What is EN 1090 Certification, and why is it Necessary

BS EN 1090 & UKCA Compliance

Stour Engineering LLP

Stour Engineering manufactures and supplies fabricated structural steelwork in full compliance with current UK regulations and recognised industry standards.

CE Marking Update

From July 2025, CE marking is no longer valid in Great Britain.
All structural steelwork placed on the market in England, Scotland and Wales must now carry the UKCA mark.

BS EN 1090 Explained

BS EN 1090 is the harmonised standard governing the fabrication and assembly of structural steel and aluminium. It became a legal requirement in July 2014 for fabricated structural steel, as these products are considered safety critical.

Following Brexit, the UKCA mark replaced CE marking in Great Britain to demonstrate compliance with BS EN 1090.

The standard consists of:

  • BS EN 1090-1 – Conformity assessment and UKCA marking

  • BS EN 1090-2 – Technical requirements for steel structures

  • BS EN 1090-3 – Technical requirements for aluminium structures

Execution Classes

Structural steelwork falls into one of four execution classes:

  • EXC1 – Low-risk structures (e.g. agricultural buildings)

  • EXC2 – Most common class, including residential and commercial buildings

  • EXC3 – High-risk structures such as bridges and large multi-storey buildings

  • EXC4 – Highest risk, complex or critical structures

Impact on Buyers and Contractors

Responsibility: 

  • Contractors and builders have a responsibility to check that materials have the correct UKCA/CE markings to avoid potential structural risks, failed inspections, and legal issues.

  • Verification: You should verify that the steel fabricator is certified to the correct Execution Class (EXC1–EXC4) for your project. 

  • In summary, buying or using non-marked steel poses a high risk of being illegal and against building safety regulations, leaving you vulnerable to enforcement actions.

Our Commitment to Quality

Working to BS EN 1090 ensures full traceability, quality control and compliance throughout the manufacturing process, including:

  • Certified materials and consumables

  • Qualified and tested welders

  • Controlled fabrication procedures

  • Inspection, testing and documentation

All welders are qualified in accordance with BS EN ISO 9606-1, with ongoing six-monthly continuity checks.

BS EN 1090 Certified Fabrication

Our certification allows Stour Engineering to fabricate structural steelwork for residential, commercial and agricultural projects, typically up to EXC2.