2-pane fixed window, made to measure

Where a single fixed window stops at one pane, this window adds a second fixed pane beside it, with a mullion between. Both panes stay fixed: no hinge, no handle, and so no hardware to maintain. That makes this the form for a wide opening where you mainly want light and a view out, and handle ventilation elsewhere in the room — at a door, or at another window in the same space.

The standard size is 1,800 × 1,500 mm, split equally between the two panes. If you do want to open part of the same width, the 2-pane window with one tilt and turn sash — one fixed pane and one tilt and turn pane — or the 2-pane window with two tilt and turn sashes — two tilt and turn panes meeting in the middle — is the form that provides for it.

This window works well where you're mainly after the view out without a sash breaking up the picture: a living room looking onto the garden, a bay, or an elevation where you want the calm of one unbroken pane of glass either side of the mullion. Because there is no hardware in it, this is also the form that needs the least maintenance of all 20 layouts in this group — there is simply nothing that can drop or needs replacing.

Within the row of double windows (the 2-pane fixed window, the 2-pane window with one tilt and turn sash, the 2-pane window with two tilt and turn sashes), this is the cheapest and the form with the least frame in view, because no sash profile is added. The step up to the 2-pane window with one tilt and turn sash costs you one set of hardware for ventilation on one side; the step to the 2-pane window with two tilt and turn sashes costs two, but also gives you access to clean on both sides. Which of the three fits depends on how much ventilation you expect to need in this one spot.

When you order, measure the full width of the opening in one go; the configurator divides it between the two panes as soon as you enter the size, with the mullion where you specify. Because there is no sash in it, no clear swing space is needed — so this window can go right up to a corner of the elevation or an adjoining wall, which is harder with an opening pane.

Of all the double windows, this one needs the least maintenance: no hinge, no locking hardware, just glass and frame either side of the mullion. Colour and finish follow the same chart as any other pane — any RAL colour on aluminium, a foil or through-colour on uPVC — and because both panes are identical and fixed, there is no reason to give them different colours; the window looks calmest as one continuous area of colour with only the mullion breaking it.

When a living-room wall is renovated, this window often replaces two separate, older windows with one continuous area of glass, which widens the view straight away without making the opening itself wider. In a new build this wide, fixed form is often used as the backdrop for a bay or an extension, where the architect deliberately goes for as much glass and as little visible frame as possible.

For break-in resistance, both panes are fixed and so harder to force than an opening pane — there is no hardware anywhere to get a grip on, only glass. On the ground floor, laminated or safety glass is where you gain any extra resistance.

Because both panes are fixed, you can use the heaviest, best-insulating glass across the full width with no consequences for hardware. That makes this window a logical choice if insulation counts for more than ventilation in this particular spot.

Still not sure? Use the comparison with the other layouts in this group above to see which arrangement suits your situation best.