24/7 Emergency Glass Repair
Broken window, smashed door or a break-in. Board-up and make-safe any hour, glass replacement to follow.
Learn more →Why glass is where the heat goes
An uninsulated wall is bad; a single pane of glass is worse. Glass conducts heat readily and a window is thin, so a room with a large expanse of single glazing loses heat far faster per square metre than the wall around it. In a Melbourne winter that shows up as a cold spot near the window, draughty convection currents, and condensation streaming down the inside of the pane on a July morning. In summer, a west-facing single-glazed room under a northerly is unusable by four o'clock.
An insulated glass unit puts a sealed gas cavity between two panes. The cavity is the insulation. Add a low-emissivity coating on one internal surface and the unit also reflects radiant heat back where it came from — inwards in winter, outwards in summer.
What changed in Victoria
Victoria's building energy requirements for new homes and major renovations were lifted to a 7-star NatHERS standard, which is difficult to reach with single glazing on any meaningful window area. That has pulled double glazing from a premium option into a default for new work, and it has flowed into the renovation market, where people replacing windows anyway take the opportunity.
For existing homes nothing is compulsory. The reason people do it is comfort first, condensation second, and running costs third. Be sceptical of any quote that leads with a payback period — energy savings depend on how you heat, how leaky the rest of the house is and how much glass you have, and the honest answer is that most people notice the comfort long before they notice the bill.
The limits worth knowing
- The seal is the weak point. When an edge seal fails the cavity fogs internally and the unit has to be replaced. It cannot be dried out.
- Weight and thickness. Units are heavier and thicker than single panes, which is what makes retrofitting into old sashes a case-by-case assessment.
- Noise is a separate specification. Standard double glazing is not an acoustic product unless it is designed as one.
- It will not fix a draughty house. If the sashes rattle and the gaps around the frame whistle, sealing the frame matters as much as the glass. Draught-proofing plus reglazing sometimes beats a full unit on value.
- Heritage overlays bite. Across the inner suburbs the street-facing facade is frequently protected. The suburb pages note where this comes up most.
How the job runs
Site measure, assessment of whether the existing frames can take units, specification of glass and coating, then manufacture. Allow one to two weeks for units to be made. Where frames cannot take them, the conversation moves to window replacement instead.
Related pages: cut-to-size mirrors, glazed doors, and the cost guide for what moves the number.
More services
Explore our other services
Window Repair and Replacement
Reglazing timber and aluminium windows, plus custom awning, double-hung, sliding and louvre units.
Learn more →Shopfront Glass
Laminated shopfront panels, entry doors and after-hours board-ups so the shop still opens in the morning.
Learn more →Shower Screens
Framed, semi-frameless and frameless screens in toughened safety glass, made to the opening you actually have.
Learn more →Glass Splashbacks
Toughened 6mm splashbacks for kitchens, laundries and bathrooms, colour-matched and templated on site.
Learn more →Mirrors
Cut-to-size bathroom, wardrobe, gym and studio mirrors with polished or bevelled edges.
Learn more →Glass Balustrades
Frameless and semi-framed balustrades for stairs, balconies and decks, built to the fall height rules.
Learn more →Glass Roofs and Skylights
Overhead glazing, awnings and skylights in laminated glass, because overhead glass has its own rules.
Learn more →Pool Fencing
Frameless and semi-frameless glass pool fences built to the Victorian barrier rules.
Learn more →Glass Doors
Hinged, sliding, stacker and bi-fold glazed doors, plus reglazing the door you already have.
Learn more →Fly Screens
Pleated, sliding and fixed insect screens in extruded aluminium with PVC-coated mesh.
Learn more →Smart Glass
Switchable privacy glass that goes from clear to opaque, for partitions, consult rooms and bathrooms.
Learn more →Table Tops and Furniture Glass
Cut-to-size table tops, shelving and cabinet glass with polished, bevelled or pencil edges.
Learn more →Scratch and Graffiti Removal
Polishing scratched and acid-tagged glass instead of replacing it, where the glass can take it.
Learn more →
FAQs
Frequently asked questions
What is a double glazed unit, exactly?
Two panes of glass separated by a spacer bar, with the cavity between them sealed and usually filled with air or argon. The assembly is called an insulated glass unit, or IGU. The insulation comes from the trapped gas layer, not the extra glass, which is why the seal failing is the one thing that ruins the unit.
Can double glazing be retrofitted into my existing frames?
Sometimes. An IGU is thicker and heavier than a single pane, so the sash rebate has to be deep enough to take it and the sash and hardware must carry the weight. Many timber sashes can be routed out and rebalanced; many aluminium frames cannot take a unit at all without replacing the frame. It gets checked at the measure, not assumed.
Will double glazing stop condensation on my windows?
It greatly reduces condensation on the inside of the glass, because the inner pane sits much closer to room temperature. It does not fix the underlying moisture. If a house has unflued gas heating, a bathroom without a working exhaust fan or clothes drying indoors, the moisture simply condenses on the next coldest surface instead.
Does double glazing reduce traffic noise?
It helps, but less than people expect from a standard unit, because two panes of the same thickness resonate in a similar range. Real noise reduction comes from asymmetric glass thicknesses, a wider cavity, or laminated glass with an acoustic interlayer. If noise is the actual problem, say so at the quote stage so the unit is specified for it.
Am I allowed to replace windows in a heritage overlay?
Often not on the street-facing facade without a planning permit. Councils across inner Melbourne apply heritage overlays that protect original window profiles and glazing patterns, and swapping timber sashes for aluminium double glazing at the front is commonly refused. Rear and side elevations are usually treated more flexibly, and slimline units or secondary glazing are the usual answers at the front.
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