The warm-frame option for new joinery
uPVC double glazing in Auckland
uPVC double glazing puts the sealed unit in a plastic frame that doesn't conduct heat the way aluminium does, so the frame stays nearer room temperature and the sill stays dry. It can't go into your existing frames, so it means new joinery. To find out whether it beats thermally broken aluminium on your house, get both quoted on the same openings.
Get a quotePublished uPVC prices in New Zealand disagree by two to four times, so we haven't made a number up. If you're still weighing up frames, compare them on double glazing in Auckland.
How uPVC compares with aluminium and timber
| Frame | Standard double glazing | Low-E and argon | Frame and condensation | Upkeep |
|---|---|---|---|---|
| Standard aluminium | R0.24 | R0.35 | Metal runs straight through, so the inside face runs cold and wet | Wash down |
| Thermally broken aluminium | R0.30 | R0.46 | A plastic strip stops the cold partway through the frame | Wash down |
| uPVC | R0.37 | R0.63 | Plastic doesn't conduct heat, so the frame stays nearer room temperature | Wash down |
| Timber | R0.41 | R0.71 | Timber doesn't conduct heat either | Paint |
Whole-window R-values from the Building Code's H1/AS1 reference table. Higher is warmer. Single glazing in a timber frame is about R0.19, so any of the four is a big step up from that.
With the same glass, uPVC is a much warmer window than plain aluminium, and it's the frame that stops sweating. Against thermally broken aluminium the gap is narrower.
For new work in Auckland, the code's reference building assumes R0.46 windows. With high-performance glass, uPVC beats that and thermally broken aluminium matches it. Plain aluminium doesn't get there with either glass. A replacement in an existing house only has to perform at least as well as what it replaces, so R0.46 is a yardstick rather than a requirement.
What uPVC is, and how it relates to double glazing
uPVC stands for unplasticised polyvinyl chloride, a rigid plastic without the softeners that make PVC pipe flexible, extruded into hollow frames. Plastic conducts far less heat than aluminium, and that's where uPVC's higher R-values come from.
uPVC joinery is often tilt-and-turn, where the top of the sash leans in for airing or the whole sash swings open into the room. You can also get awning and sliding windows in uPVC.
uPVC or double glazing?
They aren't alternatives. Double glazing is the glass, a sealed unit of two panes with a gap between them. uPVC is one of the frames it can sit in, alongside aluminium, thermally broken aluminium and timber. So uPVC double glazing means new uPVC frames with sealed units in them. Double glazing on its own could be any of the four, including a retrofit unit in the frames you already have. If your frames are sound, that's the cheaper place to start.
Where uPVC gives something up
None of these rules it out. They're the things to ask about before you sign.
Frame size and sightlines
uPVC sections are thicker than aluminium, so the same opening carries less glass and the frames look heavier from the street. Ask to see a sample section, and ask what the sightline will be on your windows.
Colour
White is the usual finish. Ask whether a colour or a woodgrain changes the price, and whether it's in stock or on order.
Sun and the warranty
People ask on the forums whether uPVC holds up under New Zealand UV. Ask about the profile's UV stabilisation and what the frame warranty says about fading and distortion, and get the answer in writing.
Who fits it
Ask where the profile is made, who will be fitting it, whether they fit uPVC regularly, and whether you can see a job they did a few winters ago.
uPVC means new joinery, not a retrofit
A retrofit keeps your frames and swaps the glass. uPVC can't be retrofitted into an aluminium or timber frame, because uPVC is the frame. So choosing it means window replacement. The old joinery comes out, the reveal gets made good inside and out, and you pay replacement prices. Building consent is usually not needed on a house of up to two storeys, under Schedule 1 of the Building Act, as long as the work meets the Building Code.
In a Special Character Area, watch for resource consent, because the frame swap is what triggers it. In a Mt Eden villa case reported in 2025, aluminium frames had replaced the original timber sashes and the council issued an abatement notice. Its heritage manager said on record that units fitted into the existing wooden frames wouldn't have needed consent. uPVC frames in place of timber sashes on a street-facing wall is the same change.
Have uPVC and thermally broken aluminium quoted on the same windows
Ask for the same openings and the same glass priced in both frames, so the only thing that differs is the frame.
Getting a uPVC price that means something
We haven't put a per-window price on uPVC, because the New Zealand sources can't even agree whether it costs more or less than thermally broken aluminium.
A real price comes from a quote. Ask for it per window, not per pane, with the glass spec written down (low-E or clear, argon or air), the profile and where it's made, the frame warranty and the installation warranty as separate items, and what making good is included. Then get the same openings quoted in thermally broken aluminium so you can compare. There's more on why double glazing prices vary so much.
- uPVC, per windowNot published
- 3-bedroom, thermally broken or uPVC$32,000–55,000
- 3-bedroom, standard aluminium, for comparison$20,000–45,000
- Standard aluminium, per window~$1,200–2,700
Published Auckland installer pricing, 2026. Most sources don't say whether GST is included.
uPVC questions
What does uPVC stand for?
Unplasticised polyvinyl chloride, a rigid plastic without the softeners that make PVC pipe and cable flexible. uPVC double glazing is a sealed unit in a frame made from it.
What are the disadvantages of uPVC windows?
The frames are thicker than aluminium, so you get a bit less glass and a heavier look from the street, and white is the usual finish. It can't go into the frames you have, so it's always a window replacement. Ask about UV stabilisation and what the warranty says about fading, and get it in writing.
How much do uPVC windows cost in NZ?
New Zealand sources disagree on a per-window price by two to four times, so we haven't published one. A three-bedroom house in uPVC or thermally broken aluminium comes to $32,000 to $55,000 in published Auckland pricing for 2026. There's more on why the ranges are so wide under what double glazing costs in Auckland.
What's the difference between uPVC and double glazing?
Double glazing is the glass, a sealed unit of two panes with a gap between them. uPVC is one of the frames it can sit in, so uPVC double glazing means sealed units in new uPVC frames. Double glazing on its own could also be a retrofit into the frames you already have.
Want a real uPVC number instead of a range?
Send your name and number. The installer measures on site and writes down the profile, the glass and the price per window.