Window Orientation and Glazing: Designing for Free Stars
Where you place windows matters as much as the glass you choose. Here is how to use orientation to gain rating points at no extra cost.
Windows are the most powerful and most misunderstood element of a home energy rating. They let in light, warmth and breezes, but also heat you do not want. Place them well and you earn free stars. Place them poorly and no glass upgrade fully recovers the loss.
Each direction behaves differently
| Direction | Behaviour | Strategy |
|---|---|---|
| North | Low winter sun, easy to shade in summer | Favour living-area glazing here |
| South | Little direct sun, steady light | Good for even daylight, modest sizes |
| East | Morning sun, hard to shade | Moderate sizes, better glass |
| West | Harsh afternoon heat | Minimise and shade, upgrade glass |
The golden rule
Concentrate glazing on the north, keep it modest and well shaded on the west, and avoid oversized windows on orientations that only bring heat. This costs nothing during design and saves a fortune in glazing upgrades later.
Glass is the second decision, not the first
Owners often jump straight to double glazing. The better sequence is to right-size and orient the windows, shade them properly, then upgrade the glass only where the orientation demands it. That keeps premium glazing budget focused on the few openings that truly need it.
Do not forget the breeze
Windows positioned for cross-ventilation reduce reliance on air conditioning, which helps both comfort and the energy side of compliance. Catching the prevailing breeze is another free lever many designs leave on the table.
Frequently asked questions
Can great glass fix bad placement? It helps, but it cannot fully undo a west wall of unshaded glass. Placement comes first.
How early should windows be set? At concept stage. Moving a window on paper is free. Moving it on site is not.
Want your window layout reviewed for free stars? Explore our thermal performance service.
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10 Tips for a 7-Star New Build
Our practical PDF guide to building a comfortable, compliant NSW home - the design decisions that matter most, and how to reach 7 stars without overspending.
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BASIX & NatHERS specialists helping NSW homeowners and builders achieve energy-efficient, compliant homes.