The double glazing industry has a pricing transparency problem. Quotes range from $400/m² to $1,200/m² for what is, at its core, the same product: two panes of glass sealed with an aluminium spacer bar and a perimeter seal.
This guide breaks down what you are actually buying, what the components cost, and what represents fair value for a Melbourne retrofit job.
What You Are Paying For
A retrofit double glazing installation has three distinct cost components:
1. The glass unit (IGU) The insulating glass unit is the hermetically sealed assembly — glass panes, spacer bar, desiccant, gas fill (air or argon), and primary/secondary seal. This is where most of the performance variation sits.
2. Installation labour Removing existing glass, preparing the rebate, installing glazing tape and seals, setting the IGU, and trimming. On a standard residential window, this takes 20–40 minutes per pane for an experienced glazier.
3. Margin This is the variable. A well-run glazing business needs 30–40% gross margin to cover overhead, warranty provisions, and profit. Above 45%, you are likely being overcharged.
Pricing by Glass Type
| Glass specification | Supply-and-install (per m²) |
|---|---|
| Standard clear float, 24mm IGU | $495 – $580 |
| Tinted glass (grey, bronze, blue) | $520 – $610 |
| Hard-coat Low-E | $560 – $680 |
| Soft-coat Low-E + argon fill | $620 – $750 |
| Acoustic laminated (single pane) | $630 – $780 |
| Acoustic laminated + Low-E | $750 – $920 |
| High-performance acoustic (6.38mm PVB) | $820 – $1,050 |
Prices above are for retrofit into existing frames, Melbourne metropolitan area. Full window replacement adds $200–$400/m² for frame supply and installation.
Why Quotes Vary So Much
Ask three glaziers for a quote. You will likely get three wildly different figures. Here is why:
Glass sourcing
Large glaziers manufacturing in-house have lower glass costs than small operators buying from distributors. The savings are not always passed on.
Assessment of difficulty
Tight access, upper-floor windows, non-standard sizes, and heritage rebate profiles all add time. Some glaziers pad for this upfront; others quote low and charge variations.
Margin strategy
Trade glaziers working off a volume model operate at tighter margins than retail-focused businesses with showrooms and salespeople. You often pay for the showroom without knowing it.
The fix: ask for itemisation
Request a quote broken down by glass specification, panel count, and installation. Any glazier who refuses is hiding margin. Compare the line items, not the totals.
What Good Value Looks Like
For a typical 15m² whole-home retrofit with standard Low-E glass, fair pricing in Melbourne sits between $9,000 and $11,500 installed. If a quote is:
- Under $7,500 — query the glass specification and warranty terms. Corners are likely being cut on IGU quality or seal specification.
- $11,500–$14,000 — normal range for premium hard-coat Low-E or acoustic specification, or jobs with access complexity.
- Over $14,000 — ask for itemisation. You may be paying full replacement prices for a retrofit job.
Instant Estimate: See the Number Before You Call
Use the Instant Estimate tool to enter your window count and sizes and immediately see an itemised price. No email required, no sales call triggered.
It is the fastest way to know whether a glazier's quote is reasonable — and the exact figure that appears on our invoices.
See also: Full pricing breakdown for all glass types
Main service
Double Glazing Cost & Pricing →