Other factors contributing to heat gain

Got a two storey home?

The first floor of a two storey house is generally more sun exposed than the ground floor and can be difficult to shade. The first floor may receive less shade from trees and other buildings, and is likely to pick up rising hot air from the ground floor. As a result first floors are usually much hotter in summer than ground floors.   External shading is the preferred way to keep the first floor cool naturally. This can be achieved with similar devices to those used in single storey houses. Wide eaves, horizontal shading structures and vertical awnings over sun exposed windows or walls are generally very effective, however it may be difficult to raise or lower standard awnings on a first floor because they are likely to be out of reach from the ground. An alternative is to install external awnings that can be wound up/down from inside the house or even going to the expense of electrically operated awnings or shutters. Installing thermal ‘skins’ especially on sun exposed west and east facing walls is also very effective.

Doors and windows left open during the day

For the same reason that we keep windows and doors closed on cold winter days to stop heat escaping, it’s very important to keep doors and windows closed on summer days – to keep your house as cool as possible for longer.

On the mornings of hot days, close up the house and shade all windows to block out the summer heat.  Be mindful to allow some fresh air to enter the house if you are home, preferably from the shaded (and therefore cooler) side of your house. It is particularly important to keep the house closed up on a hot day if the ceiling is insulated, because if hot air can enter from outside, the insulation will trap that hot air inside.

Concrete and Paving  Horizontal awnings used to shade paved or concreted areas.

Large areas of unshaded concrete, rocks or paving around your house absorb sun and heat up during the day and then radiate that heat back on to walls and windows, heating up the house well after the sun has gone down and often into the night. If concrete or paving abuts your house without a gap, the heat can transfer easily through the slab of the floor, heating the inside of the house. Therefore consider shading not just windows and walls, but pavers and concrete paths beside the house as well. This can be done with vegetation or if this is not possible, by shade sails or even painting the concrete white. Using gravel to cover this area (i.e. instead of concrete / paving) will also reduce the heat transfer through the slab of the house floor.