Every second window quote we do lately includes the question: is it worth going double glazed? For a lot of Penrith homes the answer is yes, but not always for the reason people think. Here is the honest breakdown of when double glazed windows Penrith side actually pay back, and when they do not.
What double glazing actually is
A double-glazed unit (also called an IGU, insulated glass unit) is two panes of glass separated by a spacer bar, with dry air or argon gas trapped between them. The gap does the insulating work. A typical residential IGU is 4-12-4, meaning 4 mm glass, 12 mm gap, 4 mm glass. Total thickness around 20 mm, weight roughly double a single pane.
Where double glazed windows Penrith side pay back fast
Three scenarios stand out. West-facing living rooms that turn into an oven from 2pm in January. Master bedrooms with a big window facing a busy road (Great Western Highway, Mulgoa Road, the M4). And any new build or extension where you are already opening the wall and the labour is sunk.
Where it does not pay back
South-facing windows that get no direct sun anyway. Small bathroom and toilet windows. Windows in rooms you rarely use. Windows behind mature trees. If comfort was not a problem before, spending $600 to $1,200 per window to marginally reduce a bill you did not notice is not a great return.
The real numbers we quote for double glazed windows Penrith side
- Standard single-glazed aluminium window (1.2 x 1.2 m): $450 to $750 supplied and installed
- Same window in double glazed windows Penrith spec: $850 to $1,600
- Upgrade cost per window: $400 to $850
- Estimated cooling season saving per west-facing window: $30 to $80 per year
- Estimated payback on a west-facing single-to-double swap: 7 to 15 years
Numbers vary with orientation, glass area and how hard the aircon runs. The comfort improvement is immediate and real, the dollar payback is medium-term.
Acoustic performance, the underrated benefit
The reason we sell most double glazed windows Penrith side is not thermal, it is acoustic. A single 6 mm pane sits around Rw 30 for sound rating. A well-specced double glazed unit with a laminated inner leaf can push Rw 40 to 45. That is the difference between hearing every truck downshifting on the Northern Road and hearing a muffled thud. For homes in Kingswood or Penrith on the main road grid, that alone justifies the upgrade in the bedrooms.
Retrofit versus new install
Retrofitting IGUs into existing aluminium frames is possible for some sash types but not others. The original frame has to be deep enough (typically 22 mm rebate minimum) or you replace the whole frame. Timber sash windows are usually retrofitted with a secondary internal pane instead, which is cheaper and preserves the original joinery. See our window repair page for both options.
Weighing up single versus double for your place? Ring 02 4722 2787 for a room-by-room assessment. We will tell you honestly where the upgrade pays back and where a single-pane laminated does the job for less.
Frequently asked questions
Can I get double glazing in only the noisy rooms and single in the others?
Yes, this is the most sensible way to spend the budget. Prioritise west-facing living areas and street-facing bedrooms. Leave laundry, ensuite and unused rooms as single-glazed unless you are replacing the frame anyway.
Do double-glazed units ever need replacement?
The seal around the perimeter has a design life of 15 to 25 years. When it fails, moisture enters the gap and the unit fogs internally. The IGU has to be swapped out (usually keeping the same frame). Manufacturer warranties typically run 5 to 10 years on the seal.
Is Low-E glass worth the extra on top of double glazing?
For west-facing rooms in Western Sydney summer, yes. Low-E coating reflects infrared radiation and drops solar heat gain by 30 to 60 percent. Adds around $80 to $150 per window on top of the IGU cost. Best value upgrade after the double glazing itself.
