August 30, 2026
Most delay and rework on window projects does not originate in the factory. It originates in requirements that were never stated. A complete parameter list makes quotation accurate, scheme sound and acceptance provable.
Most delay and rework on window projects does not originate in the factory failing to build. It originates in requirements that were never stated. A client writes living room window, 2 metres by 1.5. The factory does not know whether that is the structural opening or the finished size, whether a fly screen is required, which floor and orientation it faces, or whether the room is on a busy street. So it quotes the most conservative scheme — reinforced profile, thicker glass, upgraded hardware. The price looks inflated and the client balks. Or it quotes the simplest scheme and the client is dissatisfied on delivery. Both deviations come from the same source: parameters that are not quantified enough to be unambiguous.
A complete parameter list solves three problems. Quotation becomes accurate, because glass construction, hardware model and profile series follow directly from the parameters and no risk allowance needs embedding. The scheme becomes appropriate, because insulated laminated for a street-facing bedroom and insulated Low-E for a sheltered room are only possible once environmental conditions are known. And acceptance becomes provable, because delivery is verified item by item against the list rather than judged by impression. The list below can be copied directly and trimmed to the project.
Dimension parameters must be stated to the millimetre and the basis must be explicit. Provide width and height of the opening with readings at upper, middle and lower positions rather than an average — installation uses the minimum clear dimension; both diagonal lengths and their difference to establish squareness; wall thickness and the thickness of render and insulation layers; the floor level and storey of the opening; sill height and whether the unit reaches floor level; and the condition of embedded items and fixing substrates. State whether dimensions are to the finished surface or the structural face, and whether render and insulation are included, because this determines directly how much allowance the manufacture size carries.
Arched, corner-turning and trapezoidal openings must be surveyed on site and signed off on a drawing. As a minimum provide radius and rise or three-point arc data, the angle at each corner, and the developed arc length. For oversized panels, supply the wind pressure data for the location or the relevant floor height and region, since glass thickness and profile strength must be calculated against it. On receipt we review the dimensions and return a confirmation drawing for written sign-off before production. Any later dimensional change follows a written process; verbal amendments are how batches get scrapped.
The opening type determines hardware and the daily experience, not just the drawing. For each unit state: the opening type (fixed, inward opening, outward opening, tilt-and-turn, sliding, lift-and-slide, top-hung), the opening direction, locking requirements, whether a fly screen is needed (fixed or removable, mesh type) and whether restrictors are required for child safety or fall prevention. On function, state the room use (bedroom, living room, kitchen, bathroom, retail, factory) and the priority: noise, insulation, ventilation, security, weather protection.
Functional priorities need to be specific enough to act on. Noise priority is not enough on its own; state the source — main road, rail, plant room — and the improvement expected. Thermal priority is not enough; give the local winter minimum temperature or the whole-window U-value ceiling expected. These details decide whether the glass is insulated or insulated laminated, whether argon is filled, and whether Low-E is high-transmission or low-emissivity. Residential projects should describe rooms individually rather than applying one configuration throughout the dwelling.
Performance indices are best stated as numbers that can be accepted. Whole-window U-value ceiling, for example 1.8 W/m2K or below; airtightness and water-tightness grades; wind-load resistance grade by floor and region; acoustic requirement such as weighted sound reduction RW of 35dB or above; and whether safety glass is required (lower floors, large areas, canopies). On material configuration, specify profile series and wall thickness requirement, thermal break strip material (PA66), glass construction (thickness, layers, Low-E film position, argon filling, interlayer type and thickness), warm-edge spacer requirement, hardware brand tier or load requirement, and colour with surface treatment (same colour inside and out, powder coat or fluorocarbon).
Every one of these entries maps to a process decision. The Low-E film position, for instance, materially changes thermal performance if it is wrong. The interlayer choice between PVB and SGP differs by an order of magnitude in stiffness and impact resistance, which matters on large panes. We return each of these parameters line by line in our quotation, so the customer verifies one document that both parties stand behind, and acceptance samples against that list — transparent and traceable.
The last group decides whether the scheme can be executed on site, and is the one most often omitted. Provide lifting and transport conditions on site — lift dimensions, corridor width, lifting equipment available — because these decide whether units ship assembled or require site assembly; who is responsible for installation (main contractor, specialist subcontractor or owner), which drives the choice of node detailing; whether waterproofing and insulation around the opening are complete, which determines how the external membrane laps; the construction programme and the desired site arrival date; and the project location and delivery method (sea port, inland city, whether pallets and multiple transfers are needed).
The clearer these nodes, the more controllable the programme. Our standard process is: on receipt of the parameter list we issue a detailed scheme and configuration proposal, and after customer confirmation we release production; standard configurations complete in 25-35 days, packaging is tailored to transport distance and container type, and the goods ship with installation drawings, hardware schedules, glass test reports and installation video guidance, with optional technical staff to site for first-unit acceptance. If you do not yet have a list in this form, start filling the four groups above — or send us the architectural drawings and site photographs, and our engineers will help assemble them into a complete technical parameter list.
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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