Change in procedure when determining Execution Class
Published on: Tuesday, 8th December 2015
Kevin Jones, Sales Director for Metsec’s Purlins Division, highlights the recent change that has been made when deriving the Execution Class of a project and what this change entails
The way that the Execution Class of a project should be derived has recently changed as it has been recognised by the European committee that it would be more appropriate for guidance to be given in the design standard, from the method in BS EN 1993-1-1. Highlighting this change will help specifiers and engineers understand their role in the steel construction supply chain.
Execution Class is a relatively new concept introduced in BS EN 1090-2, which defines four levels of quality control processes for the fabrication industry. These different levels are used for two things: determining what level of quality control a fabricator provides, and for specifiers and engineers to determine the level of quality control required for a structure. This means that at the beginning of a project, the required quality of fabrication for the structure, the components, and the finer details for each development must be specified by the engineer.
As the recommendations on how to derive the Execution Class of a structure have always been based in BS EN 1090-2, which is the fabrication standard, it has meant that specifiers and engineers have been unaware that it is their responsibility to stipulate what kind of products are used on a project.
The new way of determining Execution Class
To determine the Execution Class for a project, engineers can follow a two-step process, rather than a four-step process that was previously in place:
- Determine the Consequence Class - ensures that buildings and other structures are constructed with the appropriate level of quality control within the fabrication process (table 11 of Approved Document A is used to determine the Consequence Class).
- Select the Execution Class - having determined the Consequences Class for a building, the required Execution Class is simply derived from Table NA.4 (please see below) of the National Annex to BS EN 1993-1-1.
What does this change mean?
Although BS EN 1090-2 remains current, Annex B, which provides guidance on determining the Execution Class, is classed as informative, and has been removed in the latest draft of the standard . The annex in BS EN 1993-1-1 (Annex C) is classed as normative, making it an essential part of the standard and it’s therefore recommended that this method is used for any future projects.
Metsec is up to date with this change to the Execution Class as all of its products for use in construction are CE marked under the Construction Products Regulation. Our processes are certified up to Execution Class 4, which is the highest accreditation available, meaning we can deliver the required standards, regardless of the scale or bespoke nature of a project.