Choosing uPVC joinery in Wellington
uPVC windows mean a new frame, so choosing uPVC double glazing gets you new joinery instead of new glass in the old one. If the frames you've got aren't worth keeping, it's one way of getting double glazed windows into an older Wellington home. Before you compare quotes, ask the maker what wind zone the windows are rated for.
Ask for a quote
Is uPVC strong enough for a windy site?
We can't answer that for uPVC in general, and we haven't found a source that does. What counts is whether the window you're quoted is rated, under the window standard NZS 4211, for the wind zone at your site.
WGANZ, the Window & Glass Association NZ, says each new window has to be labelled for the zone it's fitted in. There's more about those labels, and how each site's zone is set, for anyone replacing the windows in a Wellington house.
Questions for the maker
- Which wind zone is this window rated for?
- Does that zone match the one for my site?
- Does the glass meet NZS 4223.4 for the wind load at my site?
- What will the label on each window say?
Put them to whoever measures up for your quote, and ask for the answers in writing.
R-values for uPVC, and the R0.46 reference
An R-value measures how well the whole window, frame and glass together, keeps heat in. A higher figure means less heat escapes. In MBIE's table, uPVC rates above both kinds of aluminium frame and a little below timber, with either glass.
Aluminium
Standard double glazing
R0.24
High-performance glass
R0.35
Thermally broken aluminium
Standard double glazing
R0.30
High-performance glass
R0.46
uPVC
Standard double glazing
R0.37
High-performance glass
R0.63
Timber
Standard double glazing
R0.41
High-performance glass
R0.71
The figures come from MBIE's H1/AS1, sixth edition. The high-performance column assumes glass rated Ug 1.3. WGANZ puts a single-glazed timber window at roughly R0.19.
The region's councils fall into two of H1's climate zones, 3 and 4. In H1/AS1's sixth edition, current since 27 November 2025, the reference building assumes R0.46 windows for a new home in either zone. That's a figure for designing new houses. In one that's already built, new windows don't have to reach it, but they must keep in at least as much heat as the ones coming out.
With high-performance glass, uPVC and timber go past R0.46, and thermally broken aluminium lands on it. Standard aluminium falls short with either glass. So does every frame with standard double glazing. If you're also pricing new aluminium windows and joinery, ask whether each quote is for thermally broken frames.
Reference windows for new homes
R0.46
Climate zones 3 and 4
Zone 3 takes in Wellington City, Lower Hutt, Porirua and Kāpiti Coast.
Zone 4 takes in Upper Hutt, Masterton, Carterton and South Wairarapa.
Building consent applications made before 27 November 2026 can still use the fifth edition.
H1/AS1 figures as at September 2026.
Have uPVC priced on your own openings, and ask what R-value those windows reach with the glass in the quote.
Ask for a quoteuPVC comes as a new frame
Choosing uPVC changes the frame, so the job is joinery as well as glass. Ask how much of the old joinery comes out, and whether the quote covers making good around the new frames, inside and out.
Building consent isn't usually needed for new windows in a house up to two storeys high, but the District Plan can still call for resource consent.
Heritage and Character Precinct houses
Wellington City's rules for heritage buildings, heritage areas and Character Precincts treat new frames as an alteration, so a frame change there can need resource consent.
Timber sashes, casements and the heritage rulesWhat else people ask about uPVC
What is uPVC?
The u stands for unplasticised. uPVC is a rigid PVC used to make window and door frames.
Is uPVC the same thing as double glazing?
No. Double glazing means two panes of glass sealed into one unit, and uPVC is what the frame around it is made of. Aluminium and timber frames take the same kind of unit.
How much are uPVC windows in Wellington?
We don't give a uPVC price, because the published figures we found are too far apart to rely on. There is a national band for a three-bedroom house, $32,000–60,000 for new uPVC or thermally broken aluminium windows, though GST isn't stated in it.
A job that size needs a written contract, which the Building Act requires from $30,000 incl GST. For the retrofit and standard aluminium bands, see how double glazing is priced in Wellington.
Which uPVC brand should I choose?
We don't rank brands or makers. Two uPVC windows can differ in the glass they come with and the wind zone they're rated for, so compare quotes on those rather than on the name.
Can I swap timber windows for uPVC in a Character Precinct?
Expect to need resource consent, since swapping timber frames for uPVC counts as an alteration under the precinct rules. Before anything's ordered, check how those rules treat timber sashes and casements in Wellington.
What are the downsides of choosing uPVC?
On national figures it's dearer than a retrofit, because the frames are new too. For a three-bedroom house, the bottom of the band for uPVC or thermally broken aluminium sits above the top of the retrofit band.
See what uPVC would come to on your house
Fill in the form and say it's uPVC you're after. We'll pass the enquiry to a local installer. Ask for the quote to spell out the frames, the glass and the making good.