How much does it cost to double glaze a whole house in NZ?
A typical NZ whole-house job is about $16,000, most $10,000–25,000 (CheckMyBuilder). A worked 3-bedroom example for retrofit and replacement.
By the NZ Double Glazing team
Key takeaways
- A typical whole-house double glazing job in New Zealand is about $16,000, with most between $10,000 and $25,000 (CheckMyBuilder, checked 15 Sep 2026).
- Retrofitting existing aluminium windows runs $550–850 a window, timber $800–1,200; full replacement $1,500–2,500+ per opening (Wellington Glass).
- On a worked example of 12 windows, that is roughly $6,600–10,200 for an aluminium retrofit, $9,600–14,400 for timber, and $18,000–30,000+ to replace the lot.
- An old house usually means timber joinery, which costs more per window to retrofit but is also the strongest case for keeping the frames.
- Your own window count and sizes are what move the number. Count them before you compare quotes.
Double glazing a whole three-bedroom house in New Zealand typically costs about $16,000, and most jobs land between $10,000 and $25,000 (CheckMyBuilder, checked 15 September 2026). Retrofitting your existing frames sits at the bottom of that range; replacing every window with new joinery sits at the top or above it.
What does a whole house cost, window by window?
The quickest honest way to get to a whole-house number is to count the windows and apply the published per-window rates. A three-bedroom house has a window or two in each bedroom, a few in the living and dining area, and smaller ones in the kitchen, bathroom and laundry. Twelve is a reasonable count to work with as an example; yours may be ten or fifteen.
| Route | Per window | 12 windows |
|---|---|---|
| Retrofit, aluminium frames | $550–850 | $6,600–10,200 |
| Retrofit, timber frames | $800–1,200 | $9,600–14,400 |
| Full replacement, new joinery | $1,500–2,500+ | $18,000–30,000+ |
The same house priced by glass area lands in the same place. If those twelve windows add up to around 18 m² of glass, retrofit at $450–800 per m² comes to $8,100–14,400 and replacement at $800–1,600 per m² to $14,400–28,800 (CheckMyBuilder). Large ranchsliders and picture windows push the area figure up quickly, which is why a house with a lot of glass facing the view costs more than its bedroom count suggests.
Why does an old house cost more to double glaze?
Older New Zealand houses, villas and bungalows especially, usually have timber joinery: double-hung sashes, casements and fanlights, often with glazing bars. A timber sash takes more bench time to rebate for a thicker sealed unit than an aluminium frame does, which is why the published retrofit rate for timber is higher. Sash windows can also need new cords or weights to carry the heavier glass.
The other cost in an old house is what the measure finds. Soft sills, paint-stuck sashes and rot at the bottom rail all have to be fixed before a new unit goes in, and they are priced on top. It is still usually cheaper than replacement, and it keeps the joinery that gives the house its character. Our timber window retrofit page goes into what can and cannot be retrofitted.
What else goes on top of the window price?
- Repairs to frames, sills or sashes found at the measure.
- Refitting curtains, blinds and pelmets after the work.
- Repainting or staining the sashes.
- Scaffolding on a house of two storeys or more: $1,000–5,000 (CheckMyBuilder).
Does it cost more in Auckland or Wellington?
A little. CheckMyBuilder puts a typical whole-house job at $18,000 in Auckland, $17,000 in Wellington and $16,000 in Christchurch. The per-window and per-m² rates are national; the regional typical moves because house sizes, window counts and the mix of retrofit and replacement work differ.
How can I bring the whole-house cost down?
- Retrofit rather than replace wherever the frames are sound. On a whole house that is often a five-figure difference.
- Do the rooms you live and sleep in first, then the rest. Glazing splits cleanly by room, so staging it costs little extra.
- Leave out windows that matter least: a small laundry or toilet window adds cost for little comfort.
- Get the ceiling and underfloor insulated first if they aren't. That is co-funded for many households; glazing isn't (see is there a double glazing grant).
How do I get a number for my house rather than an example?
Walk the house with a tape measure and write down every window: room, width, height and whether it opens. Put that list into our double glazing calculator for a range on each window and a total. A measure then checks the frames and turns the range into one fixed written quote.
Questions
How much does it cost to double glaze a 3 bedroom house in NZ?
Typically about $16,000, with most whole-house jobs between $10,000 and $25,000 (CheckMyBuilder). On a 12-window example, an aluminium retrofit is roughly $6,600–10,200, timber $9,600–14,400, and full replacement $18,000–30,000+.
How much does it cost to replace all the windows in a house with double glazing?
Full replacement runs $1,500–2,500+ per opening (Wellington Glass) or $800–1,600 per m² of glass (CheckMyBuilder). For a house with 12 windows, expect $18,000–30,000 or more before scaffolding and finishing.
Is it cheaper to retrofit double glazing on an old house?
Usually, yes. Retrofit costs roughly half of replacement per m² of glass. Old timber joinery is dearer to retrofit than aluminium, at $800–1,200 a window, and any rot found at the measure is extra, but it still tends to come in well under replacement.
How long does it take to double glaze a whole house?
Retrofit is mostly workshop work, so time on site is short and spread across a few visits, with windows boarded or swapped room by room. Replacement is more of a building job. Your quote should give a programme for your house.
Can I do just part of the house?
Yes, and it is a sensible way to budget. Start with the bedrooms and living area, where you spend the most time, and price the rest so you know the full number.
Do I need a building consent to double glaze the whole house?
Usually not. Window work in an existing house of up to two storeys is commonly exempt under Schedule 1 Exemption 8 of the Building Act, with conditions. See does double glazing need building consent.
Published 9 October 2026, last updated 9 October 2026 by the NZ Double Glazing team.