Arched window detail with multi-pane divided lites in a stone facade

Differentiator

Specialty shape windows

A specialty shape window is any window outside the standard rectangle: arched, round, oval, half-round, quarter-round, trapezoid, eyebrow, fan, or a fully custom form drawn for a specific elevation. Crateworks builds these in thermally-broken aluminum to the opening on your plans, with the same slim frame and any RAL color, shipped direct.

Positioned for renovation and replacement projects. We confirm operability, size, glass spec, and any required certification in writing before order.

Shapes Crateworks builds

Arched windows

A full-height window with a rounded top, often set above a rectangular sash or as a single tall unit. Common above front doors, on stair landings, and in transitional and traditional architecture. Built to your radius and rise.

Round windows

A circular window. A gable accent on a traditional facade, a porthole on a coastal home, or a focal point on a stair landing. Crateworks builds round windows fixed, with a slim aluminum frame holding the full circle in one piece.

Oval windows

An elongated circle, set horizontally or vertically. Reads softer than a round window and works well between floors on a stairwell or above a sink where wall height is limited.

Half-round windows

A semicircle, the top half of a round window, usually set above a rectangular window or door as a transom. The classic Palladian element, in slim aluminum instead of wood or PVC.

Half-moon windows

Another name for a half-round, used interchangeably in residential work. Some manufacturers reserve half-moon for a flatter arc; Crateworks builds either profile to your rise.

Quarter-round windows

A quarter of a circle, set in a corner to round off a rectangular window above or below. Used to break the line of a tall stack of windows or to fit a sloped roof condition.

Trapezoid windows

Four straight sides with the top edge sloped to match a roofline. The standard solution for a window under a gable or shed roof where a rectangle would leave a triangle of drywall above.

Eyebrow windows

A shallow arched window, wider than tall, often set into the eave of a roof as a daylight feature. The arc is broad and gentle, like a brow.

Fan windows

A half-round window divided into radial muntins that radiate from the center of the chord, like a fan. The signature transom over a Georgian or Federal door.

Custom shapes

Triangular, pentagon, hexagon, octagon, ellipse, raked, or one-off shapes drawn for a specific elevation. Crateworks builds to the architect's drawing, with the aluminum frame mitered or curved to suit. Minimum order applies on highly custom shapes.


Why aluminum on a specialty shape

A round, arched, or angled window is harder to build than a rectangle. The frame has to carry a curve or a miter cleanly, and the glass has to follow. Aluminum extrusions bend and mitre to tight tolerances without the warping that wood develops over a curve, and a baked finish holds across the shape without breaking at the joint. The result is a specialty shape that reads as one continuous frame, not a stitched-together approximation.

Pairing with rectangular windows

Specialty shapes usually live above or beside a rectangular window or door, like an arch on top of a casement or a trapezoid above a slider. Crateworks builds both pieces in the same profile system and the same finish, so the combination reads as a single window with a shaped top, not two separate units stacked. Specify the opening with both pieces and we quote them together.


Common questions

A specialty shape window is any window outside the standard rectangle. Arched, round, oval, half-round, quarter-round, trapezoid, eyebrow, fan, and fully custom forms are all specialty shapes. They are common in transitional architecture, on stair landings, above doors, and in gables, and they are made to the opening rather than pulled from a stock size catalog.
Most specialty shapes are fixed, because operable hardware does not fit neatly into a curved or angled frame. Trapezoids and large rectangles with a small arch on top sometimes split into a fixed top and an operable bottom. Crateworks confirms what is operable for a given shape when we quote it.
Yes. Crateworks aluminum profiles are the same across shape variants, so an arched top set above a rectangular sash reads as one continuous frame and color. The frame is mitred or curved to the shape, and the finish matches across both pieces.
Specialty shapes typically run the same custom-order lead time as a rectangular window, since both are built from the same profile system on the same line. Highly custom one-offs may add time for tooling; we confirm the schedule before we accept the order.
Glass and frame both have practical limits. Very large round and arched windows require thicker glass and a deeper frame to carry the load. The right size for your opening depends on the wall, the glazing, and the location. Send the opening and we will confirm what is buildable.
Yes. The aluminum frame on a specialty shape carries any RAL color the same way a rectangular window does. Black is the most requested, white is common, and bronze and anthracite are both popular on heritage and modern facades. The color is a baked-on finish applied before shipment.

Built to order

Specialty shape, to your opening.

Send the opening dimensions or an elevation drawing. We confirm the shape, the glass, and the lead time, then build to it.