Cool your home in summer

Last updated: 6 September 2022

Fans and air conditioners play their part when cooling a house but passive techniques that focus on windows, ventilation, insulation and landscaping can reduce energy consumption and be instrumental in keeping a house cool during the heat of the summer months.

Passive cooling

The ability to cool down your home in summer and reduce your energy consumption and costs is affected by five key factors.

1. Insulation

Insulation is the most effective way to improve the comfort and energy efficiency of your home. A fully insulated home means you'll spend less on heating in winter and cooling in summer.

2. Draught proofing

Draught proofing, or sealing up gaps and cracks, will minimise the amount of heat entering your home and reduce your cooling bills.

3. Window design, orientation and coverings

Windows can let a lot of heat into your home during summer, especially if you have large west, east and north-facing windows that aren't adequately shaded. Fortunately there are simple steps you can take to reduce heat gain through your windows.

4. Ventilation

Ventilation is also an important way to regulate your home's air temperature and keep it free of condensation build-up, which can result in mould, rot or damp. Once the temperature starts to drop in the evening, or after a cool change, it's important to open your doors and windows to flush warm air from your house and allow cooler outside air to enter. The benefits are likely to be greatest if you open doors and windows facing the breeze and also doors and windows on the opposite side of the house.

5. Landscaping

Careful selection and positioning of plants can provide summer shading and act as a buffer against hot winds. Tall, deciduous canopy trees provide shade to north windows while still allowing the lower winter sun through. Smaller, deciduous shrubs are useful for shading east and west windows and walls. Deciduous creepers over a north-facing pergola will provide shade for windows and walls.

Active cooling

If you need to actively cool your home with supplementary cooling, choose the most appropriate system for your needs.


Ceiling, wall-mounted and portable electric fans can be a cheap and effective way to stay comfortable on warm, humid summer nights.

Evaporative cooling

Evaporative cooling systems draw air through a moist pad, cooling and humidifying the air before it is blown through your house. They are available in ducted, wall-mounted and portable units, and work best in hot, dry conditions. Evaporative coolers are less effective on humid days, and are not well suited to humid climates.

Air conditioners

Air conditioners extract heat from the air inside your house and transfer it outside, cooling the air to a temperature determined by a thermostat. They are available in portable, room and ducted systems.