Thermal mass and wall insulation

Insulation is the simplest and most common way to help regulate the temperature.

The most practical and comfortable homes are those that have been built in response to the surrounding climate. This means taking into account the range of temperatures your local area typically experiences - considering in particular the highs and lows that occur throughout the year as well during during the day and night.

Where possible, you should take advantage of passive heating and cooling devices (e.g. the sun, shade and wind), rather than relying on artificial methods of temperature regulation alone (heaters and air conditioners). Ensuring your walls are well insulated and have an appropriate thermal mass will assist in regulating the temperature of your house - or maintaining its 'thermal comfort'.

Walls that are designed in response to the climate, with an appropriate thermal mass and the right kind of insulation will:

1. Keep your living space comfortable
2. Lower your heating and cooling costs
3. Preserve natural resources

Thermal mass

Thermal mass describes the ability of a material to absorb and store thermal energy. Some materials have what is described as a high thermal mass, others have a thermal mass that is lower. In climates where there are cool winters and a reasonable variance between temperatures during the day and night, a wall built with materials that have a high thermal mass can be used to keep the temperature inside your home fairly static. Stone, concrete, earth and brick are all wall-building materials which have a high thermal mass.


However, thermal mass must be harnessed properly, or you risk constructing walls that draw heat indoors during warm days and then absorb it from your heating devices in cooler weather. Thermal mass often needs to be used in conjunction with insulation and passive heating and cooling for it to work well.


Insulation works to help protect your home from uncomfortable weather. Much of the thermal energy in a home is gained or lost through the roof and ceiling, however the walls do play an important role in effective insulation. The right kind of wall insulation will not only help to regulate temperature and keep the inside of your house dry, but may even have the added bonus of soundproofing. However, unless your home incorporates the principles of passive design, insulation is often useless or may even exacerbate the uncomfortable temperatures you are aiming to neutralise.

Similarly, the wrong type of insulation can work against you by blocking heat when you want to retain it and vice-versa. To choose the right sort of insulation for your home, first decide whether you need primarily to keep it warm, keep it cool, or a combination of the two. Local councils will be able to provide you with information about what sort of insulation will suit your needs best.


When considering how best to regulate the temperature inside your home, don’t forget to protect yourself from draughts! These can be responsible for significant heat loss in cool climates. Australian homes have been found to be significantly more draughty than homes in Europe and North America.