Ask five joinery companies what it costs to replace your windows and doors, and you'll get five different numbers — and none of themwill be wrong. At Number One Windows and Doors, we quote Christchurch homesevery week, and the honest answer is: it depends on what's actually going intothe opening, not just what's printed on a price list.

Here's what actually moves the number.

Style Changes the Labour, Not Just the Look

Sliding, bifold, French, awning, casement — these aren't interchangeableoptions at different price points for the same job. A bifold door needsmultiple panels, running gear, and precise track alignment across the fullwidth of the opening, which is a different job entirely to fitting a singleawning window. If you're choosing a style purely on appearance, factor in thatthe more moving parts a design has, the more it costs to get right.

Why We Build in Aluminium

Timber has genuine appeal and uPVC insulates well, but for Canterbury'sexposure — nor'wester winds, coastal salt air, sharp frosts — aluminium is whatwe'd put in most homes here. It doesn't need repainting every few years liketimber, it won't warp or swell with moisture, and it holds tight tolerancesover decades, which matters more than people expect once a frame's been througha few Canterbury winters.

That's the whole reason our range — the Omega 300, 500, and 800 Series — isaluminium through and through. The three sit at different thermal performanceand sightline levels, so the material decision and the "which series"decision are actually two separate conversations, not one.

Size and Shape Move the Numbers More Than Style Does

A standard-sized double-hung window and a full-height bay window aren't in thesame cost bracket, even in the same material and style. More glass, moreextrusion, more structural support at the opening — all of it adds up beforelabour even enters the equation. Custom shapes (angled heads, non-standard openings)add fabrication time on top of that. If your opening isn't a standard size, getit measured before you compare any quotes against each other.

Double Glazing Pays for Itself Here

Double glazing with argon fill and a Low-E coating costs more upfront thansingle glazing — no way around that. But in a Christchurch winter, thedifference in how a room actually feels is immediate, and it's not a marginalupgrade the way it might be in a milder climate. If budget's tight, this is theone place we'd tell you not to cut the spec.

Installation Is Where Cheap Quotes Get Expensive

A frame that's slightly out of square, poorly sealed, or fitted without properflashing will draught, leak, or fail early — and it'll usually void themanufacturer's warranty on the joinery itself, regardless of how good theproduct was. The install is not a line item to shop down; it's the differencebetween a window that performs for twenty years and one that needs revisitingin three.

Timing and Local Supply

Lead times on aluminium extrusion and glass can shift with supply and demand,and that affects both price and how far out you should book if you're planningaround a renovation timeline. Get a quote with a real installation dateattached, not just a headline number — that's what tells you whether the priceis actually current.

None of this is a reason to put off the decision — old, draughty, or damagedjoinery costs you every winter you leave it. It's a reason to get a propermeasure and a real quote rather than guessing from a price list. Get in touchand we'll walk you through what your specific job actually needs.

FAQs

How much does window and door replacement actually cost?

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It depends on style, size, and glazing spec more than anything else — there'sno single number that applies across every home. A measure and quote is theonly way to get an accurate figure for your place.

Is double glazing worth it in Canterbury?

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Yes. Given how cold Christchurch winters get, the comfort difference isnoticeable immediately, and it's one of the few upgrades that keeps paying youback every heating season.

Why does installation quality matter so much?

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A poorly fitted frame — out of square, badly sealed, missing flashing —undermines even the best joinery. It's also the most common reason manufacturerwarranties get voided, so it's worth checking who's actually doing the install,not just what brand is being fitted.

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