A Beginners Guide to Home Insulation

Understanding the importance of home insulation and its various advantages can help you make informed decisions about improving your home's energy efficiency and comfort levels. Proper insulation can significantly reduce energy waste leading to reduced consumption and lower utility bills. Ever tried heating a drafty room? – it’s difficult and takes a lot more energy. Insulation also helps create a more comfortable living environment with a consistent temperature. Insulation can be placed in your home’s walls, roofing or floor. We’ve compiled the information below to provide the basics of home insulation. If you are looking to install insulation at home, it’s important to conduct your own research and discuss your needs with a certified provider.


What is insulation?

Insulation refers to materials or techniques used to reduce heat transfer between the interior and exterior of a building. It involves adding a layer of insulation to walls, floors, roofs, and other parts of a house to create a thermal barrier.

Insulation works by slowing down the flow of heat from warmer areas to cooler areas. In winter, it helps retain the heat generated by the heating system inside the house, while in summer, it prevents the outside heat from infiltrating the interior. By effectively controlling the transfer of heat, insulation is commonly used to maintain a comfortable indoor temperature while minimising the need for heating and cooling systems that can consume more energy.

Your local climate and how your home has (or will be) built can influence the type of insulation you need. For example, the right insulation will vary between suspended floors, timber floors and concrete slabs, or weatherboard walls, brick veneer walls, and solid walls.


Different types of insulation

There are three categories of insulation: bulk, reflective and composite (which is a combination of bulk and reflective).

Bulk Insulation

Bulk insulation is a material designed to work by trapping pockets of air within its fibres, which slows down the transfer of heat through convection. Bulk insulation materials come in various forms, some of which are listed below.

Glass wool









  • Comprised of glass wool fibres that capture air, minimising the transfer of heat.
  • Comes in the form of precut batts and rolls.
  • Commonly used in walls, ceilings, and floors.
  • Can be made from recycled materials.











  • Made from sheep wool, it can be bound by an adhesive or mechanically.
  • Comes in batts and loose fill. 
  • Often used in walls and roofs.
  • Has fire resistance properties and is also resistant to pests, mould, and mildew, so is often used in areas where moisture and fire protection are important.


Cellulose fibre

  • Can be made from recycled fibres from plants or paper.
  • Treated to minimise combustion.
  • Can be made from recycled materials.
  • Loose fill nature of this type of insulation means it can be used in attics, walls, and floors. As its blown into these spaces, it can fill gaps and cavities effectively.
  • Known for its excellent soundproofing qualities.











  • Made from Polyethylene Terephthalate (PET).
  • Comes in batts or rolls.
  • Can be made from recycled materials. 
  • Good for sound proofing.



  • Two types: expanded polystyrene (EPS) and extruded polystyrene (XPS).
  • EPS - lightweight and has excellent insulation properties. It is commonly used in walls, roofs, and under concrete slabs.
  • Extruded polystyrene (XPS) XPS is denser and offers higher moisture resistance, making it suitable for below-grade applications like basements and foundations.
  • Has a higher environmental impact as it take hundreds of years to decompose.


Natural Fibre Insulation

  • Materials such as cotton, sheep's wool, hemp, cellulose, and straw bale can be used as insulation.
  • These natural fibres are renewable, sustainable, and have good insulation properties.
  • Natural fibre insulation is often found in environmentally friendly or allergy-sensitive applications.


Reflective Insulation

Reflective insulation is a material that works by reflecting radiant heat away from a surface rather than slowing down its transfer through conduction or convection. It achieves its insulating properties by creating an air gap of at least 25mm next to a shiny surface. The effectiveness of the insulation can vary depending on the direction of heat flow through it.

Reflective insulation typically consists of shiny aluminium foil laminated onto paper, plastic or foam, and is available in different forms such as sheets (sarking), concertina-type batts, and multi-cell batts. These products are collectively known as reflective foil laminates (RFL).

Reflective insulation is often used in attics, roofs, and walls to reduce radiant heat gain and is particularly useful for reducing summer heat buildup and improving energy efficiency in warm regions.

You will need to monitor reflective insulation for dust and dirt as it can decrease its efficiency in reflecting heat away from the surface.


Composite insulation

Composite insulation is a material that combines two or more types of insulating materials (e.g., bulk and reflective) to achieve a specific level of thermal performance.

It typically consists of multiple layers, with one or more layers of bulk insulation and a reflective layer. The bulk insulation provides resistance to conductive and convective heat transfer, while the reflective layer acts as a radiant barrier. This combination maximises the insulation's overall effectiveness in reducing all three types of heat transfer: conduction, convection, and radiation.

As such, composite insulation can offer advantages over single-material insulation products by providing enhanced thermal performance, improved moisture resistance, and reduced sound transmission. However, composite insulation can be more expensive and difficult to install than single-material options.


How is the efficiency of each insulation type measured?

The efficiency of insulation is typically measured by its R-value, which indicates its ability to resist heat flow. A higher R-value indicates more effective insulation and greater energy efficiency. To learn more about R values please read the Australian Government’s YourHome information on insulation. Your insulation provider should be able to provide more guidance too.


How is home insulation energy efficient?

Home insulation can significantly improve energy efficiency by reducing the heat lost or gained through the walls, ceiling, and floor. By adding insulation, your home's interior is better protected from outdoor temperatures, resulting in less need to use heating or cooling systems or appliances that increase energy consumption.


What are other benefits on home insulation?

  • Energy efficiency and cost savings
    One of the main benefits of home insulation is its ability to enhance energy efficiency. By minimising heat loss during winter and heat gain during summer, insulation helps stabilise indoor temperatures, reducing the need for excessive heating or cooling. This results in lower energy consumption and cost savings on heating and cooling bills.
  • Increased thermal comfort
    Insulation can provide a consistent indoor temperature throughout the year by reducing draughts, heat transfer, and temperature fluctuations within your home.
  • Sound proofing
    Some insulation can reduce noise or sound proof areas of your home.
  • Environmental impact
    Some insulation materials such as fibreglass, fibreglass wool, cellulose fibre and polyester can be made from recycled materials.
  • Minimises condensation
    Insulation also helps control moisture and condensation. By reducing temperature differentials between indoor and outdoor surfaces, it limits the formation of condensation, which can lead to mould, mildew, and structural damage.


What are some other things to consider before installing home insulation?

When researching the best home insulation type for your home ask your certified provider about:

Life span
The following things may be a sign that the quality of your insulation’s efficiency is beginning to wane:

  • Changes to indoor temperature – your home may be warmer in summer and cooler in winter.
  • Increase in energy bills from using appliances to make up for the lack of the insulation’s efficiency.
  • Heavy rain causing water damage to your roof.
  • Pest infestation.

It may be hard to maintain the insulation itself but monitor the following to ensure its in the best condition and position:

  • Insulation fastening – if it’s not fastened properly and moves out of place, air pockets can be formed causing draughts.
  • Water damage – this can lead to damage to insulation along with mould growth. You may need to remove the insulation, fix any holes where water is leaking through and replace the insulation.
  • Pest infestation – bugs and rodents can destroy insulation or create moisture issues.

Roofs and walls can contain electrical wiring. Before installing insulation, arrange for a licensed electrician to inspect your wiring. Old wiring may not be able to accompany insulation as it can overheat the wiring and potentially cause a fire. It is recommended you turn off your electricity at the switch box prior to an electrician’s inspection AND when installing insulation. The Victorian State Government has some useful information on how to install insulation safely.


You may be eligible for a Green Home Loan

By making your home more energy efficient and reducing its impact on the environment you may qualify for a discounted Green Home Loan.

Our award-winning Green Home Loan product rewards members who want to adopt a more sustainable lifestyle with a discounted interest rate.