§ Standards
Status
CURRENT
Edition
2018
Last verified
2026-09-06
BSI · STANDARD
Execution of steel structures — Technical requirements for steel structures
Overview
The central execution standard for UK and European steelwork: execution classes EXC1 to EXC4, constituent products, cutting and holing, welding, bolting, erection and geometrical tolerances.
Requirements for the execution of steel structures from constituent product selection through fabrication, welding, mechanical fastening, surface treatment, erection, inspection and documentation.
Who uses it
Fabricators, checkers and inspectors setting shop requirements, tolerances and execution class.
Details
Official source: knowledge.bsigroup.com
Requirements
Execution class · Execution
Execution class EXC1 to EXC4 is selected from consequence class, service category and production category, and then drives welding, inspection, traceability and tolerance requirements for the whole job.
EXC1–EXC4Fabrication
Source: BS EN 1090-2
Weld quality · Welding
Weld acceptance is expressed as an EN ISO 5817 quality level; level C is typical for EXC2 and level B for EXC3, with additional requirements for specific imperfections.
EXC2–EXC3WeldingVisual and NDTISO 5817 level B or C
Source: BS EN 1090-2 / BS EN ISO 5817
Constituent products · Materials
Constituent products must be supplied with the inspection document required for the execution class, normally EN 10204 type 3.1 for structural steel from EXC2 upward.
EXC2+Sections, plate, hollow sections
Source: BS EN 1090-2 / BS EN 10204
Erection tolerances · Erection
Essential erection tolerances apply to column plumb, level and position; functional tolerances may be tightened by the project specification where cladding or lifts require it.
ErectionSurvey
Source: BS EN 1090-2
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Status
Editorial reference information compiled and maintained by the StructuralSteel.ai team. It is not a design certificate and is not issued under an engineer's seal.
Last reviewed
Calculations
Any figures produced on this page are indicative estimates for early sizing and comparison only — they are not engineered design outputs.
References
Final member selection, loading, connection design, fire design, fabrication and compliance must be verified for your specific project by a suitably qualified structural engineer. Standards are revised; check the edition in force where the work is built.
Verification
StructuralSteel.ai provides technical reference information and links to authoritative sources. Project specifications, applicable legislation, current standards editions and requirements of the responsible engineer or authority should always be verified before fabrication or supply.