How the estimate works

The calculator multiplies your glazing area by the per-m² range a Melbourne window company publishes, and separately multiplies your window count by its per-window range. In Victoria, if the windows are single glazed, it takes off the VEU discount of up to $210 per 10 m²↗, pro rata by area.

Where do the prices come from?

Nobody official publishes window prices, so the ranges come from window companies, and we name them. Double glazed replacement is $1,200 to $1,800 per m²↗ or $2,300 to $3,500 per window↗. Secondary glazing is $300 to $650 per m²↗ or $1,800 to $3,400 per window↗. These businesses sell windows, so read them as a seller's view of the market.

Why don't the two estimates match?

They come from different price lists. Per-m² rates suit larger windows: the source quotes them for windows of 1.5 m² and above, and says smaller windows come out higher per m²↗ because measuring, making and fitting cost about the same whatever the size. For a house of small windows, trust the per-window row more.

How is the Victorian discount applied?

The program states the discount as up to $210 per 10 m²↗ for homes with single-glazed windows↗. The calculator scales it to your area, which is an assumption: the price you pay after the discount is set by your accredited provider↗, and it needs approved products only↗.

What does the estimate leave out?

Glass upgrades such as laminated or low-E glass, and bushfire-rated products.
Structural repairs to frames, sills or walls found during removal.
Anything a very low advertised price hides: such prices are usually supply-only↗, according to the same Melbourne company.

In Victoria, building work over more than $10,000↗ needs a major domestic building contract. See how to read a window quote.

Sources

Victorian Energy Upgrades (energy.vic.gov.au): Victorian Energy Upgrades discount to double glaze windows. Checked 2026-09-12.
Victorian Energy Upgrades (energy.vic.gov.au): Victorian households and most businesses with single-glazed windows can receive the window glazing discount. Checked 2026-09-12.
Victorian Energy Upgrades (energy.vic.gov.au): You must install a product on the VEU register of approved products to be eligible for the discount. Checked 2026-09-12.
Victorian Energy Upgrades (energy.vic.gov.au): Your final installation cost, including the discount, is determined by your accredited provider. Checked 2026-09-12.
Consumer Affairs Victoria: Domestic building work costing more than $10,000 requires a major domestic building contract, which only a registered building practitioner may enter. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): A Melbourne window company reports double glazed windows cost this much per window, fully installed, in 2026. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): A Melbourne window company reports double glazing costs this much per square metre, fully installed, for windows of 1.5 m² and above. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): Smaller windows work out higher per square metre because measure, fabrication and installation costs apply regardless of size. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): Advertised prices well below the installed range are usually supply-only, exclude timber reveals, disposal and sealing, or are imported product without AS 2047 testing. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): A Melbourne window company reports installed secondary glazing costs this much per window, fixed windows at the lower end and tilt and turn at the upper. Checked 2026-09-12.
Windows Republic (Melbourne uPVC window maker): A Melbourne window company reports professionally installed secondary glazing systems generally run this much per square metre. Checked 2026-09-12.