Penrith summers hit 40 degrees and the M4 traffic doesn’t quiet down until after midnight. Double glazed windows fix both problems in one job. We supply and install double glazed windows across Penrith, Emu Plains and Glenmore Park for retrofits, new builds and rear extensions where owners want the room to actually feel like a room, not a heat trap. Getting double glazed right is about the whole unit: two panes, the right cavity, a solid spacer bar, and framing that doesn’t leak air around the perimeter.
What an IGU actually is
An insulated glass unit (IGU) is two panes of glass sealed to a spacer bar with an argon-filled cavity between. The cavity is typically 12 mm or 16 mm. The spacer is warm-edge (usually TGI or Super Spacer), not old-style aluminium. One or both panes carry a Low-E coating that reflects heat back where it belongs. That coating is what does most of the thermal work, not the double glazed panes on their own.
Thermal and acoustic gains
A well-spec’d double glazed unit gets you a U-value around 1.6 to 2.0 W/m2K, compared to 5.7 for old single-glazed. In real terms, a west-facing living room in Jamisontown that used to hit 32 degrees at 4 pm sits closer to 26 with the same aircon load. For acoustic upgrades near the motorway or the airport flight path, we spec asymmetric panes (6 mm laminated outer, 4 mm float inner) with a wider cavity. That knocks off 8 to 12 dB of traffic noise, which is the difference between hearing every truck and hearing none.
- Standard clear IGU: 4 mm float, 12 mm argon, 4 mm Low-E
- Acoustic IGU: 6.38 mm laminated, 12 mm argon, 4 mm float
- High-performance IGU: 4 mm Low-E, 16 mm argon, 4 mm Low-E
- Custom sizes for bifold, sliding, awning and fixed lite windows
Retrofit or new build
Retrofits are the bigger part of our work. Most 1970s to 1990s brick veneer homes in Cranebrook and Kingswood have aluminium frames with single-glazed clear glass. We measure the existing sash or frame, order the new IGUs to fit the existing rebate, and swap them out over half a day per window. For new builds and extensions we work off the builder’s window schedule and supply full aluminium or timber frames with the IGUs already fitted.
Retrofit steps on site
Take out the existing bead, lift the old glass, clean the rebate, re-block, set the IGU on rubber blocks, re-bead and seal. About 60 to 90 minutes per window for a straight swap. Larger sliding doors and awning windows take longer because the sash comes off the frame.
Cost drivers
A standard IGU retrofit into an existing aluminium frame lands around $450 to $850 per window depending on size and glass type. New aluminium double glazed windows supplied and installed run $900 to $2,400 per opening. Timber-framed double glazed is a different price bracket again, usually 40 to 60 percent above aluminium. Coatings, laminated interlayers and larger sizes push the number up. We provide fixed-price quotes after a site measure, not per-square-metre estimates over the phone.
What to watch for
Double glazing only works if the frame doesn’t leak. A cheap aluminium frame with no thermal break loses most of the benefit through the metal. Ask for thermally-broken framing where the whole-of-window U-value matters. Also watch the seals: a 20-year-old sash with worn brush pile will let air past the glass no matter how good the IGU is. For frameless bathroom upgrades on the same renovation, see our frameless shower screens page. For patio and stacker sliders being upgraded to double-glazed, see the patio door service.
If you’re planning a renovation or want a quote on retrofitting an existing home, give us a call. 02 4722 2787. We cover Penrith, Glenmore Park, Emu Plains, St Marys and the rest of Western Sydney.
Frequently asked questions
Will double glazing pay for itself?
On energy costs alone, payback is usually 8 to 15 years depending on climate zone and how heavily the aircon runs. Comfort and noise reduction start on day one.
Can I keep my existing timber frames?
Sometimes. If the frame is sound and the rebate is deep enough (usually 22 mm minimum) we can retrofit IGUs. If the rebate is too shallow, the whole sash needs re-machining or replacing.
Does argon really matter?
Yes. Argon is denser than air and gives about a 10 percent U-value improvement. Every reputable IGU is argon-filled at manufacture.
What’s the warranty on IGUs?
10 years on seal failure from the manufacturer, provided installation follows the fabrication guide. We supply the paperwork on handover.