Christchurch's older timber and aluminium joinery stock means most homes in the city are still running single glazing, and windows remain the weakest thermal link in a typical Canterbury house. We've independently verified the double glazing installers below against real reviews, industry membership and genuine local track record, not just who shows up first in search.
This page highlights the Top 5 double glazing installers in Christchurch, based on independent research into reputation, accreditation, service quality and overall reliability.
The top 5 double glazing installers in Christchurch are 1. ComfortGlaze, 2. Thermoglaz, 3. Canterbury Glass, 4. RetroFit Double Glazing (Metro Direct Christchurch), 5. Birchfield's Glass & Glazing. Below we explain why each made the list, compare them at a glance, and share how to choose.
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ComfortGlaze High Performance Retrofit Ltd is based at 10 Garlands Road, Woolston, is a WGANZ member, and carries a 5-star Google rating across roughly 97 reviews, one of the strongest independently verified review counts of any Christchurch glazing specialist.
Thermoglaz NZ Ltd operates from 20 Kennaway Road, Woolston, is a confirmed WGANZ member, and has traded across Canterbury for 15+ years, offering both retrofit and full frame replacement rather than only one method.
Canterbury Glass is a WGANZ member based in West Melton with a 4.8 Google rating, 22 staff and its own factory manufacturing insulating glass units, with retrofit double glazing experience for timber and aluminium joinery dating back to the mid-1980s.
RetroFit Double Glazing is a subsidiary of Metro Performance Glass, New Zealand's largest glass manufacturer, operating from a dedicated Christchurch branch at 45 Orbell Street, Sydenham with a 10-year manufacturer warranty on installed units and consistently positive local testimonials.
Birchfield's Glass & Glazing (2023) Ltd is a WGANZ member based at 954 Ferry Road, Woolston, with over 40 years' history in Christchurch, a 5-star Google rating from around 59 reviews, and offers both full double glazing replacement and retrofit into existing aluminium frames.
A quick comparison of our Top 5 picks. Select up to 3 businesses above to compare their strengths side by side.
| Double Glazing Installer | Best for |
|---|---|
| ComfortGlaze | Homeowners wanting a dedicated retrofit specialist with a large, verified review base |
| Thermoglaz | Homeowners deciding between retrofit and full frame replacement who want one company that does both |
| Canterbury Glass | Homeowners wanting an established local manufacturer as well as installer |
| RetroFit Double Glazing (Metro Direct Christchurch) | Homeowners wanting the backing and warranty of a large national manufacturer |
| Birchfield's Glass & Glazing | Homeowners wanting a long-established local glazier for either replacement or retrofit work |
Independent, editorial, and reviewed regularly.
TopChoice rankings are editorially curated by our New Zealand team and reviewed periodically. We don't host our own reviews. Our shortlists draw on public reputation signals from Google and other platforms, alongside our own research into each double glazing installer. We weigh up a combination of:
We don't accept payment in exchange for a place in the Top 5. Featured placements are separate and always clearly labelled. Rankings may change over time as businesses evolve.
Since May 2023, NZ Building Code Clause H1 has required a minimum window and door R-value of R0.46 in most of the country (R0.50 in the coldest zones), up from R0.37 previously. That's still well below typical wall or roof R-values, so windows remain the weakest thermal element in most Canterbury homes, even newer ones. Any glazing installed also needs to meet NZS 4223, which covers glass selection and design (Part 1) and human-impact safety requirements for glazing within 2000mm of floor level (Part 3). Checking that an installer is a WGANZ (Window & Glass Association New Zealand) member is one of the more reliable signals of a business that understands and follows these standards, rather than one just fitting glass as cheaply as possible.
There are two genuinely different approaches to consider. Full frame replacement swaps out the entire window unit, aluminium or timber joinery and all, for new double-glazed joinery, and suits homes doing a wider renovation or with frames beyond repair. Retrofit (or secondary) glazing fits new double-glazed units, or in some cases a secondary magnetic panel like Magnetite, into your existing frames, which is faster, less disruptive and cheaper, and is what most established Canterbury double glazing specialists do. Established systems in this space include RetroFit Double Glazing (a Metro Performance Glass subsidiary with roughly 40 years in the market) and Magnetite (magnetic secondary glazing, roughly 25 years). One thing worth being explicit about: unlike insulation or heat pumps, there's no EECA Warmer Kiwi Homes grant covering double glazing or window glazing, so cost comparisons between installers matter more, not less.
Retrofit double glazing in Christchurch typically runs from around $350 to $800 per pane, depending on the age and condition of the existing joinery, the glass specification used, whether scaffolding is required, and window size. Full frame replacement costs more per window since the entire joinery unit is replaced, not just the glass. Get quotes from at least two or three verified local installers to compare like for like.
No. Unlike ceiling and underfloor insulation or heat pumps, which can be funded through EECA's Warmer Kiwi Homes programme, double glazing and window glazing are explicitly excluded from that scheme. Don't budget on the assumption of a grant covering any part of a glazing project.
Full frame replacement removes the entire window, frame and all, and installs a new double-glazed aluminium or timber unit. Retrofit (or secondary) glazing keeps your existing frame and fits a new double-glazed insulated glass unit, or a secondary glazing system, into it. Retrofit is generally faster, cheaper and less disruptive, while full frame replacement suits homes where the joinery itself is failing or being renovated anyway.
For retrofit double glazing, most Christchurch homes with aluminium frames are completed within one to two days, while timber frame retrofits typically take three to five days due to the extra preparation involved. Full frame replacement takes longer per window since joinery, not just glass, is being swapped out.
Yes, for most older Canterbury homes. Retrofitting existing single-glazed timber or aluminium windows can roughly halve heat loss through the glazing, and some retrofit systems claim up to 80% reduction, alongside less condensation and noticeably reduced road and neighbourhood noise. Since windows already sit well below current Building Code R-values for walls and roofs, they're often the highest-impact single upgrade in an older Christchurch home.
Editorial disclosure: TopChoice is an independent editorial platform. Some pages may include clearly labelled featured placements for additional visibility. Featured placements do not influence rankings within our Top 5 lists.
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