Aluminium windows, joinery and ranch sliders in Wellington
Aluminium windows and doors bought as new joinery replace the frame and the glass together, rather than fitting new glass to the old frames. Owners start asking about it when old aluminium lets water in during storms, or when they want wooden windows swapped for aluminium. If you haven't settled on new frames yet, compare the routes to double glazed windows for older homes in Wellington first.
Ask for a quote
New aluminium windows when the whole frame is replaced
The old window comes out, frame and all, and a new aluminium window made for that opening goes in. The joinery is made after the openings are measured, so ask how long that takes and get the timeframe in writing.
Sound, dry aluminium frames may only need new glass. Have yours checked before you order new joinery, and compare the price of double glazing the aluminium frames you already have.
Under NZS 4211 a new window is rated for wind and water in its wind zone, so ask which zone the joinery is being made for, as you would when replacing windows in timber or uPVC.
Aluminium doors, French doors and bifolds
Doors can go on the same joinery job as the windows, whether it's a pair of French doors, a bifold or a ranch slider. Like the windows, they come in standard or thermally broken aluminium.
When a new door won't seal
A thermally broken door that never sealed, even after callbacks, is one of the complaints owners have posted about. Before you sign, ask who comes back to adjust a door that won't seal, and read how the workmanship warranty is worded.
When the doors are in, open and close each one and check the seals and hardware before the installer leaves.
Prices for new frames, doors and sliders
A Wellington glazing firm's published list gives new aluminium windows a single price per opening, with no split between standard and thermally broken frames. We only have national figures for the thermal break, and on those it adds 25–40% to each opening.
We haven't come across a reliable published price for aluminium doors, French doors, bifolds or ranch sliders on their own, so ask for each door as its own line on the written quote.
How double glazing prices add upPublished by a Wellington glazing firm, February 2026
Full aluminium replacement
$1,500–2,500+
per opening, incl GST
The prices hadn't moved when we looked again on 17 September 2026
Listing every window and door you want replaced, including ranch sliders and bifolds, lets a local installer price the joinery as one job.
Ask for a quoteThermal breaks in new aluminium frames
In MBIE's table of whole-window R-values, a thermally broken aluminium window rates higher than a standard one with either kind of glass. Some quotes use standard frames as the base, which makes them hard to compare. Ask which frame each price is for.
The top figure, R0.46, is what MBIE's current reference building assumes for a new home's windows in the Wellington region, not a figure your replacement windows have to meet, and uPVC joinery rates above it with the same glass.
Whole-window R-values
Standard aluminium, standard double glazingR0.24
Thermally broken, standard double glazingR0.30
Standard aluminium, high-performance glassR0.35
Thermally broken, high-performance glassR0.46
From MBIE's H1 acceptable solution, 6th edition. High-performance glass here means a unit rated Ug 1.3. A higher R-value means less heat lost.
Safety glass in doors and low-level panes
NZS 4223.3 calls for safety glass wherever someone could hit the glass or fall. In a house that means doors and their side panels, low-level panes, bathrooms and stairways, where the glass is within two metres of the floor or ground.
Old glass in those places that isn't safety glass may need upgrading when a window or door is replaced, even when the work needs no building consent. Installers say a low sill is one thing that brings safety glass into a quote.
What people ask about aluminium windows and doors
How much is a new aluminium window in Wellington?
The published Wellington price for new aluminium windows is per opening, frame and glass together, not per glass unit, so count openings when you compare quotes.
Can I swap wooden windows for aluminium under heritage rules?
Check first. MBIE gives replacing wooden windows with aluminium in the same position as an example of work exempt from building consent, but a heritage or Character Precinct rule can still require resource consent, so look up the heritage rules on timber sashes and casements before you order.
Is there a cheaper option than new aluminium joinery?
On published prices, new glass in sound frames usually costs less than new joinery, so look at double glazing aluminium frames on older houses before you decide.
What are the drawbacks of aluminium frames?
On MBIE's figures the drawback is heat loss, because even a thermally broken aluminium window rates below uPVC windows and timber ones when the glass is the same.
Ask for the windows and doors on one written quote
At the measure, ask for every opening to be priced twice, once in standard frames and once thermally broken. Your enquiry goes from the form to a local installer.