The window shapes most fitters turn down

Why standard measuring doesn't work

A rectangular window is defined by four straight lengths. An arch, circle or raked top is defined by a curve or an angle that a tape measure cannot capture accurately enough for a panel to fit flush against it. Get the curve even a few millimetres wrong and the shutter either won't close against the frame or will leave visible gaps.

Templating: the actual process

For a genuinely curved or irregular opening, we take a physical template of the exact shape on site, usually using a flexible material pressed directly against the reveal, rather than relying on measurements alone. That template travels with the order so the shutter is manufactured to the true shape of your specific window, not a standard arch radius.

Arched windows

Full arches, above front doors or as feature windows, are usually shuttered with a fixed arch panel that follows the curve, paired with operable louvred panels below for the square section of the opening. This gives light control where you actually need it while keeping the arch itself intact and undivided.

Circular windows

Circular windows, common in stairwells and gable ends, are one of the more specialist jobs we take on, since the entire panel is a single templated shutter with no straight edges at all. These are usually fixed louvre or solid panels rather than fully operable, because a hinge and frame system does not translate well to a full circle.

Angled and raked tops

A window with a flat bottom and an angled or raked top, often found where a window follows a sloping ceiling or gable roofline, needs the top section templated individually even though the lower section may be a standard rectangle. We frequently shutter these as a combination: standard operable panels below, a fixed shaped panel above.

Half-moon and eyebrow windows

A half-moon or eyebrow window, sitting above a larger rectangular window rather than as a standalone feature, is templated the same way as a full arch but is usually left as a single fixed panel rather than paired with operable louvres below, since there is rarely a lower square section to dress separately. These are common above front doors in both period terraces and some new build porches, and the template has to account for the fact that the curve is frequently shallower and wider than a true arch.

Full gable end windows

A full-height gable window, running from a low sill right up into the apex of the roofline, combines several of the challenges above in one opening: a raked top, sometimes a curved section, and considerable overall height. These are templated in sections, usually a shaped fixed panel at the apex and standard operable panels running down the straight sides, so the finished shutter still gives usable light control at a height you can actually reach, rather than leaving the whole window as one very tall fixed piece.

What this means for cost and lead time

Templated shapes take longer at the survey stage and longer in manufacture, since nothing about them is off-the-shelf. It is honest to say they cost more per square metre than a standard rectangular window of the same size, purely because of the extra time involved at both ends.

• A physical template is taken on site for genuinely curved or irregular openings
• Arches are usually a fixed curved panel above operable louvred panels below
• Full circles are typically fixed or fixed-louvre rather than hinged
• Angled or raked tops can often combine a standard lower section with a shaped upper panel