The short answer
Check four things before you compare prices: that the quote is fully installed rather than supply-only, that each window has a WERS rating, that any Victorian discount appears as its own line, and, for a big Victorian job, what contract it comes with. Work worth more than $10,000 generally needs a major domestic building contract, and contracts over $20,000 come under Home Warranty.
Is it installed, or just the windows?
This is where most price gaps come from. The Melbourne range of $2,300 to $3,500 per window is for the whole job. The same company warns that prices well under its range are usually supply-only, or are imported product without AS 2047 testing. A quote that is missing reveals, sealing and disposal is not cheaper, it is smaller, and the rest turns up later.
Are the two quotes even for the same windows?
Check the schedule, not the total. Sizes, opening styles and glass specification all move the number, and so does counting seven windows instead of nine. Ask for the WERS heating and cooling stars, which run 0 to 10 stars, and for Uw and SHGCw, so you are comparing whole windows rather than panes of glass. The ratings come from AFRC-accredited raters, which is why they are worth asking for by name.
How should the Victorian discount appear?
On its own line, with the area behind it. The published rate is up to $210 per 10 m², the work needs approved products only, and your final price is set by your accredited provider. If the discount is folded into a bundled price, you cannot tell whether you received it.
What contract and Home Warranty cover does the job need?
Where a window job crosses the Victorian thresholds
Show the numbers
| Item | Range |
|---|---|
| One window, Melbourne | $2,300 to $3,500 |
| Ten windows, Melbourne | $23,000 to $35,000 |
| Whole 3 bedroom home, Perth | $18,000 to $20,000 |
| Marker: Major contract over $10,000 | $10,000 |
| Marker: Home Warranty over $20,000 | $20,000 |
One window sits well below both lines. A whole house clears them both. In Victoria, Consumer Affairs Victoria says domestic building work worth more than $10,000 needs a major domestic building contract in writing, though it lists single-trade jobs, including glazing-only jobs, among those that don't. If your quote includes new reveals, plastering or other making good, ask the installer in writing whether it is being treated as glazing alone.
Since 1 July 2026, building contracts over $20,000 for homes of three storeys or less come under the Home Warranty scheme run by the Building and Plumbing Commission, which covers lost deposits, incomplete work and defective or non-compliant work. Contract law is also changing: the new rules take effect by 1 December 2026, so check the date on any guide you read, including this one. Other states set their own thresholds, so check your own regulator rather than assuming these travel.
Per window or per square metre?
Either is fine as long as every quote uses the same basis. Remember that small windows come out higher per m², because measuring, making and fitting cost much the same whatever the size. A per-square-metre rate flatters a house of large openings and punishes a house of little ones.
| Line on the quote | What to look for |
|---|---|
| Scope | Fully installed, with reveals, sealing, removal and disposal named |
| Window schedule | Every opening listed with size and style, and the count matching your house |
| Product | Frame material, glass specification, and AS 2047 testing |
| Performance | WERS heating and cooling stars, plus Uw and SHGCw |
| Discount | The VEU line, the approved product, and the area it was worked out from |
| Paperwork | The contract type, and Home Warranty details where the contract value requires them |
| Timing | Lead time from measure to install, and who makes good inside |
One last check
Before signing, read the quote back against your own list of windows, room by room. It's a dull ten minutes, and the cheapest ten minutes in the whole project.