What’s changing in the updated FprEN 1993 Eurocode 3 – Design of Steel Structures?

A European Design Standard, with country specific annexes and design guides

Eurocode 3 provides both general and structure specific recommendations for the design of steel structures that can be used by design engineers, fabricators and manufacturers to create safe, durable, and sustainable steel structures. It was first published between 2002 and 2007 to enable the design of building and civil engineering works, and to determine the performance of structural construction products.

It has been adopted throughout Europe as the design standard for steel structures. It provides a common set of design rules to be used with a country’s National Annex. There have been significant advances in research, product performance and state-of-the-art practices, hence the review and updates which will be rolled out in the forthcoming years.

When will the second generation be published and mandated?

They are due to be published by the end of September 2027, with a period of coexistence where the first generation of Eurocodes are current and the second generation are available, but not implementable until the date of withdrawal in March 2028.

General changes in Eurocode 3

The most general changes to the second generation of Eurocode 3 are:

• A revision of the table of contents, which means that designers will have to relearn where things are that they need to reference for design calculations
• An extension of the scope to steel grades up to S700
• EN 1993-1-12 will now include additional rules for steel grades up to S960
• Clarification on the use of verbs to indicate how rigorously a clause should be applied by designers when using the recommendations given in the standards
• There are two new parts. EN 1993-1-13 provides rules for beams with large web openings and EN 1993-1-14 outlines a common approach for the design of steel structures designed using finite element analysis

Some of the most important specific changes

EN 1993-1-1: Design of Steel Structures. Part 1-1 – General Rules and Rules for Buildings

EN 1993-1-1 deals with the structural design of individual components such as beams, columns, and the design of whole structures. It includes recommendations on the types of steel to be used and the material properties that should be used in the design.

The revised version of EN 1993-1-1 includes an extension of the scope to allow steel grades up to S700 to be used. As a result, the ductility recommendations need to be revised to reflect the reduced ductility of higher strength steels, particularly when considering the design resistance of a section with holes.

The revision also includes a new method for determining the lateral-torsional buckling of beams.

Other changes include; the design of elliptical hollow sections, the methods for structural analysis have been refined and summarised in a flowchart, a new method for the design of semi-compact sections (class 3), an improvement in the effects of torsion on the resistance of cross-sections and members, a simplified design approach for fatigue, an annex providing statistical data of material and dimensional properties that were used for the calibration of the default partial factors.

EN 1993-1-2: Design of Steel Structures. Part 1-2 – Structural Fire Design

EN 1993-1-2 deals with the design of steel structures for the accidental situation of fire exposure with reference to the load bearing function and only identifies differences from, or supplements to, normal temperature design. It is only concerned with passive forms of fire protection and also covers cold-formed members.

In revised EN 1993-1-2, nominal fires are applicable to steel grades up to and including S700. However, physically based thermal actions are only applicable to steel grades up to and including S500.

EN 1993-1-3: Design of Steel Structures. Part 1-3 –Cold Formed Sections and Sheeting

EN 1993-1-3 deals with the design of cold-formed sections and sheeting.

The list of steel grades given in EN 1993-1-3 has been expanded.

Other changes include; rules added for the design of sinusoidal sheeting, the design of trapezoidal sheeting in axial compression and the bending moment resistance of liner trays. Clarification on the design formulae for cross-sectional resistance of sections in combined axial force, bending moment, shear force and torsion and of the design provisions at serviceability limit states. Minor specifications and explanations added for the buckling design of sections in combined compression and bending. New and special provisions for the design of trapezoidal sheeting with overlaps and special provisions for fasteners made of stainless steel in relation to corrosion environment deleted.

EN 1993-1-5: Design of Steel Structures. Part 1-5 – Plated Structural Elements

EN 1993-1-5 provides design rules for stiffened or unstiffened steel plates that are subject to forces applied within the plane of the plate. It covers structural elements such as I section girders, box sections and plated components used in tanks and silos.

The scope of the standard has been extended to cover non-rectangular panels.

Another change concerns the resistance of steel plate girders subjected to patch loading, with a new calculation for the reduction factor on the design resistance, recommended in Clause 6.4(1).

EN 1993-1-8: Design of Steel Structures. Part 1-8 – Joints

EN 1993-1-8 advises on the design of steel joints. This includes bolted joints, such as end plates, fin plates, and welded joints. It also covers tubular joints.

The revised standard has been extended to include the design of nominally pinned connections, with recommendations given in Annex C.

The standard also includes a new Annex D for the design of column bases with fasteners between steel and concrete.

Want to find out more about the changes to the second generation FprEN 1993 Eurocode 3 – Design of steel Structures?

The BCSA is hosting a webinar on this subject, presented by Dr Ana Girão Coelho on 30 April from 12pm to 1pm.

The presentation will include details on the evolution of the Eurocodes, where they are now and what to expect in the second generation, and where we are at in the process ahead of the withdrawal of the current Eurocodes in March 2028.

Dr Ana Girão Coelho will be giving a brief overview and take questions and answers at the end of the presentation.

To register your attendance, scan the QR code or visit