Double Glazing Cost Calculator
Double glazing is priced three very different ways in Australia depending on whether you retrofit, replace or add a secondary pane. Choose the approach and the glass, and the calculator returns a realistic installed bracket.
Retrofit only works where the existing frame can accept the extra unit depth.
The frame matters as much as the glass. Fitting a high performance insulated glass unit into a plain aluminium frame lets the frame short-circuit much of the benefit, which is why thermally broken or uPVC frames appear in nearly every serious double glazing quote.
- Glass units (supply)$6,850
- Frames and hardware$3,000
- Installation labour$2,750
- Sealing and make-good$1,100
💰 Ways to save
- Do the coldest and hottest elevations first. South-facing rooms in Melbourne, Canberra and Hobart lose the most winter heat, and west-facing glass gains the most summer heat, so glazing those elevations properly delivers most of the comfort benefit for roughly half the whole-house cost. Living areas and bedrooms you occupy at the temperature extremes matter more than a hallway window.
- Ask whether your existing frames can take a retrofit unit before you price full replacement. Many aluminium and timber frames in reasonable condition can accept a slim insulated glass unit, which costs roughly a third less than replacing the whole window and avoids all the reveal, render and architrave make-good. A glazier can tell you in one site visit.
- If noise is the real problem, specify for noise rather than buying generic double glazing. Acoustic performance comes from a wide air gap and two panes of different thickness, not from the label. Secondary glazing with a 100mm gap frequently outperforms a sealed 12mm unit on traffic and aircraft noise at a much lower price, which is the opposite of what most quotes assume.
- Check for state efficiency incentives and lender green loan discounts before you commit. Several Australian states have run household energy upgrade programs that include glazing, and a number of banks offer discounted green home loan rates for verified efficiency improvements, either of which can materially change the payback on a $15,000 project.
or from $65/week over 5 years , indicative finance
Run a blinds & shutters business? Put a calculator like this on your own website, branded as yours.See how →How we estimate this
## What double glazing costs in Australia
Pricing reviewed: June 2026.
Pricing reviewed June 2026. Indicative Australian costs, not a quote.
Are you a blinds & shutters business?
Put this calculator on your own website, branded to you, visitors get an instant estimate, you get a qualified enquiry with their details.
Understanding double glazing costs in Australia
What double glazing costs in Australia
Double glazing in Australia typically costs $800 to $1,800 per window installed in 2026, so a whole-house project on ten to fourteen openings usually lands between $10,000 and $28,000. The three routes to get there price very differently. Retrofitting an insulated glass unit into an existing frame runs roughly $550 to $1,100 per window where the frame can take the extra depth. Full replacement with new double glazed windows costs $900 to $2,000 per opening depending on frame material and size. Secondary glazing, which adds a second independent pane over the existing window, is the cheapest at around $400 to $850 per window. Sliding and stacker doors sit well above all of those, commonly $3,000 to $7,000 per unit.
Retrofit, replacement or secondary glazing
Choosing between the three is the most consequential decision in the project. Retrofit suits homes with sound aluminium or timber frames that have enough rebate depth for a slim insulated glass unit, and it avoids all the reveal, render and architrave make-good that full replacement triggers. Full replacement is the right answer when frames are already failing, when you want thermally broken or uPVC frames, or when the existing frames simply cannot accept a thicker unit. Secondary glazing keeps the original window entirely and mounts a second pane on an internal track or magnetic frame, which makes it the standard solution in heritage properties where the original joinery must stay, and the best value option where noise rather than heat is the complaint.
Glass specification and what each upgrade buys
A standard clear insulated glass unit is two panes with a spacer and a sealed cavity, and it roughly halves heat transfer compared with single glazing. Low-E coating adds a microscopically thin metallic layer that reflects radiant heat, improving the U-value materially for around 15 per cent more, and it is the single most cost-effective upgrade in the list. Argon gas fill in the cavity adds a further increment for around 10 per cent more again. Acoustic laminated glass uses an interlayer to damp sound and is the right specification where traffic, rail or aircraft noise drives the project. Toughened or laminated safety glazing is mandatory rather than optional in doors, wet areas and low-level glass under AS 1288, so expect it as a line item rather than a choice in those locations.
Frames, thermal bridging and why the frame matters
Fitting excellent glass into a poor frame is the most common way to waste money on this upgrade. Standard aluminium conducts heat efficiently, so an unbroken aluminium frame around a high performance unit creates a thermal bridge that undermines the whole assembly and often shows up as condensation on the frame even after the glass stops fogging. Thermally broken aluminium inserts a polyamide barrier between inner and outer frame sections and typically adds 40 to 50 per cent to the frame cost. uPVC insulates very well natively and has become common in Victoria and Tasmania, though it needs UV-stable formulation for Australian exposure. On a full replacement project, the frame decision usually moves the total more than the glass decision does.
Performance, condensation and realistic expectations
Double glazing delivers three benefits in different measures. Comfort is the most reliable: rooms feel noticeably more even, cold radiant surfaces disappear in winter and afternoon heat is blunted in summer. Noise reduction is real but specification-dependent, and buyers are frequently disappointed because a narrow sealed cavity with two identical panes does relatively little for low frequency traffic noise. Energy savings are genuine but modest against the capital cost in mild Australian climates, with typical payback periods running well over a decade unless you are in a cold climate zone with high heating use. Condensation usually improves on the glass because the inner pane sits closer to room temperature, but if the underlying problem is household humidity, the moisture simply reappears on the next coldest surface, so ventilation and extraction need attention at the same time.
Standards, incentives and getting a comparable quote
Glazing in Australia must comply with AS 1288 for safety and human impact, AS 2047 for weatherproofing and structural performance in new window installations, and the relevant National Construction Code provisions for new work and significant alterations. Products should carry an AFRC or equivalent rating showing U-value and Solar Heat Gain Coefficient, which are the two numbers that let you compare quotes objectively rather than by brand claims. Several states have run household energy upgrade programs that include glazing, and some lenders offer discounted green home loan rates for verified efficiency work, both worth checking before you sign. When you compare quotes, insist that each states the U-value, the SHGC, the cavity width, the pane thicknesses and the frame type, because two $15,000 quotes with those specifications hidden are not comparable products.
Frequently asked questions
How much does double glazing cost in Australia?
Typically $800 to $1,800 per window installed in 2026, so a whole-house project on ten to fourteen openings usually costs $10,000 to $28,000. Retrofitting a unit into an existing frame runs $550 to $1,100 per window, full replacement $900 to $2,000, and secondary glazing $400 to $850.
Is retrofit double glazing as good as replacement?
Thermally it is close on the glass itself, but it keeps the original frame, so if that frame is plain aluminium it will still conduct heat and can still show condensation. Retrofit is excellent value where frames are sound and deep enough to take the unit, because it avoids all the reveal, render and architrave make-good that full replacement triggers.
Does double glazing actually reduce noise?
Yes, but only if specified for it. Noise reduction comes from a wide air gap and two panes of different thickness, not from double glazing in general. A sealed 12mm cavity with two identical panes does relatively little for low frequency traffic noise, while secondary glazing with a 100mm gap often outperforms it at a much lower price.
What is the payback period on double glazing?
In most Australian climates it runs well over a decade on energy savings alone, and longer in mild coastal zones. The reliable returns are comfort, reduced condensation and noise, plus resale appeal. Cold climate zones with high heating loads, such as Canberra, Hobart and alpine areas, produce the shortest paybacks.
Is Low-E glass worth the extra cost?
Usually yes. A Low-E coating reflects radiant heat and improves the U-value materially for around 15 per cent more than standard clear insulated glass, making it the most cost-effective single upgrade in the specification list. Argon fill adds a smaller further improvement for roughly 10 per cent more again.
Can I put double glazing in a heritage home?
Often only as secondary glazing, which mounts a second pane internally and leaves the original joinery untouched. Heritage overlays commonly prohibit replacing original timber sashes, and secondary glazing is the solution most councils accept because it is reversible and invisible from the street. Confirm with your council before ordering.
Run a blinds & shutters business? Add this double glazing cost calculator to your own website →