Keep your original timber windows.
Make your home warmer, quieter and more comfortable.

Double glazing retrofit replaces the single pane of glass in your existing window frame with an insulated glass unit (IGU) — two panes of glass with a sealed, gas-filled gap between them. Unlike full window replacement, retrofitting keeps your original timber frames intact, which makes it ideal for older and heritage homes where the frames themselves have character worth preserving.

It depends on the window type, pane size and frame condition. As a guide: a single fixed, casement or awning pane typically runs $360–$625 installed (ex GST), while a full double-hung sash window — both sashes, two panes, cords and rebalancing included — runs $1,200–$1,490. Smaller jobs (one or two panes) carry a slightly higher cost per pane, since a standard installation visit (travel, setup and clean-up) applies regardless of job size. The best way to get an accurate number is our instant estimator or a free on-site quote.

No — that's the main advantage of retrofitting over replacement. The original timber frame, sash and external appearance stay exactly as they are. Only the glass itself is upgraded, so the window keeps its heritage character while gaining modern thermal and acoustic performance.

In most cases, no — retrofitting doesn't alter the external appearance of the window or the building. That said, if your property is in a heritage overlay it's worth checking with your local council first. We can advise based on similar jobs completed across Banyule, Heidelberg, Eaglemont and Ivanhoe.

A fixed pane typically takes around 2 hours to retrofit, casement and awning sashes closer to 3 hours due to the extra hardware involved, and a full double-hung sash window around 8 hours given both sashes need to come out, be reglazed and rebalanced. Most residential jobs (10–15 windows) are completed within a day or two.

Yes, for heat loss especially. The sealed, argon-filled gap between the two panes significantly reduces heat transfer — our standard Optitherm® Low-E spec brings the U-value down to around 1.4, versus roughly 5.8 for the single glass it replaces. Standard double glazing gives a modest noise improvement over single glass, but if noise is your main concern — homes near busy roads, for example — our laminated acoustic glass option is better suited and gives a more noticeable reduction.

For most retrofits we use a Low-E coated pane paired with a clear toughened pane and an aluminium spacer bar — Optitherm®, which balances thermal performance with cost. For heritage frames needing extra acoustic performance, a laminated glass option is available. We'll recommend the right spec for your specific windows during the quote.

You can retrofit as few or as many windows as you like. Many clients start with the rooms that matter most — bedrooms for noise, living areas for heat — and expand later.

We're based in Banyule and service Melbourne's northern and inner-north suburbs, including Heidelberg, Eaglemont, Ivanhoe, Ivanhoe East, Northcote, Fitzroy, Brunswick and Kew, with heritage timber window restoration as a specialty. We'll travel further for the right job — give us a call if you're not sure.

It's not recommended. Removing original sashes without damaging the timber, correctly sizing and sealing the new IGU, and maintaining weatherproofing all require experience working with older frames. We bring 18 years of home maintenance and glazing background specifically suited to this kind of work.

Low-E stands for "low emissivity." It's a microscopically thin, transparent metallic coating applied to one of the internal glass surfaces inside the sealed unit. Rather than blocking light, the coating works like a thermal mirror — reflecting indoor heat back into the room in winter, and reflecting radiant summer heat before it gets in, all while letting visible light through as normal. We apply a Low-E coating across all of our glass options — standard, laminated and safety builds alike — so every retrofit gets this thermal benefit regardless of which spec suits your job, and it also helps reduce condensation on the interior pane. Combined with the insulating argon-filled gap between panes, this gives our standard Optitherm® spec its strong thermal performance — a U-value of around 1.4, versus roughly 5.8 for the single glass it replaces.

Yes, though not completely on its own. Low-E coatings are engineered to reflect both heat and UV radiation while letting visible light through, so a Low-E double-glazed unit blocks meaningfully more UV than standard clear double glazing — which helps protect carpets, furniture and artwork from sun fading over time. If UV protection is the priority for a particular room, our laminated acoustic glass option goes considerably further — the plastic interlayer bonding its two panes together absorbs UV radiation directly, and laminated glass built this way is generally understood to block up to around 99% of it, well beyond what standard glazing achieves. That also matters for anyone who spends a lot of time near a large window or glass door — a home office desk, a sunroom, a spot by the sliding door — since it meaningfully cuts the cumulative UV exposure that glass alone would otherwise let through.