Insulation and draught proofing

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Insulation and draught proofing can prevent excessive heat gain in summer and heat loss in winter. This can reduce the energy required to keep your home comfortable, leading to lower energy bills.

Insulation

Installing appropriate insulation in the roof, walls and floors could save over 50% on your heating and cooling costs.

The appropriate type and amount of insulation depends on your climate, style of home, and whether extra heating and cooling is used. Ask an insulation retailer or installer to find out which insulation type is right for your home.

There are several types of insulation commonly available. Each is suited to different purposes and areas of the home. Some of these are listed below.

Bulk insulation works by trapping air in still layers to resist the movement of heat. It’s made from materials such as fibreglass, polyester and natural wool, and comes in batts, rolls, loose fill or foam boards.
- Spray polyurethane foam (SPF), a type of bulk insulation, is created on-site by mixing and spraying chemicals that react and form a foam. It can be used to insulate many areas and is particularly helpful with sealing cracks and gaps effectively.
Reflective insulation typically consists of aluminium foil laminated onto paper or plastic. It reflects heat in the direction the foil faces. When the foil faces away from a home, reflective insulation can help keep heat out. With the foil facing inward, it can help reflect heat back into a home.
Composite insulation combines bulk and reflective insulation, for example foil-faced boards, reflective foil-faced blankets and foil-backed batts.

Eco-friendly options are also available. Ask a professional installer or manufacturer about insulation made from recycled materials.

Installation

If you’re planning to install insulation yourself, make sure you can do it safely. If you’re uncertain about any part of the process, contact a professional. All insulation work must meet the requirements of the National Construction Code and relevant Australian Standards.

If you plan to hire someone to install insulation, make sure you use an appropriately trained and certified installer to ensure your insulation is installed safely and effectively. Poor installation can significantly reduce a product’s performance.

The Energy Efficiency Council has a directory to help you find a certified expert.

Before starting the installation:

Get a licensed electrician to check your wiring to confirm it is safe to cover with insulation.
Ask about the required safety clearances around light fittings, transformers, exhaust fans, bathroom heaters, and other sources of heat.

If your insulation is old, check if it needs replacing.

Find out more about your insulation options on Your Home.

Draught proofing

Draughts introduce unwanted outdoor air into a home. By blocking draughts, you can minimise heat loss in winter and warm air entering in summer. Sealing gaps around the house is a simple, affordable way to do this – and it may reduce heat loss by 15% to 25% (CSIRO 2015).

Look for obvious gaps around:

windows and skylights
floorboards and skirting boards
walls
doors
vents and exhaust fans
appliances that connect to walls
fireplaces.

To check for other gaps you can try holding a lit incense stick near doors and windows and watch the smoke to see which direction it blows and how quickly it moves.

Rattling or whistling sounds during windy weather, moving curtains or feeling a breeze are also signs of gaps. Alternatively, you can hire a professional to perform an air-leakage analysis on your home.

Consider these tips to seal gaps and draught-proof your home:

Install draught stoppers or door snakes at the base of doors.
Apply foam strips around window frames.
Use sealant, expanding foam, or gap filler around skirting boards, architraves or window frames (always check the manufacturer’s label for instructions).
Fit draught seals to the base and frames of internal and external doors.
Cover exhaust fans that vent into the roof with backflow-preventing draught stoppers.
Use vent covers to block evaporative cooler vents during the colder months when heating is in use.
Seal any unnecessary wall vents – unless you use unflued gas heaters, which require ventilation.
Use window coverings to prevent air from gaining or losing heat via the window surface.

Ventilation

Ventilation allows outdoor air into a building on purpose. Ventilation can be:

natural by allowing air to move through openings like windows and doors
mechanical using fans or systems to bring in and circulate outside air, and expel stale/damp inside air
a combination of both.

Effective ventilation can maintain air quality, increase thermal comfort and reduce humidity and the potential of mould. It should be paired with effective airtightness or draught proofing.

While doors and windows designed for ventilation are useful for letting in cool air when open, poor sealing can lead to unwanted draughts – cold air in winter or hot air in summer.

Find out more about ventilation and airtightness on Your Home.

Rebates and assistance

Explore our rebates and assistance page to find out if you are eligible for rebates and other assistance to install insulation and improve the energy efficiency of your home.

Heating and cooling

Seasonal tips to save energy

Insulation Your Home

Ventilation and airtightness Your Home

Advice for Insulation and draught proofing NSW Government

Draught proofing a home Victorian Government

Insulation and draught proofing ACT Government