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Heat transfer to and from a building occurs in only three ways: Radiation, Conduction and Convection. The physical laws and ways to control each form of heat transfer are different. Heat transfers through the roof, external walls, windows, and floor. Generally, in SE Queensland less heat transfer into the building is needed in summer, and more is needed into the building in winter. Some treatments to the building design can achieve both. Building Energy Rating cooling energy is normally more than heating energy.

To reduce Radiation heat transfer, remember both direct sunlight and indirect (sky) light:

• Use light colours on the roof and external walls
• Increase wall shading with verandahs, patios, pergolas or carports on North walls (this can also improve sun penetration in winter)
• Reduce window sizes on West facing walls
• Add window shading, awnings or louvres on East, North and West walls
• Curtains reflect some heat, heavy drapes with pelmets reflect more
• Consider window tinting or reflective film

Conduction is the major heat transfer pathway:

• Keep external surfaces cooler in summer, eg by shading or using light colours
• Insulation reduces thermal conduction through roof, ceiling and external walls
• Heat through the ceiling is controlled by ceiling insulation and roof cavity temperature
• Windows conduct much more heat than brick veneer walls
• Window coverings with pelmets add additional isolation spaces from outside temperatures
• Thermal mass (bricks and concrete) in contact with inside air, regulates temperature by absorbing heat, delaying and reducing temperature changes
• Slate or ceramic tiled floors conduct heat better than timber, cork, vinyl or carpet
• Light construction homes don't have the benefit of thermal mass and therefore require more attention to shading, windows and insulation

Thermal Convection is improved by airflow controls:

• Window size and position, cross ventilation breeze paths and ceiling fans
• Roof ventilation reduces roof cavity temperature
• Controlled infiltration or leakage of external air into the house
• Weather stripping, flue dampers, closeable vents including downlights or skylights

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