Research shows that about 40% of day to day energy use comes from heating and cooling the space we live in. In these days of climate change awareness, passive solar building design is not just a do-good feel-good gimmick – it means measurable day-to-day cost-saving which will also be reflected in higher sales prices when the property is eventually sold.

Many home owners realise that by the time they sell (homes sell on average every seven to ten years), energy-savvy design will be even more highly sought after as energy prices come to match environmental impact concerns.

Read on to find out what’s involved in incorporating passive solar design into your building or renovation project.

Passive solar design – in its simplest form - means keeping the heat of the sun out of the home in summer and attracting the sun inside in winter. Most passive solar features cost little or nothing if incorporated at the design stage so if you’re building or renovating a home, it’s worth talking to whoever is designing your home.

The following points will help you ask the right questions and get the energy efficient outcomes you are looking for.

1. Orientation
Orientation comes down to intelligent use of the sun. It doesn’t cost anything but the decision about which way the home will face must be made before the foundations are laid. Choose the ideal direction to maximise sun use during winter and restrict sun use at the hottest times of year (in the Southern hemisphere this means a north orientation for day use areas and south for night use).

2. Zoning
Clever zoning means placing the daytime areas of the home towards the northern side and the night time areas to the south or east (it’s easy to stay warm in bed and days are spent in the living areas.)

3. Glazing
Well-placed and well-sized windows reduce the need for artificial lighting during the day. At the same time, the fact that glass is a poor insulator needs to be taken into account; double glazing or some other form of insulation such as heavy curtains may be necessary at night time or on sunless winter days in most climates. Unprotected single-glazed windows lose ten times more heat in winter than the same area of insulated wall. Windows can also be designed to let sun shine on interior walls and floors that can be built of materials that have the thermal mass to store it.

4. Insulation
No matter what the climate, insulation for walls, roofs and floors is crucial in energy-efficient design, keeping heat inside the house during winter and outside in summer. In some cases the building material itself may be the insulator (e.g mud bricks, double brick).