August 22, 2026
Arched, trapezoidal, corner-turning, oversized — owners assess the visual result, contractors assess buildability, and the manufacturer knows that seven tenths of a non-standard project is decided at survey and detailed design.
Arched windows, trapezoidal units, corner-turning continuous runs, oversized floor-to-ceiling panels — once a project involves these, the owner is buying an effect, the contractor is buying buildability, and we as the manufacturer know where the risk really sits. An arch must be surveyed on site for radius and rise; an error beyond two centimetres and the drawing has to change. A corner window joins two units at an angle, and a wrong angle leaves a gap that no trim can hide. An oversized panel has to reconcile glass thickness, profile strength and hardware load capacity, and any miscalculation is a safety issue rather than an aesthetic one.
The most common failure mode on these projects is not that the window cannot be built. It is that information decays in transmission: the owner supplies a sketch, the contractor supplies an estimate, we receive a vague dimension, and the mismatch is discovered on site. Turning survey and detailed design into a signed document is the first and most critical step of any non-standard customisation. Our process begins with site measurement, not with a quotation.
A non-standard survey is more than width and height. The data set should include several width and height readings taken at upper, middle and lower positions — the minimum installable dimension rather than an average; the difference between the two diagonal measurements to establish squareness; wall plumb and flatness; the thickness of render and insulation layers; the condition of embedded items and fixing substrates around the opening; and the clearance required for the chosen installation method. For an arch, measure radius and rise or three-point arc data; for an irregular shape, measure every corner angle and produce a signed sketch on site.
Once survey is complete we issue a measurement record drawing for the owner or contractor to sign, and that drawing is the datum for all subsequent detailed design. Two traps recur in practice. The first is measuring to the finished surface when insulation and render are still to come — the allowance has to be built in beforehand. The second is assuming identical openings: we have seen a scheme with four corner windows at four different angles. Our engineers attend site with measuring equipment, check the record drawing against the contractor on the spot, and remove the argument before it starts.
An attractive render is not the same as a manufacturable window. Detailed design dismantles every item into something the process can produce. Panel division must be checked against tempering furnace and transport limits; profile sections have to be recalculated for wind pressure and span, with oversized panels requiring reinforced profiles or internal steel stiffeners; hardware must be re-specified for sash weight, with heavy hinges and multi-point locking above certain weights; the opening method needs adequate operating clearance and a drainage path; and glass thickness must be calculated from area and wind pressure, with argon filling and warm-edge spacers where the numbers demand them.
The output of this stage is a detailed construction drawing: profile sections and node details, panel division and opening types, a glass schedule (thickness, construction, Low-E and interlayer type, argon and warm edge), a hardware schedule, sealing and drainage nodes, and installation nodes with fixing methods. Our detailed drawings are produced by in-house factory engineers rather than through an intermediary, which means process problems are caught at design stage — for example, an irregular angle that would make vulcanising a gasket impossible, where the engineer will propose a revised panel division instead of discovering it on the shop floor. Every drawing carries a review record under our ISO 9001 system.
The core difficulty of a non-standard window is the manufacture of the irregular parts. Arches are typically produced by one of two routes. Profile bending heats the broken-bridge profile and forms it around a former, which suits larger radii and produces a continuous curve, but has limits on radius and material. Segmented polyline approximation builds the curve from many small angles, which accommodates tighter radii but leaves visible facets that the owner must accept at design stage. Curved glass can only be produced by heat bending or cold working, and very large widths bring tempering and coating limits of their own. Corner windows offer factory pre-assembly or site assembly: pre-assembly carries higher precision but stricter transport requirements, while site assembly is flexible but depends on installation skill.
We select the process according to project conditions and state the route and the expected visual outcome explicitly at detailed design. On profile bending, for instance, we issue the minimum bend radius and the arc tolerance, and where a project falls outside those limits we recommend the segmented approach rather than accepting the job and explaining afterwards. On glass, we confirm by area and curvature whether tempering and Low-E coating are achievable, and propose alternative glass constructions where they are not. Every process boundary is written into the confirmation sheet and signed by both parties before production begins.
Non-standard projects should be preceded by a sample window, for two reasons: to validate appearance — curve proportion, panel division, handle feel — and to validate manufacturing accuracy — diagonal difference, evenness of gaps, hardware fit. The sample can be judged at the factory, but installing one on the project building shows the result in context and is closer to the final condition. Production starts only after sample acceptance. This step appears to add time, but on a non-standard project it is the only real risk control: discovering that the curve looks unnatural at volume stage means reworking an entire batch.
Installation is the final gate. Arched and corner windows need more precise setting-out and fixing; the below-frame fill must be continuous and complete, and the lapping direction of the external waterproof membrane must be correct. We supply installation drawings and hardware schedules, and can send technical staff to site for technical guidance and first-unit acceptance, walking through the installation node and fixing method item by item. On larger commercial or industrial projects, on-site support substantially reduces rework. A non-standard customisation typically runs two to three weeks longer than a standard window, and in exchange delivers an effect matched to the architecture and a result installed correctly the first time.
Tell us your project scenario and requirements, and we will match the right solution and provide a quote within 24 hours.
Get a Free QuoteBroken-bridge aluminium profiles, insulated tempered / Low-E / laminated glass, full hardware-and-seal selection, detailed design from measured opening dimensions, support for non-standard sizes and shaped windows, 1-unit MOQ, U-value ≤1.8 W/(m²·K), 25–35 day delivery. ISO 9001-certified factory with 20 years of experience, providing wooden-crate / steel-frame reinforced packing, installation drawings, hardware lists, video guidance and dispatchable on-site technicians.
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