CE marking and DoP for windows and doors: the retailer's guide

There’s a question that comes up often from those reselling windows and doors under their own name: if I put my brand on a window made by someone else, what am I responsible for under CE marking? It’s a legitimate question, and the answer isn’t as simple as it looks. Many retailers treat it as a bureaucratic formality for the manufacturer — “the factory sorts that out” — only to be caught out when a site manager asks for the Declaration of Performance (DoP) made out to whoever appears on the label, or when an acceptance check stalls over an essential characteristic that wasn’t declared.

This article covers only that: what CE marking and the DoP are for windows and doors, who counts as the “manufacturer” for regulatory purposes, and what actually changes if you sell under your own brand. It isn’t legal guidance and doesn’t replace an advisor or a notified body — in fact, on more than one point we’ll tell you explicitly to check with them. It’s a practical map of where to look before signing a supply agreement or printing your label on the products.

A note on method: where we cite regulations, we do so carefully and in the correct general terms. The exact split of responsibilities in your specific case depends on the contract and the role you take on in the market, and needs validating case by case.

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CE marking and EN 14351-1: what we’re actually certifying

External windows and doors (windows and external pedestrian doorsets) fall within the scope of the harmonised standard EN 14351-1. “Harmonised” means it’s the product standard that makes CE marking of windows and external doors placed on the market both possible and mandatory. In this context, CE marking isn’t a generic quality stamp: it’s the way the manufacturer declares — in a verifiable, traceable way — the product’s performance against the essential characteristics set out for it.

The legal framework of reference is Regulation (EU) No 305/2011, known as the CPR (Construction Products Regulation). The CPR states that, for construction products covered by a harmonised standard, whoever places the product on the market must:

1. draw up the Declaration of Performance (DoP);
2. affix CE marking to the product (or to the label / accompanying documents, according to the arrangements provided for).

In short: the DoP is the document, CE marking is the mark that points back to it. The two travel together. There’s no legitimate CE marking without a DoP behind it, and the DoP loses its meaning if it isn’t linked to an actually marked product.

An important clarification, to avoid confusion: CE marking attests that the declared performance is real and was obtained through a correct assessment system. It doesn’t mean “this is the best product”. It means “this product has these performance figures, declared by this party, and you can trust the data”. For your professional customer (contractor, designer, site manager), that data is what they need for their own compliance obligations.

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Who is the “manufacturer” for CPR purposes (the part that concerns you)

This is the crux that directly concerns anyone reselling under their own brand. The CPR thinks in terms of roles, not who physically cut the profiles. And it carefully defines who the “manufacturer” is.

In general terms — and here we’d urge you to check the exact wording and how it applies to your case with an advisor — the Regulation treats as manufacturer whoever manufactures a construction product, but extends similar considerations to whoever places a product on the market under their own name or brand. That’s the phrase that changes everything for private label.

The practical consequence, not to be underestimated:

If you take a window or door made by a third party and place it on the market under your own name, you could — for CPR purposes — take on obligations and liabilities typical of the manufacturer, not just a branding choice.

This doesn’t automatically mean you have to redo laboratory tests or run the factory production control system yourself. It means the split of responsibilities needs to be defined and put in writing, because it isn’t a given. Three typical scenarios, for guidance:

Scenario	Who appears as manufacturer on DoP/CE	What you need to check
You buy under the manufacturer’s brand	The manufacturer	That the DoP exists, is consistent, and is delivered to you
You buy and resell without altering anything, keeping the original marking and brand	The manufacturer (you’re a distributor)	Your obligations as a distributor: keeping documents, not removing the marking
You sell under your own brand (private label)	The role could shift to you	The contractual split and compliance with the manufacturer’s obligations

The last row is the critical one. This isn’t something to settle “by feel”. It needs to be clarified in the supply contract and, where necessary, validated with a notified body or a technical-legal advisor. A serious manufacturer not only has no problem discussing this, but helps you structure it correctly. We cover the branding choice itself — whether or not to put your own brand on — separately, in the article on private label vs. own brand, because that’s a commercial question; here we’re staying on certification liability.

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The essential characteristics to declare

The DoP isn’t a generic sheet: it declares the essential characteristics of the window or door, each with its class or value according to the test method set out in EN 14351-1. Which ones are “mandatory” to declare also depends on the intended use and the applicable requirements — another reason not to improvise. For guidance, the characteristics that come up most often, and that your professional customer expects to find:

Essential characteristic	What it indicates	Typical reference
Thermal transmittance (Uw)	Thermal insulation of the whole window/door unit	Value in W/m²K
Watertightness	Resistance to water infiltration	Class (e.g. from 1A to 9A / Exxx)
Air permeability	Airtightness	Class (e.g. from 1 to 4)
Resistance to wind load	Resistance to wind pressure	Class (e.g. from A1 to C5)
Acoustic performance	Sound reduction (Rw)	Value in dB, if declared
Load-bearing capacity of safety devices	For certain typologies	According to the applicable method

Three practical observations, because this is where problems arise on site:

• The values belong to the finished window/door unit, not the “profile”. The Uw transmittance depends on the profile system and the glass and the spacer and the size. The same Salamander frame gives a different Uw with double glazing versus triple glazing. The DoP refers to the configuration actually produced, not a catalogue value for the profile alone.
• A characteristic that isn’t applicable is declared as such. If a characteristic doesn’t apply to that use, there’s a correct way to indicate that. It isn’t simply left blank at random.
• Consistency between the declared data and the actual configuration is what holds up under an acceptance check. If the DoP says one thing and the label or the order says another, that’s exactly where the site manager stops the job.

Starting from a certified profile system simplifies this part considerably: Salamander systems come with test records and system documentation to build the finished window/door declarations on. It doesn’t remove your obligations, but it gives you a solid, traceable basis to start from. On why a certified profile system makes a real difference in practice, we’ve dedicated a piece to Salamander profiles designed for window and door fitters.

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The documentation to keep

Regardless of the role you take on, there are documents it’s reasonable to have and keep in order. The detail of the formal obligations and retention periods needs checking — the CPR has specific provisions here too — but the practical logic is this:

• The DoP for each product/configuration, in the version delivered to the customer. If you sell 14 windows in three different configurations, the configurations have DoPs consistent with what you actually supplied.
• The label / CE marking as applied, with the details of whoever appears as manufacturer and the reference to the DoP.
• The supporting technical documentation justifying the declared performance (system test reports, calculations, data from the profile and glass supplier). This part typically stays with whoever manages the assessment, but it must be retrievable.
• The supply contract clarifying who does what for CPR purposes. It sounds like an administrative detail; it’s actually the document that protects you if someone challenges the marking tomorrow.

A general CPR principle worth keeping in mind: whoever distributes a construction product must not remove or alter the CE marking, and must make sure the product is accompanied by the required documents. If you relabel, modify or assemble, that changes things — and that’s exactly the private label case, to be handled carefully.

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Mistakes that stall an acceptance check

Let’s look at the concrete cases that stop a supply or an acceptance check. They’re almost always problems of documentary consistency, not product quality.

• Missing or undelivered DoP. The product is excellent, but the site manager can’t sign off without the document. This happens more often than you’d think when the supply chain has too many links.
• DoP made out to the wrong party. The label carries your brand, but the DoP points to a different name with no clarification of the relationship. This raises doubts and requests for further documentation.
• Declared values inconsistent with the configuration supplied. A catalogue Uw for the profile instead of the finished window/door, a watertightness class that doesn’t match the actual product. This is the most technically insidious error.
• An essential characteristic required by the specification but not declared. If the specification requires a minimum acoustic performance and the DoP doesn’t state it, the data needed for verification is missing.
• CE marking absent or illegible on the product or on the accompanying documents.

The practical rule we always give: certification gets checked before the order, not at the acceptance check. Ask the manufacturer for a sample DoP and label on the configuration you’ll be selling, and verify that the data matches what you’re going to tell your customer. This links well with the choice of supplier — we cover it too in the guide on how to choose a reliable window and door supplier, where documentary solidity is one of the criteria.

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When it’s NOT worth it

Putting your own brand on the product and (potentially) taking on the role of manufacturer for CPR purposes isn’t always the right move. Some cases worth pausing to consider:

• You don’t have the structure to manage the documentation. If you don’t have someone keeping DoPs, labels and contracts in order, private label exposes you more than it gives you. Better to resell under the manufacturer’s brand, staying in the distributor role with more limited obligations.
• You sell occasional, varied volumes. If every order is a different, non-recurring configuration, managing documentation under your own brand becomes onerous relative to the benefit. The own-brand model pays off on stable ranges and volumes.
• You haven’t yet clarified the split of responsibilities with the manufacturer. Until the contract clearly states who is the manufacturer for CPR purposes and who keeps what, putting your own brand on is premature. Contract first, label second.
• Your customer places no value on your brand on the product. If you sell to purely price-driven customers, the certification burden of private label isn’t offset by a commercial return. The economics of this assessment are covered in the article on margins and private label for the retailer.

In all these cases, the manufacturer’s CE marking and DoP remain valid and usable: you simply don’t take on the manufacturer’s role. It’s a legitimate choice, and often the more sensible one at an early stage.

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FAQ

Q: If I sell under my own brand, do I have to redo the laboratory tests?

Not necessarily. Tests are typically tied to the profile system and configuration, and may already be available from the manufacturer or the system supplier. The point isn’t “redoing the tests”, but defining who takes on the manufacturer role for CPR purposes and on what documentary basis the DoP under your brand rests. This is exactly the kind of thing to clarify in the supply contract and, if in doubt, to check with a notified body or an advisor. Don’t improvise on this point.

Q: Is CE marking a quality certification?

No, and this is a common misunderstanding. CE marking attests that the declared performance is real and was obtained through a correct assessment method. It says “this product has this performance”, not “this product is the best”. For your professional customer it’s still the data they need for their own compliance, but it shouldn’t be presented as a quality award.

Q: Who actually draws up the DoP, me or the manufacturer?

It depends on the role you take on. If you resell under the manufacturer’s brand, they draw it up and you keep and deliver it. If you sell under your own brand and the manufacturer’s role shifts (wholly or partly) to you, responsibility for the declaration shifts accordingly. The key point: it needs to be defined contractually beforehand, not discovered at the acceptance check. Check the precise wording with an advisor.

Q: Which characteristics must I declare in the DoP?

The essential characteristics relevant under EN 14351-1 — typically thermal transmittance (Uw), watertightness, air permeability, resistance to wind load, and, where relevant, acoustic performance. Which ones must be declared, and how, also depends on the intended use and applicable requirements. It’s a point to verify on the specific configuration, not to copy from memory.

Q: Can I use the profile catalogue’s Uw values in my DoP?

Careful: the value declared is that of the finished window/door unit, not the profile alone. The same frame gives different transmittance figures with different glass. Using a profile catalogue value as if it were the finished unit’s is one of the errors that generates inconsistencies and stalls acceptance checks. The data must be referred to the configuration actually produced.

Q: How do I keep documents separate if I sell different configurations?

The logic is: every configuration needs a DoP consistent with what you actually supplied, and the label on the product must point back to that DoP. If you sell three configurations in one order, you need declarations consistent with each. Keeping this in order is half the work of getting through an acceptance check without requests for further documentation.

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In summary

CE marking (EN 14351-1) and the DoP (CPR Regulation 305/2011) aren’t a factory-floor detail: for those selling under their own brand, they can shift the manufacturer’s role — and with it, obligations and liabilities — onto their own name. The practical point isn’t to fear the regulation, but to clarify it: who is the manufacturer for CPR purposes, which essential characteristics are declared, which documents are kept, and how to ensure consistency between the declared data and the real product.

Three things to take away: one, check the DoP and label before the order, not at the acceptance check; two, start from a certified profile system to have a solid documentary basis; three, define the split of responsibilities in the contract and, on doubtful points, check with a notified body or an advisor — this guide doesn’t replace that step.

If you’re weighing up an own-brand supply and want to understand how we manage certification and documentation in a private-label relationship, the starting point is the page dedicated to private-label / third-party manufacturing.