RetroGLAZE Double Glazing Cost Calculator
Plan your home upgrade with confidence
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Your Likely Project Range
About Our Calculator and the cost of Double Glazing
As a basic guide for New Zealand projects, retrofit double glazing typically models at $450–$800 per m², while full replacement commonly sits around $800–$1,600 per m². The cost band is so wide because of all the project variables that come into play like joinery type and condition, safety glass, glass types, glass area etc. However, our calculator is built on data from years of completed NZ projects and pricing logs, and it matches your specifications to projects with similar room amounts, glass area, joinery type, safety-glass share, and installation conditions in our database. That lets us generate a data-backed NZ cost range for your home, rather than a generic average that ignores the details that move the number.
Window wisdom.
Our calculator is built on years of real project data gathered from trusted partners across New Zealand. Together we’ve completed thousands of retrofits in homes and apartments across the country. When you enter your project specifications, the tool compares your inputs with closely matched jobs in our database. That means your estimate isn’t a guess. It’s grounded in what similar projects actually cost to supply and install.
Final pricing is always confirmed after a quick site measure to check frame condition, safety glass zones, and any scaffolding requirements.
Deciding whether to retrofit or replace your windows and doors can feel confusing, draining, or even overwhelming.
Retrofit double glazing uses your existing aluminium frames, replacing the old single glazing with new double glazing, whereas replacement double glazing involves removing both the existing glass and frames of your aluminium or timber windows and doors, replacing them with thermally enhanced joinery. Read more here…
Timber frames usually need more prep and finishing, which can add labour. Heritage profiles and thin rebates can also slow things down because they call for careful handling and custom trims. uminium, by contrast, tends to install faster because profiles are consistent, tolerances are tighter, and retrofit beads clip or screw in with fewer finishing steps. There is typically no painting, less cleanup, and fewer surprises on site. Read more here….
Lots of factors come into play here, for example large panes, toughened or laminated safety glass, acoustic or Low-E coatings, and tricky access raise the cost of each window. Every window has different needs. Read more here…
Take control of your window upgrade journey.
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