What Is Low-E Glass? Australian Costs, U-Values & Is It Worth It
Low-E glass (low-emissivity or low-emittance glass) carries a microscopically thin metal coating that reflects heat back where it came from — halving window heat loss versus standard glass for only 10–20% more cost. That makes it the single most cost-effective upgrade for meeting 7-star NatHERS, in single or double glazing.
Target specs by climate zone
| Climate | U-value | SHGC (north) | Glass type |
|---|---|---|---|
| Cool (Melbourne, Hobart, Canberra) | ≤ 2.0 | 0.5 – 0.6 | DGU + Low-E (soft coat) |
| Mixed (Sydney, Adelaide, Perth) | ≤ 3.0 | 0.4 – 0.5 | DGU + Low-E |
| Hot (Brisbane, Darwin) | ≤ 3.5 | ≤ 0.35 | Solar-control Low-E |
Indicative costs (installed)
- • Single glaze (baseline): $400 – $700/m²
- • Standard DGU: $550 – $900/m²
- • DGU + Low-E (aluminium): $700 – $1,200/m²
- • DGU + Low-E (uPVC / timber): $1,200 – $2,200/m²
- • Triple-glazed Low-E: $1,800 – $3,000/m²
Payback & comfort
- • Halves window heat loss vs standard glass
- • Eliminates cold-glass downdraughts
- • Reduces condensation on frames
- • 6–12 year payback in cool climates
- • Often makes 7-star achievable without exotic walls
Get a glazing schedule modelled for your home
Your NatHERS assessor models every window in your design so you know exactly which need Low-E and which don't — saving thousands on over-specification.
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