Double Glazing Wollongong & Sydney
Retrofit double glazing and double glazed unit replacement for homes across Wollongong, the Illawarra and Sydney. Quieter, warmer, and installed to AS 1288.
Who Offers Retrofit Double Glazing in Wollongong and the Illawarra?
Level and Square Group installs retrofit double glazing and replaces failed double glazed units throughout Wollongong and the wider Illawarra. In most homes we can double glaze your existing windows without replacing the frames, which is faster, cheaper and far less disruptive than a full window replacement. Every unit is measured with the FlexiJet 3D laser system and manufactured to Australian Standard AS 1288.
Our glaziers work with homeowners, builders, architects and strata managers. From Thirroul to Shellharbour, we are known for accurate measuring, honest quoting and clean installation. If you are weighing up whether double glazing is worth it on the coast, we will tell you straight rather than sell you a full window replacement you do not need.
Retrofit Double Glazing
We double glaze your existing frames by replacing the single pane with a sealed double glazed unit. No new frames, no rendering or painting, and in most homes the job is done in a day.
Sealed Unit (IGU) Replacement
Sealed units fail eventually. When the seal goes, the unit fogs and stops insulating. We measure and replace the glass unit alone, leaving your existing frames and hardware exactly as they are.
Fogged and Failed Units
Condensation trapped between the panes means the argon has escaped and the unit is no longer performing. We replace fogged units with new sealed glass matched to your existing sightlines and finish.
Double Glazed Doors and Sliders
Sliding doors, stackers and French doors can all be double glazed. We handle the extra weight with the correct rollers and hardware so the door still runs properly afterwards.
Acoustic Double Glazing
If traffic or aircraft noise is the problem rather than heat, we specify asymmetric glass thicknesses and wider cavities. This makes a far bigger difference to noise than a standard double glazed unit.
Full Window Replacement
Where frames are rotten, rusted or beyond retrofitting, we supply and install complete new double glazed windows and doors. We will only recommend this when retrofitting genuinely is not viable. We have gone through the numbers in more detail in our guide to single glazed versus double glazed windows on the NSW coast.
Retrofit or Replace? What Your Home Actually Needs
Most Illawarra homes do not need new windows. If your frames are sound, retrofitting a sealed double glazed unit into them gives you the same thermal and acoustic benefit at a fraction of the cost and without touching your walls, architraves or paintwork. Timber, aluminium and uPVC frames can all usually be retrofitted.
Full replacement makes sense when frames are rotted, corroded, or too slim to take the depth of a double glazed unit. We assess this on site and tell you which applies before quoting. If retrofitting will work, we will say so, even though it is the smaller job.
What Does Double Glazing Cost in NSW?
Cost Per Window
The biggest cost drivers per window are the size of the pane, the glass specification, and whether the frame needs adapting to take the extra depth of a sealed unit. A small bathroom window and a large west-facing living room pane are very different jobs, so we quote per opening after measuring rather than working from a square metre rate.
Cost for a Whole House
Whole-house pricing is worked out opening by opening rather than as a flat figure. A home with two large sliding doors can cost more than one with eight small windows, which is why a per-window average is misleading. We measure every opening and give you a written breakdown so you can stage the work if you would rather start with the living areas.
Replacing a Failed Sealed Unit
Replacing a single failed or fogged unit is the cheapest job in this category, because the frame, hardware and sightlines all stay exactly as they are. You are paying for a replacement glass unit and the labour to swap it, not for a new window. Cost scales with the size of the unit and whether it needs a coating to match the panes around it.
Acoustic Upgrades
Acoustic units cost more than standard double glazing because they use thicker asymmetric glass, often with a laminated inner pane, and the frames sometimes need adapting to carry the extra weight. If noise rather than heat is the thing bothering you, this is where the money is worth spending.
Retrofit vs Full Replacement
Retrofitting is almost always cheaper than full window replacement, because you are paying for glass rather than glass plus frames plus making good. We quote both where it is a genuine choice so you can compare. For wider context on glass pricing, see our 2026 glass replacement price guide.
Why Double Glazing Performs Differently on the Illawarra Coast
Coastal homes have two problems that inland homes do not. Salt-laden air corrodes standard aluminium spacers and hardware faster, and the escarpment funnels wind and rain against south and east facing glass. We specify marine grade hardware and warm edge spacers on coastal jobs for exactly this reason, and we detail the drainage so water does not sit against the unit.
The second issue is what you are actually solving. On the coast, most people come to us about noise and condensation rather than heating bills. Those are different specifications. A unit that cuts your heating loss will not necessarily cut road noise, and we will ask which matters to you before quoting rather than after.
Want a Double Glazing Quote in Wollongong or Sydney?
Contact Level and Square Group for a measured double glazing quote across Wollongong, the Illawarra, the Southern Highlands and Sydney. We will assess whether your frames can be retrofitted, specify the right glass for noise or thermal performance, and give you a written price with no obligation. Send a photo of your windows to get started.
Does Level and Square Group Work With Strata and Insurance?
Yes. Double glazing in a strata building usually needs owners corporation approval, particularly where it changes the appearance of the facade. We provide the specifications, glass certificates and installation details your strata manager will ask for, and we are used to working to building access rules and approved hours.
Failed sealed units are sometimes covered under a builder warranty or home warranty insurance rather than a claim on your own policy. We provide the documentation either way, including the unit specification and the date of failure, so you can pursue it with whoever is liable.
Why Illawarra Homeowners Choose Level and Square for Double Glazing
Because we will tell you when double glazing is not the answer. If your heat loss is coming through an uninsulated ceiling or a draughty door, new glass will not fix it, and we would rather say so than take the job. Our reputation across the Illawarra is built on that kind of advice.
We are licensed, AGGWA accredited and every unit we fit meets AS 1288. We measure with the FlexiJet 3D laser system rather than a tape, so the units arrive right the first time and your frames are only open for as long as the install actually takes.
Double glazing is a long term change to your home. It is worth getting the specification right the first time rather than discovering in two winters that you solved the wrong problem.