EN 1090 EXC2 vs EXC3 explained: which execution class your aluminium structure needs.
What EN 1090 demands, why EXC2 is the floor for welded aluminium pergolas and fences, and the four scenarios where a specifier should escalate to EXC3.
EN 1090 is the European standard that lets a fabricator put the CE mark on a load-bearing aluminium (or steel) structural component. EXC1 through EXC4 — the four "execution classes" — set the rigour of fabrication, welding, non-destructive testing and traceability. This guide covers what determines the class, why EXC2 covers most pergolas and fences, and the scenarios where an architect should escalate to EXC3.
What EN 1090 actually demands
EN 1090-1 is the harmonised European Standard for CE marking of structural metal components placed on the EU market. The companion parts:
- EN 1090-2 — technical requirements for steel components. - EN 1090-3 — technical requirements for aluminium components.
A fabricator without an EN 1090 factory production control (FPC) certification is not legally allowed to sell load-bearing aluminium structures into the EU. The PONARC group fabrication is certified under EN 1090-3 EXC2; the Declaration of Performance (DoP) is shipped with every project.
How the execution class is chosen
EN 1090-2 / 1090-3 Annex A.3 derives the execution class from three inputs.
1. Consequence class (CC1 / CC2 / CC3) per EN 1990 Annex B — what happens if the structure fails. A garden pergola is CC1 (low — property only). A public-terrace canopy at a restaurant is CC2 (medium — multiple people exposed). A bridge or stadium roof is CC3 (high consequence — many lives at risk). 2. Service category (SC1 vs SC2) — quasi-static vs fatigue-loaded. Fixed pergolas and fences are SC1. A canopy or fence near a railway with frequent cyclic load is SC2. 3. Production category (PC1 vs PC2) — non-welded vs welded with structural welds. Almost all aluminium pergolas and fence frames are PC2.
Combine: EXC2 is the floor for any welded structural aluminium component (PC2 → EXC2 minimum per Annex A). EXC3 is mandated when CC2 + SC2 + PC2 lines up, or when the national annex / project brief explicitly demands it.
Concrete EXC2 vs EXC3 deltas
For the manufacturer:
- Welder qualification: EXC2 needs ISO 9606-2 certification per welder. EXC3 adds a project-specific Welding Procedure Specification (WPS) review per ISO 15614-2. - NDT coverage: EXC2 = 5–10 % of structural T-joints, visual + minor radiography. EXC3 = 10–20 % with mandatory radiographic or ultrasonic testing on critical fillet welds. - Welding coordinator: EXC2 = competent person. EXC3 = certified IWE / IWT (International Welding Engineer / Technologist) per ISO 14731. - Traceability: EXC2 batch-level. EXC3 piece-level with a per-assembly weld map. - Documentation pack: EXC3 adds the Welder Approval Test Records and the per-assembly Inspection Report.
For the customer / specifier:
- Lead time: EXC3 fabrication adds 2–4 weeks to a typical project. - Cost premium: Roughly 15–30 % on the structural metal cost (not the finished product cost). - Documentation: EXC3 ships with a per-assembly inspection report — useful for permit-level files.
When does an architect escalate to EXC3?
For a residential pergola or garden fence, EXC2 is the correct call. Consequence class is CC1; failure exposes property only. EXC3 makes sense in four scenarios:
1. Public assembly area — terrace canopy at a hotel, restaurant or event venue. Fall of structure could injure many people, so consequence class jumps to CC2. 2. Cyclic-load environment — fence or canopy at a transport hub (railway side, motorway shoulder), where vehicle-induced vibration is a known fatigue source pushing service category to SC2. 3. Specifier brief mandates it — large EU public-procurement projects (Bauen für die Öffentlichkeit / public-procurement code) sometimes write EXC3 into the tender as a precaution principle, even for non-structural retrofit. 4. Heritage or extreme exposure — listed-building façades, or coastal / Alpine sites with combined wind + chloride + cyclic thermal load.
If the project doesn't hit at least one of these, EXC3 is structural over-spec — adds cost and lead time without a measurable safety benefit.
What to write in the tender
Three lines for the architect's brief:
1. Execution class: "All structural aluminium components shall be CE-marked per EN 1090-3, execution class EXC2 [or EXC3 with stated reason]." 2. Welder qualification: "Welder approval per ISO 9606-2 [add: WPS review per ISO 15614-2 if EXC3]." 3. Documentation deliverable: "Manufacturer ships the EN 1090-3 Declaration of Performance plus the FPC factory certificate ID with each delivery."
Optional fall-back clause for projects on the EXC2 / EXC3 boundary: "Where the structural calculation submitted to the building authority requires escalation to EXC3, the supplier will upgrade fabrication to that class at no additional cost."
Linking back to our products + tools
The full PONARC group is EN 1090-3 EXC2 certified — Luxa Sereno motorised pergolas, the Aperio retractable louvre roof and the VisioMod fence + railing range. EXC3 substantiation is available on a per-project basis for hospitality + transport contracts.
Site-specific qb / sk values (the EN 1991 inputs that drive the CC determination) can be pulled from our wind & snow specifier calculator. The full set of structural references — EN 1991 wind/snow, EN 1090 CE marking, alloy specs, surface treatment grades — lives in the standards & norms hub.
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*Need an EN 1090-3 Declaration of Performance plus FPC certificate ID for your tender? Contact our engineering team and we'll ship the documentation pack within two working days.*
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