Home wall insulation

Last updated: 15 September 2022

Insulate your existing walls and your ceiling during your renovation, and you will reduce your home's heating and cooling costs by up to 40% and significantly increase your overall comfort in the long-term.

Safety first

Ensure that you read our insulation health and safety tips before considering installation or repair of insulation. Learn to minimise risk to yourself and your property.

Select the right insulation

There are two main types of insulation – bulk insulation and reflective foil insulation.

If you are removing the internal lining of your walls, there is a range of insulation batts that may be suitable for your wall insulation, including polyester, glass wool, rock wool and natural wool.

Select the right R value

The R value is a measure of a material's resistance to heat flow (known as thermal resistance). The higher the R value, the greater the resistance to heat transfer, the greater the insulating effect and the greater the energy (and therefore money) savings. Different products with the same R value will provide similar insulation performance, regardless of thickness or the type of material.

For the Victorian climate the recommended R value for wall insulation is R2.5, with a minimum requirement of R1.5.

Installation tips

In Victoria, most walls can be divided into three distinct categories:

Brick veneer walls

Brick veneer homes have a higher R value than weatherboard and will lose less heat in winter. Brick veneer homes built before 1990 are likely to have no insulation in the walls. Adding insulation to the timber frame of your walls will keep heat inside your home in winter and stop heat from outside entering your home in summer. A renovation is an ideal time to insulate your existing brick veneer walls, to save money on your energy bills and improve the comfort of your home.

Double-brick walls

Brick has thermal mass properties: it stores heat from the sun and releases it slowly into your home overnight. This is great in winter, but not so great during summer heat waves. Double-brick walls have a high R value and can be harder to insulate. Learn to insulate your double-brick walls to keep the heat in during winter and out during summer, saving money on your energy bills and improving the comfort of your home.

Weatherboard or lightweight cladding walls

A weatherboard or other lightweight wall has a low R value, meaning heat and cold will readily transfer from inside to outside. This will make it very difficult for you to heat the inside of your house on a cold day. A renovation is an ideal time to insulate your weatherboard or lightweight cladding walls, to save money on your energy bills and improve the comfort of your home.