What double glazing really costs

Installed prices from Australian window companies, the Victorian discount and the NCC glazing rules. Every figure is sourced and dated.

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Double-glazed windows retain up to 30% more heat↗ and conditioned air than single-glazed windows, according to Victorian Energy Upgrades. Drag the divider, or focus it and use the arrow keys.

Installer-reported prices

Prices by glazing type

No government body publishes window prices, so these are ranges Australian window companies publish. Each company is named in the sources, and each makes or sells windows.

Double glazed replacement, Melbourne

$2,300 to $3,500 per window↗

Fully installed, or $1,200 to $1,800 per m²↗ for windows of 1.5 m² and up. Smaller windows come out higher per m²↗.

Double glazing cost guide

Secondary glazing

$1,800 to $3,400 per window↗

A second pane fitted inside the existing window. Reported at $300 to $650 per m²↗ installed.

Timber double glazed sash

$2,800 to $5,800 per window↗

The top of the market, reported by a Melbourne window company.

uPVC awning window, Perth

$800 to $1,500↗

For a 900 × 600 mm window installed. A Perth company reports $18,000 to $20,000↗ for a 3 bedroom, 2 bathroom home.

Victoria discounts double glazing by the square metre

The Victorian Energy Upgrades program takes a set amount off approved double glazing for every 10 m² you install. It comes off the quote, so you never claim it back yourself.

up to $210 per 10 m²↗

Victorian Energy Upgrades window glazing discount

Who can get it

Victorian households and most businesses with single-glazed windows↗.
Renting

In a private rental, renters are eligible↗, although landlord permission may be needed↗.
Products

approved products only↗, listed on the program's register.
Final price

The price after the discount is set by your accredited provider↗.

How the discount is worked out

7 stars↗ is the NatHERS minimum for most new houses under NCC 2022. Thermal ratings are scored out of 10 stars↗.

The NCC 7-star rule, and where windows fit

The National Construction Code sets a minimum thermal rating for new homes, and glazing is one of the biggest levers in it. The Australian Government's YourHome guide says up to 40%↗ of a home's heating energy can be lost through windows.

Warm north: In climate zones 1 and 2, houses can have 6.5 or 6.0 stars↗, depending on which provisions apply.
Victoria: In force from 1 May 2024↗, with a Whole-of-Home rating of at least 60↗.
Glazing limits: Conductance limits apply in climate zones 2 to 8↗ and solar heat gain limits in climate zones 1 to 7↗. Zone 1 is not free of glazing rules.
Renovations: In Victoria, full replacement of building elements is treated as an alteration↗, and renovating more than 50 per cent↗ of a home may bring in current energy rules.

Read the NCC glazing guide

From the blog

Each one opens with a short answer, then the detail and the sources.

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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.
Victorian Energy Upgrades (energy.vic.gov.au): Double-glazed windows retain up to 30% more heat and conditioned air than single-glazed windows. Checked 2026-09-12.
Victorian Energy Upgrades: renters, landlords and body corporate: Renters in Victoria are eligible for upgrades under the VEU program, including the window glazing discount in a private rental. Checked 2026-09-12.
Victorian Energy Upgrades: renters, landlords and body corporate: Renters should check with their landlord first, as permission may be needed depending on the type of change, the property and the length of the lease. Checked 2026-09-12.
Australian Building Codes Board (NCC energy efficiency): Minimum NatHERS rating for most houses under the NCC 2022 Volume Two deemed-to-satisfy provisions. Checked 2026-09-12.
Australian Building Codes Board (NCC energy efficiency): Houses in climate zones 1 and 2 can have either 6.5 or 6.0 stars, depending on whether specified provisions apply. Checked 2026-09-12.
NatHERS: Victoria and Queensland adopt NCC 2022: Victoria adopted NCC 2022 energy efficiency, so new houses and apartments must meet a 7-star thermal rating and a Whole-of-Home rating. Checked 2026-09-12.
Building and Plumbing Commission (Victoria): Under the NatHERS option in Victoria, new homes need a Whole-of-Home rating of not less than 60. Checked 2026-09-12.
NatHERS: home energy rating certificates: NatHERS certificates show a thermal star rating out of 10, based on the heating and cooling energy needed to keep a home comfortable. Checked 2026-09-12.
NCC 2022 Housing Provisions Part 13.3 External glazing: In climate zones 2 to 8, the conductance of glazing in each storey must not exceed the allowance from Housing Provisions Table 13.3.2a. Checked 2026-09-12.
NCC 2022 Housing Provisions Part 13.3 External glazing: In climate zones 1 to 7, the aggregate solar heat gain of glazing in each storey must not exceed an allowance based on the storey's floor area. Checked 2026-09-12.
YourHome (Australian Government): glazing: Share of a home's heating energy that can be lost through windows. Checked 2026-09-12.
Victorian Building Authority practice note EE 04: Full replacement of elements of a building does not constitute repair, renewal or maintenance and must be treated as an alteration. Checked 2026-09-12.
Building and Plumbing Commission (Victoria): If you extend or substantially renovate your home (more than 50 per cent) you may need to comply with the current energy efficiency requirements. 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): A Melbourne window company reports timber double glazed sash windows cost this much per window. 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.
Canon Double Glazing (Perth): A Perth double glazing company reports a uPVC double glazed awning window (900 × 600 mm) costs this much installed. Checked 2026-09-12.
Canon Double Glazing (Perth): A Perth double glazing company reports a complete double glazing package for a 3 bedroom, 2 bathroom home with about 20 to 25 m² of glazing runs this much. Checked 2026-09-12.