insulation is not compressed. Compressing the insulation reduces the volume of air and therefore reduces the ability of the material to resist heat transfer.
Examples of bulk insulation include batts and loose fill insulation.
Reflective insulation
Reflective insulation works by reflecting large amounts of heat away from its polished metallic surface. Note that reflective insulation must face a sealed airspace at least 25 mm wide.
Reflective foil is often supplied in rolls however other examples include concertina foil batts and multi-cell reflective batts.
As reflective foils have different R-values (the measure of insulation performance) in winter and summer, make sure winter R-value meets the requirements for your locality.
Tips
- Make sure corners of ceilings, walls and floors are properly insulated - this is often where heat leaks are found.
- Draught-proof your home. In winter, your heating costs can increase by up to 25% because of draughts. Check doors, windows, fireplaces, air outlets, vents and skirting boards for gaps and choose from the wide range of draught-proofing products to seal areas.
- Avoid gaps in the insulation. Even if only 5% of the area is left uninsulated, up to 50% of the potential benefits may be lost.
- Have your wiring inspected by an electrician to ensure it can be safely covered by insulation.
- Caution! Do not install insulation within 90mm of hot flues or exhaust fans.
- Do not put insulation over or around recessed light fittings - leave a 25 mm gap around their perimeters.
- Good insulation should be coupled with effective window shading and ventilation in summer to avoid trapping heat inside the home.
- Insulate hot water pipes, especially the first two metres leading from the hot water system. Closed cell rubber insulation is recommended.
- Reflective foil installed under the roof (sarking) will reflect large amounts of direct radiation away from the home in summer.
- Bulk insulation materials have good soundproofing qualities. A building blanket installed directly under metal roofing helps to reduce noise resulting from wind, rain and hail. If soundproofing is desired between rooms, high density insulation can be installed in internal walls.