It has been estimated that this Government initiative, (of which S.A. was the first state to adopt in September 2010), could increase the building cost to the average size home in the vicinity of approx. $4,000. When Building, it is extremely important to think about orientation(s) as this is now a critically important consideration; and obviously the orientation of your land re: frontage is (also) now an extremely important factor.
Planning your home
- Avoid building houses larger than they need to be, and plan efficiently.
- A big issue is often the larger the house, the more resources used to construct it, and the more energy needed to heat, cool and light it.
- See how you can achieve the same functionality using less m2 (eg. Efficient layouts, good storage design, etc.)
- Maximise winter sun to living areas, and solar collectors (northerly orientation ideal).
- North-facing facades receive the sun for the longest part of the day, and are easiest to shade in summer.
- For living areas, N-NE orientation is generally ideal. For solar collectors, NE-N-NW orientation is fine.
- Create separate zones that can be independently heated or cooled.
Basic building envelope design
- Use a moderate total amount of glazing.
- Glazing is usually the “point of least resistance” in a house, for heat loss and gain.
- Locate openings to encourage natural ventilation.
- Opposite or adjacent walls of living areas and bedrooms.
- High windows for “stack” ventilation.
- Shade glazing from summer (not winter) sun.
North facing glazing
- North facing glazing is easiest to shade “passively”.
- Properly designed eaves will admit winter sun, and exclude summer sun.
- Face most glazing north where practicable.
West facing glazing
- Face least glazing to the west where practicable.
- East and west facing glazing needs protection from low angle summer sun.
- Use adjustable external shading capable of shading the whole window as the sun is at a lower angle.
- Each m2 of un-shaded west-facing glazing in summer can radiate as much heat as a 700w bar heater.
Choosing construction systems
Use low embodied energy materials, unless there is a clear thermal performance or durability benefit in doing otherwise.
- The ideal solution will vary with climate.
- There is often a trade off between embodied energy and thermal performance.
- This is because in some situations, materials with high embodied energy, are very beneficial to thermal performance.
- For example, heavyweight construction materials usually have high embodied energy, but also high thermal mass.
- High thermal mass can be very beneficial to thermal performance in many (but not all) situations.
Our next blog will discuss “Thermal Performance”.