Field guide · 6 min · 26 April 2026
What does double glazing actually cost in NZ in 2026?
A real cost breakdown for the three common NZ scenarios — single-room retrofit, whole-house retrofit, whole-house full-frame replacement — with the line items installers don't always volunteer.
Double glazing in 2026 NZ is more affordable than it was five years ago, mostly because more local IGU manufacturing has come online (Auckland and Christchurch both have meaningful local capacity now) and the import-dependent price spike of 2022 has unwound. Here's what current quotes actually look like, by scenario.
Scenario 1: single-room retrofit (e.g. main bedroom)
Spec sheet
- 2× window retrofit IGUs (1.2m × 1.0m)
- $1,300 – $1,900
- Site visit + measure
- Usually free, sometimes $150
- Sash removal + reinstall
- Included
- Beading + finishing
- Included; touch-up paint extra
- Total typical
- $1,400 – $2,000
A single-room retrofit is the gateway most NZ homeowners use to test whether they like the result before committing to whole-house. A clear win on warmth and condensation in that one room within a week of install. The installer's economics on a single-room job are tight — expect a longer scheduling lead time than a whole-house job because the per-day revenue is lower.
Scenario 2: whole-house retrofit (12-window timber villa)
Spec sheet
- 12× window retrofit IGUs
- $8,000 – $11,500
- Sash workshop work
- Included
- Joinery weather-sealing (good installers include)
- $0 – $1,200
- Sill repair / rotten timber replacement (variable)
- $0 – $2,500
- Total typical
- $9,000 – $13,500
Whole-house retrofit is where most installers do their best work — the per-window cost drops, the crew is on site for a sustained block, and they can do the whole sash-out/IGU-in cycle as a controlled workshop process. The variable above the IGU cost is sill and frame repair: it's not until the installer pulls a sash that they can tell you whether the underlying timber is sound.
Scenario 3: whole-house full-frame aluminium (90s tract house)
Spec sheet
- 14× full-frame thermally-broken aluminium
- $22,000 – $32,000
- Removal + disposal of old joinery
- Included
- Building paper + flashing rework around openings
- $1,500 – $4,000
- Internal reveal + architrave repaint
- $2,000 – $5,000
- Total typical
- $26,000 – $40,000
Full-frame is meaningfully more disruptive — there will be open holes in the wall briefly during install, internal linings near the reveals will need touch-up, and the cladding interface needs to be properly flashed. Budget realistically for the secondary trades: the glazing line item is only ~70% of the total spend.
What about payback?
Honest answer: heating-savings payback for double glazing in NZ is typically 15–30 years on whole-house retrofit, and longer than the joinery's life on full-frame replacement. Don't buy double glazing primarily as an investment in lower power bills. Buy it for warmth, condensation, noise, and resale value. Those returns are real and immediate; the kWh savings are a bonus, not the case.
The grants and finance bit
There's currently no national EECA insulation grant covering glazing (the previous Warmer Kiwi Homes scheme covered ceiling and underfloor only). Some regional councils run small subsidies — Wellington and Christchurch have rotated schemes through 2024–2026. Heat-Smart Wellington is the most active. Check your local council before assuming you're paying full retail.