A Declaration of Performance is the document in which a manufacturer states, under its own legal responsibility, how its product performs against the characteristics that a harmonised European standard defines for that product type. It is what gives CE marking its meaning: without a Declaration of Performance behind it, the marking on a structural component is decoration.
It is also the document that clients skim and file. That is a mistake, because it is the only place where a supplier’s claims become legally binding, and because the most important thing on it is usually what is missing rather than what is stated.
What has to be on it
The Construction Products Regulation sets both the content and the template. A compliant document carries a unique identification code for the product type, the intended use or uses, the manufacturer’s name and contact address, the system of assessment and verification of constancy of performance that applies, and the reference number and date of the harmonised standard used for the assessment. Where the applicable system requires a notified body, the declaration names that body and the certificate it issued.
Then comes the substance: the declared performance of each essential characteristic relevant to the intended use, followed by a signature on behalf of the manufacturer.
| Entry | What to check |
|---|---|
| Product type code | Matches what was ordered |
| Intended use | Covers your application |
| Standard reference | Correct part and edition |
| Notified body | Number and certificate quoted |
| Performance table | Values, not blanks |
NPD: the three letters that decide whether the document is useful
Against any characteristic for which no performance has been determined, the declaration carries the letters NPD. This is entirely legal. A manufacturer is obliged to declare at least one characteristic relevant to the declared use, not all of them, and everything else may be left undetermined.
The consequence for a buyer is direct. A declaration can be fully compliant, correctly issued, properly signed, and still tell you almost nothing about the structure you are buying, because the characteristics you care about are the ones marked NPD. Load-bearing capacity and fatigue performance are the usual candidates, and they are the two that matter most on a crossing used by the public.
Reading the document therefore starts at the NPD entries rather than at the declared ones. If the characteristic that governs your application is undetermined, the supplier has not made a claim about it, and no amount of certification elsewhere in the file changes that.
For a structural component there is more than one way to declare
Structural steel and aluminium components are covered by EN 1090-1, and it allows more than one route to the declaration depending on who carried out the design. At one end the manufacturer declares only the geometrical data and the material properties of the component, which is the correct route when the component is made to a specification the client supplied. At the other the manufacturer declares the load-bearing capacity of the component itself, which is the correct route when the manufacturer did the structural design.
The two documents look similar and mean very different things. A declaration of geometry and material properties says the component is what the drawing asked for. A declaration of structural characteristics says the component will carry the stated loads. Only the second transfers design responsibility to the manufacturer, and a client who assumed the first was the second finds out at the point where something has to be signed off.
This is why the declaration route belongs in the tender document alongside the execution class you expect the fabricator to work to. Both describe the same component, and leaving either open shifts the decision to whoever is cheapest to satisfy.
The declaration is not the certificate
Two documents travel with a certified structural component and they come from different places. The factory production control certificate is issued by a notified body after it has assessed the manufacturer’s quality system, and it says the factory is capable of making the product type it names. The Declaration of Performance is issued by the manufacturer itself and says what this product actually does.
One is third-party, narrow and about the factory. The other is self-declared, specific and about the product. A supplier that produces only the first when asked for the second has answered a different question, and the same reasoning applies when reading the scope printed on the certificate, which limits what that factory may declare in the first place.
Reading one in five minutes
Start with the product type code and confirm it is the component you ordered rather than a family it belongs to. Check that the intended use covers your application, since a declaration written for one use does not extend to another. Confirm the standard reference is the right part and a current edition, because the part of EN 1090 that applies depends on the material and a document quoting the steel part for an aluminium structure is wrong on its face.
Then read the performance table twice: once for the characteristics that are declared, and once for the ones that are not. Finish at the signature, which should name a person and a position rather than a department, since the regulation makes that person’s employer liable for what the document says.
What to require in the tender
Ask for the declaration as a deliverable at handover and ask for a specimen at tender stage. The specimen costs the supplier nothing, and it shows before award which characteristics that supplier is prepared to declare and which it habitually marks as undetermined. That single request tells you more about a fabricator than a folder of reference photographs.
It is also worth naming the characteristics you expect to see declared rather than leaving the choice open. If load-bearing capacity has to be declared for your project, say so in the technical requirements, because a supplier is entitled to leave it undetermined unless the contract says otherwise.
Before the file is accepted
The declaration is short, formulaic and easy to wave through, and it is the only document in the handover file where the manufacturer is personally on the hook for a number. Read the undetermined entries first, confirm the declaration route matches who did the design, and keep it separate in your mind from the certificate that sits beside it.
The documentation package for every structure we deliver is assembled so that these questions can be answered from the file rather than by correspondence, and the certification held by DR VERSLAS is published with its scope so the limits of what we may declare are visible before anyone signs.