From 1 July 2014 the harmonised standard, BS EN 1090 Execution of steel structures and aluminium structures came in to force, making it an offence to supply fabricated structural steelwork or aluminium to site that does not conform to the standard and carry the CE mark.

Clients and contractors are only permitted to use firms that are certified to provide product that is CE marked with a specific ‘Execution Class’ appropriate for the project as defined in BS EN 1090-1.

Depending on the nature of the offence, penalties include suspension notices, prohibition notices, notices to warn, application for forfeiture, fines, or imprisonment. Failure to comply may also invalidate project insurance and warranties.

Metalwork contractors need to be certified by a notified body to be able to apply CE Marked product and to have Factory Production Control (FPC) procedures for traceability, welder and operator competence, equipment calibration, production quality control and so on.

Notified bodies approved by UKAS issue an FPC certificate and Welding Certificate to companies that meet the requirements of EN1090. To find out more about EN1090 and CE Marking contact us. Our certified weld engineer can help you to implement an FPC and weld controls to meet EN1090 or to develop your own weld standards and processes.


Who needs to comply with BS EN 1090-1?

The BS EN 1090 1 CE marking for structural steel regulations apply to a wide range of activities involving “series” manufactured items:

  • Manufacturers of metal components or kits that have a structural use in civil engineering.
  • Importers of structural metalwork kits or components
  • Stockholders and metal processors that modify stock – for example by drilling, painting, bending, electroplating etc.

Within EN 1901-1 The term “series” means mass produced or more than one for example multiple production such as staircases but not necessarily an access platform as a one off (non-series) production, however the controls required are same and many larger organisations purchasing structural/fabricated steel may insist on CE Marking to ensure they have net their legal duty of care.


What do I need to do to comply BS EN 1090 1?

There are 3 “consequence classes” in EN 1090-1 and it is anticipated that the majority of structural steel fabricators in the UK will fall within consequence class 2.

Consequence class 1 (CC 1) Low Low possibility of loss of human life, or economic impact, social or environmental consequence – minimal to negligible loss Agricultural buildings where people do not normally enter, low use, storage areas, greenhouses, etc.
Consequence class 2 (CC 2) Medium Medium possibility of loss of human life, or economic impact, social or environmental consequence – considerable loss Residential and or office buildings with regular use, although not highly populated
Consequence class 3 (CC 3) High High possibility of loss of human life, or economic impact, social or environmental consequence –very great and serious impact Stadium, concert hall, public buildings, etc. human activity very high usage most days of the year

You need to have what is known as an FPC (Factory Production Control system) this is set of procedures and documentation that ensure the following amongst other requirements:

  • Traceability of materials (to original mill certs and test results)
  • Competence of welders/fabricators (coded welders/weld testing)
  • A responsible welding coordinator needs to be appointed
  • Drawings and calculations to prove the structural integrity of materials/fabricated items
  • Calibration of equipment (welding equipment)
  • Control of defective materials and products with corrective action process (fixing errors)
  • Purchasing procedures and approval for materials and subcontractors
  • Quality control systems to ensure the quality of manufactured products

Holding certification to ISO 9001 will provide the majority of evidence required for EN 1090 1 but you will need some additional controls as detailed above. When all this is in place you need to have a third-party audit/inspection by a notified body which is UKAS accredited


Four Step Process for Execution Class Selection

The following four steps will guide you through the execution class selection process:

  1. Define the consequence class
  2. Select a service category
  3. Select a production category
  4. Use the results of steps 1, 2 and 3 and a matrix to determine your execution class.


  1. Define the consequence class

The purpose of defining a consequence class is to ensure that buildings (and other structures) are constructed with the appropriate level of quality control. Consequence classes are based on building type, building height (number of storeys), floor plan area per storey (for retail) and occupancy. A structure, or a part of it, could also contain components with different consequence classes. In most cases, CC2 will be suitable.

Class Description Examples*
CC3 High consequence Stadiums and concert halls for 5,000+ people, buildings storing hazardous substances
CC2 Medium consequence Most multi-storey residential and commercial buildings, hotels, hospitals, education establishments and car parks
CC1 Low consequence Agricultural or storage buildings

*Refer to Annex A, BS EN 1991-1-7 (Eurocode 1) for more examples of building categorisation


  1. Select a service category

Service categories reflect the risk arising from the actions to which the structure and its parts are likely to be exposed during erection and use, such as fatigue and likelihood of seismic actions. They also look at the stress levels in the components in relation to their resistance.

Service categories are determined from Table B.1 of BS EN 1090-2. In the UK, for instance, SC1 will generally be appropriate.

Category Criteria
SC1 Structures/components designed for quasi actions only, e.g. buildings
SC2 Structures/components designed for fatigue actions to EC3 such as bridges, or
located in regions with medium/high seismic activity


  1. Select a production category

Production categories are determined by the risk arising from the fabrication complexity of the structure and its components. This may entail the application of particular techniques, procedures and controls.

Production categories are determined from Table B.2 of BS EN 1090-2 and it should be noted that a structure or part of a structure may contain components or structural details that belong to different production categories. However, the execution class is not always sensitive to the production category.

Categories Criteria
PC1 Non-welded components or welded components from steel grades below S355
PC2 Welded components manufactured from steel grades from S355 and above


  1. Use the results of steps 1, 2 and 3 and a matrix to determine your execution class

Once the consequence class, service category and production category have been determined for a building, Table B.3 of BS EN 1090-2 defines the corresponding execution class. In the UK, for instance, EXC2 will be applicable to most buildings. Where no execution class is specified, Clause 4.1.2 of BS EN 1090-2 states that EXC2 applies.

Consequence class CC1 CC2 CC3
Service category SC1 SC2 SC1 SC2 SC1 SC2
Production category PC1 EXC1 EXC2 EXC2 EXC3 EXC3 EXC3

For full details refer to Annex B, BS EN 1090-2.