Methodology, evidence policy and corrections

What this site covers

Finished aluminum windows and doors, upstream window profiles and extrusion, and the procurement process around them: RFQ, MOQ, inspection, packing, shipping, landed cost and platform comparison. The geographic focus is Foshan and Dali in Nanhai District. There is no separate Nanhai page because this edition does not have enough distinct, sourced material for one.

How evidence is handled

Factual statements are attached to a claim record. A claim has a statement, an evidence type, one or more citations, a verification date, a confidence note and explicit limitations. Platform badges, supplier FAQ figures and catalogue claims are treated as supplier or platform statements unless an independent document was actually reviewed.

A listing price is not converted into a site price. A profile wall thickness is not converted into a quality verdict. A certification logo is not converted into proof that the ordered model, size and glazing configuration will meet a destination requirement.

Where the record is incomplete, the page uses Not verified, To be confirmed or an explicit empty state. Those labels are deliberate, not placeholders to be filled with plausible numbers.

No field visits are claimed

This edition is desk research. No market walk-through, factory audit, interview or sample inspection has been performed. The city pages render an empty local field-note module, and the data file for first-hand records contains zero published entries. When a real visit is recorded, it will carry an observer, date, location precision, permission status and review decision before it can appear.

Price and MOQ policy

Public listings are sampled only when the listing text, date, unit, currency and missing configuration can be recorded. A sample is shown as a dated observation, never as a category range. One Alibaba profile observed on 10 November 2026 is retained on the sliding-window page; its title mixes “vertical sliding” and “single hung”, and it does not state glass build-up, hardware, Incoterm or quantity basis.

MOQ is not assumed. A single supplier FAQ stating “100 units per model” says nothing about another supplier, another model or a custom size. Where no sample exists, the answer is Not verified.

Independence and conflicts

This site sells no products, holds no stock and receives no commission from the suppliers or platforms mentioned. External links go to public pages; they are not affiliate links. A supplier profile appearing in a source list is not an endorsement, ranking or recommendation.

Corrections and review schedule

Platform rules, prices and freight assumptions get a short review cycle; stable technical definitions get a longer one. Each page shows its next scheduled review date. If a source disappears or contradicts a recorded claim, the claim is marked disputed or expired and the affected sentence is revised or removed rather than silently overwritten.

Corrections should cite the page, the sentence and a public source. This static edition has no contact form; the source data and build script are the correction record for the next build.

People behind this edition

• Research Editor (researcher). Desk researcher for this edition. Compiles public sources, records claims and limitations, and maintains the review dates. Not a factory auditor or licensed engineer.
• Technical Reviewer (technical reviewer). Reviews terminology, units and claim wording against the cited public references. Does not certify supplier products or destination compliance.

Roles describe research responsibilities. No engineering licence, factory audit qualification or local residency is claimed.

Sources used across the edition

• Forge Windows and Doors (FoShan) Co., Ltd. supplier profile — Alibaba.com, accessed 10 November 2026. Limits: Company statistics and FAQ answers are supplier-provided or platform-collected and were not independently audited for this edition; A platform badge does not establish that a specific order will meet destination performance requirements.
• Foshan Uhouse supplier showroom — Made-in-China.com, accessed 10 November 2026. Limits: The URL returned HTTP 403 on 2026-11-10 and its content could not be reviewed for this edition; No product, capacity or price statement from this page is used as evidence.
• WANJIA high-end door and window product guide (PDF) — wanjiadw.com, accessed 10 November 2026. Limits: The PDF could not be machine-read during this build, so its detailed claims were not used; Catalogue descriptions are self-published and do not verify production capability.
• Thermal insulation — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia overview, not a standard or test method; The page redirects to the broader Thermal insulation article and is not specific to window frames.
• 6063 aluminium alloy — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia summary of secondary sources, not the Aluminum Association standard itself; Property values depend on thickness, temper condition and product standard; they cannot be used as acceptance limits without the applicable specification.
• Anodizing — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia overview, not a coating specification or inspection standard; Typical thickness ranges in the article are not acceptance criteria for a particular order.
• Powder coating — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia overview, not a coating specification or warranty document; Cure schedules and film thickness values in the article vary by powder system and are not order criteria.
• Extrusion — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia overview, not an extrusion tolerance or alloy standard; Process temperatures and equipment descriptions are general and not supplier-specific.
• Foshan — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia summary; population and administrative details should be checked against current official sources before publication decisions that depend on them; The article does not establish supplier capability or current factory locations.
• Dali, Guangdong — Wikipedia, accessed 10 November 2026. Limits: Encyclopedia entry, not a government or industry-association cluster report; The industry sentence is unsourced on the page and is treated as a low-confidence lead, not a measured cluster statistic.
• Build and submit a sitemap — Google Search Central, accessed 10 November 2026. Limits: Search-engine documentation changes; the accessed date is recorded; Guidance does not guarantee indexing or ranking.
• Spam policies for Google web search — Google Search Central, accessed 10 November 2026. Limits: Policy text is summarized, not reproduced in full; Policy interpretation is not legal advice.
• Product structured data — Google Search Central, accessed 10 November 2026. Limits: This edition does not emit Product structured data because it has no real offers, reviews or aggregate ratings; Eligibility rules can change.
• Incoterms rules — International Chamber of Commerce, accessed 10 November 2026. Limits: The overview does not reproduce the full rule text or the allocation of costs for each term; The current edition and named place must be confirmed in the contract.
• Editorial research log for the 10 November 2026 edition — Foshan Aluminum Sourcing, accessed 10 November 2026. Limits: This is an editorial process record, not a third-party audit; It is published as a statement of method and does not contain private notes or personal data.

Indexing policy

Only published pages with an index policy, a self-referencing canonical URL and a completed research record enter the sitemap. No city × product × platform combinations are generated. The sitemap groups URLs by products, places, guides and terms, and uses substantive update dates rather than the build time.