Aluminium picture windows

Insulation and sightline: the widest spread

Aluminium has the widest spread of any combination we carry: Uf from 0.57 to 2.35 and sightlines from 28 mm (the frame alone of the ConceptPatio 130) to 188.5 mm. That spread is the widest of any combination we carry, and it's because there are two lift-and-slide systems among them that you wouldn't normally choose for a window.

Maximum sizes and glass weight

For a fixed aluminium window the MB-Ferroline is the most interesting: a 97 mm sightline with a sash and 40.5 mm as fixed glazing, the slimmest of the Aluprof windows; the Reynaers CS 77 sits at 89 mm with a sash and the SlimLine 38 at 33.5 mm frame. On a fixed light, where there's no sash frame anyway, that gives the largest area of glass we can make. If you put insulation before lines, take the MB-86N at Uf 0.57.

Which profile should you choose?

Up to 6,500 × 3,000 mm. As with uPVC, the weight of the glass is the limit sooner than the profile; with large panes, check what can still be lifted and fitted. Delivery to the UK is quoted with your offer, and we supply, we don't install — getting a large pane into place is yours to arrange, and it's a real point to settle beforehand.

What you need to measure

Among the aluminium in the row above there are also sliding door profiles — the MB-59HS and the MB-77HS — and you'd only take those for a fixed light if the same run also has a sliding panel. What's left: the MB-Ferroline for the largest area of glass (97 mm sightline), the MB-86N for the lowest U-value (0.57) and the MB-79N if neither ties you.

Glazing bars and ventilation in the configurator

You're already two steps further than where the configurator starts. It first asks what the window is made of and then which profile, and that's exactly what you decide on this page. What it then asks of you is the size and the layout, the glass and the colour. For the size, measure the structural opening at three heights and three widths; the smallest figure is your size. A fixed window adds one question that doesn't come up with an opening one: how you'll reach the outside. Nothing opens, so cleaning happens from outside, and on an upper floor that's a recurring cost.

One more thing that counts and doesn't depend on the profile: Building Regulations. In England, Approved Document L asks a replacement window in an existing home for a U-value of 1.4 W/m²K or WER band B, for the whole window — so with aluminium too it's about the glass and frame together, not the material of the profile. Replacing windows is also notifiable building work: an installer registered with a competent person scheme, such as FENSA or Certass, notifies it, or you notify building control before the work starts. We supply, we don't install, so this is for your installer. Scotland and Northern Ireland have their own rules.

Of the nine choices in step 6, only two do anything on a fixed light, and it's worth keeping them apart. Glazing bars are the only one that touches the look: everything you see here is glass and frame, so a glazing bar is the only relief you can still add. On a slim aluminium frame that stands out more than on a wide uPVC frame — a 97 mm sightline with a glazing bar reads as a window with panes, not as glass with stripes. The trickle vent is the second, and it isn't a choice about looks but about use: a fixed light lets no air in, and if it's the only window in the room the air has to come from somewhere else. The other seven — window handle, cylinder, door handle, threshold, insect screen — belong to something that opens. The configurator still offers them, because the list isn't filtered by element type; here you simply leave them out.