Heat and sound insulation
Double glazing for aluminium windows and doors
Double glazing puts two panes of glass in one sealed unit with a gap between them, and the insulation happens in the gap, not in the glass. That one point decides everything else about double glazed windows.
What is double glazing?
Double glazing is one unit made of two panes of glass held apart by a perimeter spacer that traps a layer of dry air or still gas, then sealed at the edge against moisture. The spacer holds a desiccant that absorbs any remaining moisture, and the whole unit fits into the aluminium profile like a single pane.
Double glazed windows are also called double pane or insulated glass windows, and they are the energy efficient choice wherever the sun hits the facade: the gap cuts the heat reaching the room and, with it, the air-conditioning load. The insulator is the trapped air, not the glass: still air conducts heat poorly while glass conducts it well, so a thicker single pane adds little, but a 12 mm gap between two panes makes a clear difference.
The sealed edge: the part that matters most and shows least
A unit lives by its edge seal: if it weakens, moisture enters the gap and the unit has to be replaced. So the quality of assembly matters more than any insulation figure. At handover, check for:
- A clean, even edge with no gaps in the sealant
- A straight spacer with no waves or breaks at the corners
- No trace of moisture between the panes, checked before installation, not after
- Sound drainage in the profile track, because water standing at the edge of a unit ruins it fastest
Does double glazing reduce noise, and what makes aluminium windows soundproof?
Yes, but less than many expect when both panes are the same thickness: identical panes vibrate at the same frequency, so that band of noise passes as if through one pane. What really improves acoustic performance is panes of different thickness, a wider gap between them and an airtight installation around the perimeter.
The weakest link is the perimeter: air leaking through a small gap at the walls carries sound faster than any pane. So soundproof double glazing depends on the whole installed window, not the unit alone: even double pane soundproof windows let noise in if the perimeter is not sealed. Where noise matters most, choose double glazed casement windows: a casement closes against its perimeter gaskets and seals tighter than a sliding window.
Single glazing vs double glazing
| Item | Single glazing | Double glazing |
|---|---|---|
| Build | One pane | Two panes with a sealed gap between them |
| Common total thickness | 4 to 8 mm | 18–24 mm in windows; 28 or 33 mm in curtain wall and structural glazing |
| Profile | Standard profile | A wider profile that holds the thickness and carries the weight |
| Heat transfer | Fast, as glass conducts well | Slower, as the still gap resists it |
| Noise | Passes almost freely | Reduced, more so with panes of different thickness |
| When to choose | Shaded openings, internal walls, tight budgets | Sun-exposed facades, busy streets, bedrooms |
Safety glass in specific positions follows the Saudi Building Code and the project specification.
Can you retrofit double glazing into existing aluminium window frames?
Rarely with success. When retrofitting double glazing into existing aluminium window frames, the obstacle is the unit itself: a double glazed unit is about four times thicker than a single pane, and a profile designed for 6 mm glass cannot hold its thickness or its weight. The result is a split track or overloaded hardware that lets the sash drop within months, so replacing the whole system is cleaner than adapting the old one.
That is why the glass and the profile are one decision, not two. On large facades, double glazing is specified within the facade system itself: see curtain wall.
Can double glazed doors be made in aluminium?
Yes. Double glazing goes into framed aluminium doors with a glass infill, sliding or hinged, on the same rule as windows: a wider profile that holds the unit and carries its weight, and hardware rated for the heavier leaf. It is chosen with the door type from the start and priced by quote. Double glazed patio, balcony, front and other external doors follow the same rule whenever they are framed aluminium doors with a glass infill. That includes double glazed sliding doors; for the sliding systems themselves, see sliding glass doors. There is no fixed double glazed doors price: for comparison, a two-track Royal sliding door starts from SAR 540/m² and a hinged door from SAR 585/m², both single glazed.
What goes into a double glazed window quote?
Double glazing is priced as part of the whole window, not alone: profile, glass, hardware and installation. As a double glazing supplier that also installs, we quote the unit, the frame and the fitting together, not supply and installation separately. In our aluminium windows it comes in the premium grade, 1.8–2 mm, at SAR 520–740/m² supplied and installed before VAT in Makkah, because the unit needs a profile that holds its thickness and weight. Your place in that range depends on:
- The unit thickness and the width of the gap
- Each pane: clear, securit (toughened), laminated, reflective or frosted
- The opening size and system: sliding, casement, tilt and turn or fixed
- The number of units in the order
Low-E glass carries a thin coating that cuts heat transfer while keeping daylight; it follows the project specification and is priced by quote. On glass facades, double glazing adds SAR 27/m² over single securit, and laminated double glazing SAR 200/m². Other cities add 3% to 10%. See all double glazing prices in our price guide.
Frequently asked questions
Why does mist appear between the panes of a double glazed window?
Because the edge seal has weakened, letting water vapour into the gap, where it condenses on the inner faces. The mist cannot be wiped away from either side because it is sealed inside the unit, so the whole unit has to be replaced.
Does double glazing reduce the air-conditioning load?
It reduces it on sun-exposed facades, because the still gap slows heat moving from the outer pane to the inside. Direct sunlight itself is cut by reflective or tinted glass in one of the panes, which is why the whole unit is specified in the quote, not the gap alone.
Is double glazing available in every grade of aluminium window?
No. In our aluminium windows, double glazing is offered in the premium grade only, with a 1.8 to 2 mm profile, because the unit is thicker and heavier than single glass. Economy and standard windows take single glass: clear, reflective or securit.
How much do double glazed windows cost per square metre in Saudi Arabia?
SAR 585–740/m², supplied and installed, before VAT, in Makkah. In our aluminium windows, double glazing comes only in the premium grade, whose 1.8–2 mm profile holds the unit's thickness and weight. The unit, the panes, the opening type and the order size set your place in that range, and other cities add 3% to 10%.
What gap is used in your double glazed windows?
A 6 or 12 mm air gap between a 6 mm tinted outer pane and a 6 mm clear or frosted inner pane. The wider 12 mm gap gives better thermal insulation, and the frosted inner pane adds privacy while still letting light through.
How long does a double glazed window order take?
Indicatively 12 to 16 working days from approved shop drawings to handover for an order under 50 m², and 17 to 23 for 50 to 99 m². The technical office confirms the schedule once the sizes and the unit specification are checked.
Can double glazed windows be tinted, frosted or Low-E?
Yes. Our double glazed windows pair a 6 mm tinted outer pane with a 6 mm clear or frosted inner pane: the tint cuts direct sun, and frosted glass gives privacy while letting light through. Low-E glass, whose thin coating cuts heat transfer, follows the project specification and is priced by quote. All sit in the premium grade, SAR 520–740/m².
Are you double glazing suppliers and installers for windows and doors across Saudi Arabia?
Yes. Qusoor Al-Sultan supplies and installs double glazed aluminium windows and doors from its factory in Makkah, quoting the unit, frame and fitting together. Windows come in the premium 1.8–2 mm grade at SAR 520–740/m² before VAT; framed aluminium doors with a glass infill are priced by quote. Other cities add 3% to 10% for transport and installation.
Related services
For the systems that take these units, see aluminium windows and sliding glass doors; for the glass itself, tempered glass. To stop the sun before it reaches the glass, see roller shutters or aluminium louvers.
Technical review: Eng. Hisham, factory manager at Qusoor Al-Sultan, with more than 20 years of management and technical experience in aluminium and glass. He reviews the technical content of this page. Last updated: 8 October 2026.