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Fixed triangular aluminium window in the gable apex under a pitched timber ceiling in a Dubai villa, palm crown against blue sky through the three-sided glass
  • GABLES AND APEXES
  • FIXED FIELD

Triangular windows

Everything difficult about a triangle lives in its sharp corner. Where two profiles meet at a narrow angle there is very little metal left to make a joint in, the gasket has to be worked round a point instead of a right angle, and the pane finishes in a tip that must be ground before it goes anywhere near a furnace. So triangles are built as fixed fields, mitred and sealed on the bench rather than assembled in the opening, and the drawing keeps that acute corner as blunt as the elevation will allow. They appear wherever a roof does — a gable over a double-height hall, the apex above a stair, the closing piece at the top of a raking run of glazing.

  • the acute corner what limits the shape
  • mitred on the bench how it is built
  • dressed, then hardened the glass tip
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Where a triangle is decided

  • Sharp corner

    Weak point

    Least metal to make a joint in

  • Mitred and sealed

    Assembly

    Closed before it leaves the works

  • Round the point

    Gasket

    Worked, never cut and butted

  • Ground tip

    Glass

    Edge dressed before toughening

  • Fixed

    Opening

    The vent sits in the field below

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Three-storey villa with panoramic aluminium glazing and a branded Aluminum Windows car in the driveway
The same villa drawn as a pencil sketch — the design stage of the glazing project

Why choose aluminium windows?

  • Aluminium window profile cross-section with three EPDM seal contours highlighted in red

    Durable EPDM seals

    Three contours of EPDM seals keep the glass off the aluminium and close the gap between sash and frame, so dust, humid salt air and wind-driven rain stay outside.

    Learn more
  • Aluminium window profile cross-section with a foamed thermal insert highlighted

    Foamed thermal inserts

    Foamed inserts fill the profile chambers and stop air circulating inside them, so less outside heat and street noise passes through the frame into the cooled room.

    Learn more
  • Aluminium window profile cross-section with polyamide thermal breaks highlighted

    Polyamide thermal breaks

    Glass-filled polyamide thermal breaks up to 40 mm wide keep the outer and inner shells apart, so the frame holds its shape and its insulation through a UAE summer.

    Learn more
  • Aluminium window profile with an energy-efficient double glazing unit highlighted

    Energy-efficient double glazing

    Double glazing up to 60 mm thick puts a sealed gap of still air or gas between the hot street and the cooled room, so less heat crosses the glass into the room.

    Learn more

How a triangular window is measured and made

  • All three angles taken on the built opening Roof pitches drift from the drawing
  • Longest edge and its level checked The base sets everything above it
  • Acute corner opened where the design allows A blunter tip is a stronger tip
  • Frame mitred and sealed in our Dubai factory Corners closed on the bench
  • Pane cut to shape, dressed and toughened The tip is the fragile part
  • Set, packed and glazed once the frame is true The apex sealed last

Partitions

Office partitions made of aluminium profiles are a simple, quick, and cost-effective way to organise efficient zoning within a large space, while maintaining interior unity.

The honest downside

Before you glaze the gable

A triangle high in a gable is glass you will rarely touch. It sits fixed above a double-height hall or a stair, and washing it from inside usually means a tower or a long ladder; in a sandy week the dust on it simply stays there to look at.

It gives less than it seems, too. The tip that makes the shape holds very little glass for a lot of frame, and it is the weak point — the part that asks the most care in making and cannot be adjusted once set. Off-the-shelf blinds rarely fit it.

Where the room needs the light more than the shape, leaving the apex solid and glazing a rectangular field lower in the gable gives glass you can reach, open beside and shade. A triangle stays the right answer where the gable is the feature and the full shape is what the elevation is about.

Consider instead Fixed windows

Frequently asked questions

Because window hardware is built for parallel stiles and square corners. A hinge needs a flat edge, a multi-point lock needs a straight run to throw its cams along, and a triangle offers one usable edge at most. Rather than force gear into a shape that fights it, we glaze the triangle as a fixed light and put the room's ventilation into the rectangular field beneath it, which is where a hand can reach a handle anyway.

It can, provided it is never made on site. At a narrow angle the two profiles overlap in a long thin mitre with very little section left, so the joint is cut, bonded and sealed under bench conditions and the corner is proved before the frame is loaded onto a vehicle. Where the elevation lets us, we also ask the architect for a slightly blunter apex — a few degrees of extra angle puts a surprising amount of metal back into the joint.

It can, for two reasons that are easy to design around and easy to ignore. Glass high in a gable stays in the sun after lower windows have fallen into shade, and the warm air it produces has nowhere to go under a pitched ceiling. Solar-control glass in the triangle deals with the first; an opening leaf placed low in the same room deals with the second by giving the stratified air a path out.

It is common, and it is the reason we measure all three angles instead of one pitch and a mirror. An asymmetric triangle is no harder to make than a symmetrical one — the cutting list simply carries three different figures — but it is impossible to fix afterwards, because there is no adjustment in a fixed field. The survey is where that gets caught.

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Dubai — Showroom

The Pinnacle Building, Sheikh Zayed Road, Office 607

Mon–Fri: 9:00 – 18:00

+971 50 220 6913

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Samples to see in person

Profiles, glass units and hardware to see and touch before you choose.

Dubai — Showroom The Pinnacle Building, Sheikh Zayed Road, Office 607
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