Aluminium windows
Thermally broken aluminium frames that stay slim, take any colour and keep their looks for decades.
What is an aluminium window?
An aluminium window has a frame and opening sash made from extruded aluminium profiles. The inside and outside halves of the frame are separated by an insulating thermal break, and the whole thing is finished in powder coat. The thermal break is what makes modern aluminium windows different from the cold, dripping frames some people remember from the 1980s. With it, heat stays in and condensation stops forming on the inside of the frame.
Aluminium windows at a glance
- Frame: Extruded aluminium with a polyamide thermal break
- Finish: Powder coat in any RAL colour, with dual colour (one colour inside, another outside) available
- Glazing: Double or triple glazed sealed units with low-e glass and argon
- Opening types: Casement, tilt & turn, concealed sash, sliding and fixed
- Performance target: Whole-window U-value of 1.4 W/m²K or better
- Security: Multi-point locking, lockable handles and laminated glass options
Why aluminium?
More glass, less frame. Aluminium is much stiffer than uPVC, so the frames can be slimmer for the same size of window. On a big living-room window the difference in daylight is obvious.
Colour that lasts. A powder-coated finish is baked on. Dark colours like anthracite grey and black hold up in sun and rain without warping or peeling.
It doesn’t rot, swell or need painting. A wash with soapy water a couple of times a year is the maintenance. Do it more often if you’re near the sea.
It’s recyclable. Aluminium can be melted down and reused again and again without losing its properties.
To be fair to the other options: aluminium costs more up front than uPVC, and some people simply prefer the warmth of timber. We cover the trade-offs in more detail in our aluminium vs uPVC guide.
Aluminium window systems we fit
All of our aluminium windows are thermally broken and made to measure. The systems differ in frame depth, how much insulation sits in the thermal break, and how the opening sash looks from outside.
| System | Frame depth | Typical whole-window U-value | Best for |
|---|---|---|---|
| Standard | About 70 mm | 1.2 to 1.4 W/m²K | Most window replacements, double or triple glazed |
| High insulation | About 75 to 90 mm | Below 1.0 W/m²K with triple glazing | A-rated new builds and deep retrofits |
| Concealed sash | About 70 to 80 mm | 1.1 to 1.4 W/m²K | A minimal look: from outside, opening and fixed panes look the same |
| Slim steel-look | Narrow sightlines | Around 1.4 W/m²K | Period houses, red brick and industrial-style extensions |
U-values depend on the size of each window and the glass in it. Your quote names the system and gives the U-value for every window.
Finishes. Any RAL colour in smooth or textured powder coat, dual colour, wood-effect finishes and anodised aluminium.
Security. Burglar-resistant versions tested to RC2 or RC3 under EN 1627 are available, with laminated glass, reinforced hardware and concealed hinges.
Glazed walls. For glazed gables, stairwells and commercial fronts we also supply mullion-and-transom curtain walling: large fixed panes joined into one glass wall with slim 50 to 55 mm sightlines. See also our shopfronts and entrances.
Prefer a lower price and white or woodgrain frames? Compare our uPVC windows.
How we survey, supply and fit aluminium windows
- Survey. We measure each opening, check the reveals, sills and cavity closers, and agree which sashes open and which are fixed.
- Specification. Together we pick the opening styles, glass, colours and hardware. You get all of it in writing.
- Made to measure. The windows are built to the surveyed sizes and glazed before they come to site.
- Fitting. Old frames out, new frames in, one opening at a time. We fix and level each frame, insulate and seal the gap around it, and finish the reveals.
- Handover. We check every sash opens, closes and locks properly, and show you how everything works.
Choosing your aluminium windows
Colour. Anthracite grey (RAL 7016) is the colour we’re asked for most, followed by black and white. Dual colour is popular too, with grey outside to suit the house and white inside to suit the rooms.
Frame style. Standard profiles suit most houses. Slim “steel-look” profiles with narrow sightlines and glazing bars suit period renovations and modern builds that want a crisper line.
Glass. Low-e double glazing is the standard. Add acoustic laminated glass for road noise, solar control glass for big south-facing panes, and obscure glass for bathrooms.
Coastal homes. If you’re close to the sea, ask for a marine-grade pre-treatment under the powder coat. It costs very little extra and protects the finish against salt.
Aluminium window ideas
These are illustrations of design ideas, not photos of specific Brega Glazing jobs. See more in our ideas gallery.
Typical uses for aluminium windows
- Whole-house window replacement in older semi-detached houses, bungalows and farmhouses
- New builds and self-builds that want slim frames and dark colours
- Extensions where the windows should match new bifold doors or sliding patio doors
- Coastal and exposed sites where timber struggles
Aluminium window FAQs
Are aluminium windows cold?
Not modern ones. Today’s aluminium windows have a thermal break, an insulating strip that separates the inner and outer frame. Combined with good double or triple glazing, a quality aluminium window can reach a whole-window U-value of 1.4 W/m²K or better.
Do aluminium windows qualify for the SEAI windows grant?
They can. SEAI cares about performance, not material. The windows need a U-value of 1.4 W/m²K or better, your home has to meet the scheme’s age and insulation criteria, and the work must be done by a contractor on SEAI’s register. Check the current rules on seai.ie before ordering.
How long do aluminium windows last?
Well-made aluminium windows last for decades. The frames don’t rot or warp, and a good powder coat holds its colour for many years. The parts that wear are the moving ones: hinges, handles and seals. These can be adjusted or replaced without changing the window.
Can aluminium windows be a different colour inside and outside?
Yes. Dual colour is a standard option. A common choice is anthracite grey outside and white inside, but any two RAL colours can be paired.
How do I look after aluminium windows?
Wash the frames with warm water and a mild detergent two or three times a year, and more often within sight of the sea. Avoid abrasive pads and solvents. Once a year, clear the drainage slots at the bottom of the frame and put a drop of light oil on the hinges and locking points.