When a buyer asks a window manufacturer "what is your production capacity?", the honest answer is not a number. A custom aluminium window is not one process that happens faster when the building is bigger. It is a chain of independent processes, and the question that matters is which link sets the pace for your order, at your specification, in your colour batch. This article explains what "production capacity" actually measures for an aluminium window maker, what casement window manufacturer ALPES publishes about its own operation, and the questions that turn a vague capacity claim into something you can verify before you commit a project.
ALPES publishes a clear headline figure: a 100,000 m² manufacturing facility spread across two production centers in Foshan and Zhaoqing, Guangdong, China. That number is real and useful, but it is also the weakest signal of throughput you can ask for. Square metres of roof tell you about real-estate and headcount ceilings, not about how many correct windows leave the dock in a month.
The reason is simple. A window passes through profile supply, thermal-break assembly, surface finishing, fabrication, glazing, hardware fitting, assembly and quality control, then packing and freight. Each of those is a separate capacity with its own bottleneck. A large floor area does nothing if the slowest of those steps is a single powder-coating line or a single glazing cell. So the right first move is to stop asking for one number and start mapping the chain.
Here is the chain for a thermal-break aluminium window, and what constrains each stage. Where ALPES publishes a specific fact, it is stated; where it does not, the line is marked as something to ask for rather than assumed.
| Stage | What it actually is | What constrains it | What ALPES publishes |
|---|---|---|---|
| Profile supply | The aluminium sections the whole product is built from | Whether the maker extrudes in-house or buys; alloy and wall thickness | 6060-T66, wall 1.8–2.5mm. In-house extrusion not published — ask |
| Thermal break | Rolling the polyamide strip that cuts the heat path | Strip width and chamber count per series | PA66GF25 multi-chamber strip used across the range |
| Surface finishing | Powder coating the visible faces | Single-batch colour match across a whole project | Standard colours (Ice Cream White, Aurora Gray, Starry Sky Gray, Brown Coffee); custom match available |
| Fabrication | Cutting, corner assembly, reinforcement | Corner method; tolerance control on long runs | Injection-moulded structural adhesive corners, reinforced corners |
| Glazing | Building the insulated glass unit | Cavity size and gas fill per configuration | 24A and 27A cavities with inert gas options |
| Hardware fitting | Locks, hinges, transmissions | Named brands and per-series compatibility | ROTO, Winkhaus, CMECH, Wehag — German and named |
| Assembly & QC | Final build, sealing, checks | Sampling rate and test depth | Full-perimeter sealing; specific tests published for some series |
| Packing & freight | Crating, moisture protection, loading | Sea-worthy crating discipline on large orders | Not published as a standard — ask for the crating spec |
On a small order, almost any stage can be the limiter, and it rarely matters. On a large order — two hundred matching units for one villa development, say — the binding constraint shifts to the slowest single-unit step or the tightest quality gate. Very often the real ceiling is not floor area at all; it is the largest single colour batch the coater can guarantee to match, or the glazing cell's daily output of one specific cavity. A 100,000 m² plant that can only hold one colour consistently across a fraction of that area has, for your project, a much smaller effective capacity than the headline suggests.
ALPES has not published a monthly output figure, and this article will not invent one. The useful move is to ask for throughput tied to your configuration, not to a generic plant. A number quoted without your glass build-up, your colour, and your hardware is decoration.
| Published by ALPES | You still need to ask | Why the gap matters |
|---|---|---|
| 100,000 m² facility, two centers (Foshan, Zhaoqing) | Monthly throughput at your spec | Area is not output; the chain sets the pace |
| 6060-T66, wall 1.8–2.5mm | Do you extrude, or source? | Own extrusion shortens lead and protects supply |
| PA66GF25, named hardware (ROTO, Winkhaus, CMECH, Wehag) | Largest single colour batch guaranteed | Whole-project colour consistency depends on it |
| K as low as 1.3 (AW90), 1.6 (C120), 1.7 (C116) | K value for your glazing build-up | Published K is a system value, not your window's value |
| Full-perimeter sealing; specific tests on some series | QC sampling rate and test depth | "We check every one" is not verifiable without a written AQL |
ALPES is a project-driven, made-to-order manufacturer rather than a catalogue stockist. That means "capacity" includes a second, quieter meaning: how much engineering work the plant can absorb without the drawings becoming the bottleneck. Reading architectural submittals, producing shop drawings, holding tolerances across series whose frame wall widths run from 90mm (AW90) to 182mm (SL182), and turning a bill of quantities into a cut list — all of that is work that competes for the same calendar as the factory floor.
A useful honesty note for planners: the aluminum sliding window supplier side of the catalogue — the TS130 side-press window and the SL sliding-door family — does not publish a whole-unit U or K value. The 1.3 / 1.6 / 1.7 figures belong to the AW90, C120 and C116 opening families, not to the sliding family. So when you size a project's thermal performance, ask for the value computed for the exact sliding configuration you specified, not the figure from a different opening type.
The Foshan and Zhaoqing locations are not just a way to add square metres. Two centers mean load can be balanced when one line is full, and a single local disruption does not stop the whole order. For a buyer, the practical read is: ask which center builds your series, and whether a second center can take overflow if your volume spikes. Redundancy is a capacity feature that a single impressive building cannot provide.
If you want to know how much a plant can actually deliver, watch its lead time under load, not its brochure. As a planning reference — these are widely published industry guidance figures, not an ALPES commitment — custom windows and doors commonly run about six to sixteen weeks, with the frame-ordered window often quoted around eight to twelve weeks, and buyers advised to place the order three to four months before the framing stage. Treat any number your supplier gives as valid only when it is tied to your bill of quantities and written into the contract.
| Ask | A good answer looks like | Red flag |
|---|---|---|
| Do you extrude your own profiles? | Yes, with mill certificates — or an honest "we source 6060-T66 from X" | "Fully integrated" stated with no mill certs offered |
| Throughput at my spec? | A number tied to your glass, colour and hardware | "Unlimited", or a round number with no configuration |
| Largest single colour batch guaranteed? | A documented batch size, with batch number recorded per unit | "All match" with no batch-tracking system |
| Lead time at my volume? | Quoted per your BOQ, in writing | "Same as a small order" |
| QC sampling rate? | A written acceptance level and test method | "We check every one" with no procedure |
| Sea-freight packing standard? | Documented crating and moisture protection | Vague, or "standard export packing" only |
1. Is a bigger factory always better? Not for your project. The relevant capacity is the slowest step in your specific chain, not the total building area.
2. Why does colour come up so often? Holding one colour consistent across hundreds of units is a finishing-line constraint that floor area does nothing to fix.
3. Does in-house extrusion matter? It shortens lead time and protects supply during shortages, but the alloy and wall thickness (6060-T66, 1.8–2.5mm) matter more than the ownership label. Ask for mill certificates either way.
4. What does "custom" do to capacity? It adds engineering throughput — drawings, submittals, cut lists — which competes with floor time for the same calendar.
5. Can two centers really help? Yes — load balancing and redundancy mean a spike or a local disruption does not stop your order.
6. How do I verify a capacity claim? Ask for throughput at your specification, a written lead time per your bill of quantities, and a documented QC and packing standard. A claim you cannot trace to your order is not a commitment.
For project-specific capacity and lead-time figures, contact the engineering team directly through the china casement glass window factory quotation channel with your bill of quantities.
