Double Glazing Retrofit Cost Calculator
Estimate the cost of retrofitting double glazing to existing windows. Enter the number of windows, you can replace whole windows or (cheaper) retrofit a second pane into existing frames, and the method drives the price.
Your double glazing retrofit details
Your estimate sits within the typical range.
Double glazing cuts heat loss, heat gain and noise. Retrofitting a pane to existing frames is far cheaper than full window replacement, though replacement with uPVC frames performs best. Prioritise the rooms you use most.
💰 Ways to save
- Retrofit a second pane to existing frames to get most of the benefit for far less than full replacement.
- Do the rooms you use most, or the noisiest/sunniest windows, first if budget is tight.
- Compare aluminium versus uPVC frames, uPVC insulates better but costs more.
or from $43/week over 5 years , indicative finance
How we estimate this
Retrofitting double glazing in Australia typically costs around $800 to $1,200 per window for new double-glazed units in 2026, less for retrofitting a pane to existing frames, and more for uPVC frames. A whole house of 10 to 15 windows often runs $8,000 to $25,000.
Pricing reviewed: November 2026.
Pricing reviewed November 2026. Indicative Australian costs, not a quote.
Understanding double glazing retrofit costs in Australia
Retrofitting double glazing in Australia typically costs around $800 to $1,200 per window for new double-glazed units in 2026, less for retrofitting a pane to existing frames, and more for uPVC frames. A whole house of 10 to 15 windows often runs $8,000 to $25,000.
You can replace whole windows or retrofit a second pane into existing frames, which is much cheaper. uPVC frames insulate best but cost more than aluminium. Prioritising the most-used or noisiest rooms controls the budget.
Frequently asked questions
How much does double glazing cost in Australia?
Roughly $800 to $1,200 per window for new double-glazed units in 2026, less for retrofitting a pane to existing frames, more for uPVC. A 10 to 15 window house is often $8,000 to $25,000.
Is retrofit double glazing cheaper than replacing windows?
Yes, retrofitting a second pane into your existing frames (or a secondary internal pane) is much cheaper than replacing whole windows, and keeps the existing frames, useful for heritage homes.
Are you a glazing / window business?
Everyone on this page is working out what double glazing retrofit costs because they are ready to hire. Put your business right beneath the calculator, in your state, so you are who they find. From $50/mo.