Double glazing questions

Retrofit into existing frames is $450–800 per m² of glass; full replacement is $800–1,600 (CheckMyBuilder, checked 15 Sep 2026). A typical whole-house job is around $16,000, most between $10,000 and $25,000. The full cost page.

Wellington Glass publishes $550–850 for an aluminium retrofit window, $800–1,200 for timber, and $1,500–2,500+ per opening for full replacement.

Because they are usually pricing different things: retrofit versus replacement roughly doubles the figure, timber costs more than aluminium, and Auckland runs above the national typical.

No. EECA's Warmer Kiwi Homes programme co-funds ceiling and underfloor insulation and heat pumps, not glazing.

Yes. Every figure on this site is in New Zealand dollars including GST.

Usually, if the joinery is sound and deep enough to take a thicker sealed unit. Rot, corrosion or a distorted frame generally means replacement instead. The measure is what settles it.

They should. Sealed units are heavier, so hinges, stays, sash cords and rollers get checked at the measure and anything that needs doing is priced then.

It cuts it a lot, because the inside pane is much warmer, but it does not remove moisture from the room. What it changes and what it doesn't.

It adds 5–10% to the price (Wellington Glass), and EECA puts the performance improvement from a low-E coating at up to 30% and argon fill at 5–20%. The calculator shows it as its own line.

EECA says up to 40% of a home's heating energy is lost through windows, dropping to 25% or less with double glazing. We do not convert that into dollars for your house, because no source we would cite gives a figure that transfers.

Usually not for window work in an existing dwelling of up to two storeys, under Schedule 1 Exemption 8, provided the window being replaced hasn't failed its 15-year durability requirement. Exempt work must still meet the Building Code. The conditions.

H1/AS1 6th edition (27 November 2025) removed the Schedule Method, which is where the old R0.46 / R0.50 window figures came from. The 5th edition can be used until 26 November 2026. What changed.

Residential building work of $30,000 or more including GST needs a written contract, and the contractor must give you a disclosure statement and the MBIE checklist before signing. We give all three on every job, whatever it costs.

A retrofit glazier we contract in your area makes the sealed units and fits them. We price, measure, manage and hold the contract, and we name the glazier before they visit.

A free measure is paid for by the people who buy, and it arrives with a salesperson. We charge $149, credit it in full to a job signed within 60 days, and send nobody to sell you anything.

$149 for the measure and quote, then a 25% deposit when you accept the quote so your units can be made, then the balance at completion.

In full if we can't offer a measure within 10 working days, if you cancel 48 or more hours before, or if the quote is late. After the visit it isn't refundable, but it is credited to a job signed within 60 days. Terms of trade.

Not until a glazier is under contract in your area, we're GST registered and insured, and our contract template and terms are published. Until then every button joins a waitlist and takes no money.

Auckland, Wellington and Christchurch first. Where we work. The calculator works anywhere in New Zealand.