Home Insulation Guide


Want to reduce your power bill without losing your cool? Home insulation can be a cost-effective solution to keeping costs down – and your home comfortable all year round.

Home insulation resists heat flowing in and out of your house, helping keep your home cool in summer and also warm in winter. Insulation is installed in ceilings, walls and floors – and can substantially reduce your home’s heating and cooling costs. In fact, Sustainability Victoria says insulation can save a typical home 45% on electricity per year. In this article, Canstar Blue discusses some insulation basics, including what you need to know to get started.

Benefits of Home Insulation

Insulation has a myriad of benefits, which is largely why this practical home climate solution has become the standard for new households.

  • Improved comfort: Insulation balances your home’s temperature to a comfortable climate – not too hot or too cold.
  • Electricity savings: Home insulation reduces the strain on your air conditioner or heater by helping keep the cool or warm air in. This means your appliances use less electricity.
  • Noise dampening: Some types of insulation have properties that help soundproof your home.
  • Reduced carbon footprint: By using less electricity, you’re reducing your impact on the environment. Many insulation products are also mostly recyclable.
  • Safe: Home insulation must pass rigorous testing to ensure it is flame retardant and safe to breathe.

The only downside to insulation is the obvious installation cost – depending on the size of your home, type of insulation and whether you hire a professional, installing insulation can set you back several thousand dollars.

Types of Home Insulation

There are two key types of insulation – bulk insulation and reflective insulation. There is also spray foam insulation, though it’s less common for practical and cost reasons.

Bulk insulation

Bulk InsulationBulk insulation is by far the most common type of insulation and is available to buy through insulation specialists or your local hardware store. Bulk insulation works by trapping air inside millions of tiny bubbles which helps resist the flow of heat in and out of your home. It comes in rolls, boards and batts – a large rectangle of insulation. Bulk insulation is produced from a variety of materials such as glass wool, polyester, natural wool, cellulose fibre and recycled paper.

Reflective insulation

Reflective InsulationReflective insulation works by deflecting radiant heat, making it suitable for hot and sunny climates. It’s pretty much a layer of aluminium foil laminated onto paper or plastic. It can either be installed independently within walls or just below the roof, or it can be attached to bulk insulation for effective ‘hybrid insulation’.

Spray foam insulation

Spray Foam InsulationSpray foam insulation is a new and incredibly effective insulation solution. Spray foam insulation is applied by spraying a solution in the ceiling, floor or walls which bubbles into a thick layer of insulation. It generally has a higher R-value than traditional forms of insulation. It also resists moisture and won’t sag as quickly as bulk insulation. So what’s the downside? As you might have guessed, spray foam insulation is expensive. It is also more flammable than traditional insulation, so it must be installed by a professional.

Insulation R-values

R-Value is the measurement of insulation’s ability to resist heat flow. R-Value ranges from 1.5 to 7 and the higher the insulation’s R-Value, the better that product is at insulating your home. There are three types of R-Value to be mindful of:

  • ‘Up’ R-Value: Measures insulation’s resistance to heat flow out of the house. This is also called winter R-Value because you want a high Up R-Value in winter to keep the heat in.
  • ‘Down’ R-Value: Measures insulation’s resistance to heat flow in to the house. This is also called summer R-Value because you want a high Down R Value in summer to keep the heat out.
  • Total R-Value: A combination of the up and down R-Values. If you see a generic reference to R-Values, it’s likely referring to total R-Value.

The Building Code of Australia (BCA) has outlined energy efficiency provisions for new homes, requiring certain R-Values depending on your ‘climate zone’ mapped below.


A number of other factors play into the R-Value requirements, including building colour and elevation above sea level. Generally, climates that need to keep the heat in require higher R-Values. Insulation in Zones 1 and 2 typically require an R-Value of 3 or 4 while properties in zones 3 to 7 will require an R-Value of at least 5. Those in the freezing alpine areas of Australia require insulation with at least an R-Value of 6.

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How to Install Insulation

You are allowed to install insulation yourself in most states and territories, but be sure to check your local laws before you start. Of course, just because you can do it yourself, doesn’t mean you should. Installing insulation can be dangerous, particularly in the ceiling. Insulation must also be installed in accordance with the Building Code of Australia, including R-Value requirements and ensuring sufficient clearance between insulation and electronics.

It is fairly simple to install bulk insulation in the ceiling. It is more difficult to install reflective insulation or installing wall or floor insulation post-construction however, as you’ll probably need to tear up the house to do it. So if you don’t have ceiling insulation yet, or you’re looking at topping up bulk insulation that may have collapsed over time, here are the basic steps.

  • Step 1 – Before getting started, know what R-Value you need and map out the ceiling to calculate how much insulation is required to fully insulate the ceiling. Also measure the width between ceiling joists to determine the correct batt width.
  • Step 2 – Before heading into the roof, turn the power off at the switch box and make sure you have all the equipment you need. This includes goggles, a face mask, light clothes, a torch, gloves and an insulation stick. The ceiling is the hottest part of the house, so wait for a cool day before installing insulation.
  • Step 3 – When in the ceiling, unpack the insulation batts and gently bounce them to expand. Lay the batts between the joists, being careful not to cover wires and leaving spaces around electrical recesses like down lights. Use the insulation stick to make sure the batts fit snuggly between the joists and that it reaches all the corners.
  • Step 4 – To make sure you cover any gaps, apply an insulation roll over the top of the batts. Also glue some insulation to the back of the ceiling access hatch.

While installing insulation yourself is rewarding, it’s recommended to hire a trained professional. Not only can working in the ceiling be dangerous, a poorly done insulation will dramatically reduce its effectiveness.

Home Insulation Companies

Australians are spoiled for choice when it comes to home insulation. There are dozens of brands out there with each garnering its own following of fans who’ll swear by the product. The brand that’s right for your home is your decision, but here’s a few of the most popular to get you started.

Knauf Earthwool

Earthwool produces a range of roof, wall and floor bulk insulation batts, as well as acoustic wall batts for noise dampening. Its insulation is also available in rolls with a reflective coating, as well as a lightweight ‘ClimaFoam’. Earthwool is odourless, rot proof and is made from recycled glass.

Pink Batts

True to its name, Pink Batts produce pink insulation wall, floor and ceiling batts. It also has some soundproofing acoustic batts, as well as reflective roof and hybrid insulation. Pink Batts is made from 80% recycled materials and comes with a homeowner lifetime warranty.

Autex GreenStuff

Continuing with the creative names, GreenStuff bulk insulation is, well, green. It comes in ceiling wall and floor batts. It also has a variety of polyester and sound proofing wall solutions. GreenStuff is 100% polyester, is 100% itch free and contains practically no dust.

Bradford Insulation

Bradford bulk Insulation has R-Values up to 7 and is produced from 80% recycled material. It is available in rolls and batts for the floor, ceiling and walls. It also produces bulk and reflective hybrid insulation as well as hypoallergenic ceiling insulation for sensitive homeowners.


Kingspan specialise in reflective insulation, said to be most suitable for tin-roof houses and sheds. It also manufactures insulated plasterboards for in-built insulation. Other products include spacers, glare shield insulation and reflective insulation tape.

Should I install Insulation?

Thermostat Wooly Hat

If your home isn’t insulated and you use an air conditioner or heater, the unfortunate reality is that you’re wasting electricity.  Insulation can potentially save hundreds of dollars on your power bill which will most likely justify the cost of insulation over time. If you already have insulation, it’s worth checking it every year or so to make sure it’s not sagged or damaged as minor faults in your insulation can have an exponentially negative impact on its effectiveness.

If you’re concerned about the cost of cooling or heating your home, make sure your system is clean and running properly, or upgrade to a more efficient model if necessary. If you haven’t compared electricity plans in a while, it could also be the case that you’re paying too much for power to begin with. You can start comparing providers with Canstar Blue via the link below.

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