BSI regularly reviews and updates British Standards (BS), but the effect of a new revision depends on the type of standard. This article focuses on two categories: standards produced by BSI for UK use (BSs), and European Norms (ENs) adopted by BSI for UK use (BS ENs).
BS and BS EN standards
For ENs, BSI must publish all ENs and withdraw any conflicting British Standards. These are published as BS ENs, or BS EN ISOs, using the EN standard number. Any conflicting existing BSs are withdrawn after a coexistence period of up to 21 months. https://www.thenbs.com/knowledge/standards-explained-part-one-british-standards
Designated Standards
Some BS ENs are ‘designated’ standards, formerly known as ‘harmonised’ standards. Products marketed in Great Britain must conform to any relevant designated standard. When a new version is published, both the new version and the existing designated version may be current. Specifiers, designers, builders and others may use the newer version, but products must still conform to the designated version. If there is a conflict, the designated version takes precedence because it remains the legal requirement until the newer revision is designated, if that happens.
A façade industry example is BS EN 13830 Curtain walling. Product standard. The 2003 version is listed on British Standards Online (BSOL) as superseded and withdrawn because a newer 2015 version exists, incorporating 2020 amendments. However, the 2003 version remains designated, so curtain walling products marketed in the UK must comply with the 2003 version. Project teams may refer to the newer version, but should recognise that the 2003 version remains the legally designated standard, which is used for conformity marking purposes.
A list of designated standards for construction products is available here: https://www.gov.uk/government/publications/designated-standards-for-construction-products.
Non-designated standards
Unless required by other legislation, such as building regulations, standards that are not designated remain guidance or good practice (and compliance with these standards is commonly considered a minimum). Their updates are simpler, but a new version still does not immediately replace the previous one. During coexistence, both versions may remain current. For example, BS EN 1991-1-4:2026 was published in March 2026, incorporating the June 2026 corrigendum, and supersedes the 2005 version. However, the 2005 version remains current for now. The European foreword states that the EN must be endorsed or published as identical text by September 2027, with conflicting national standards withdrawn by March 2028.
National Annexes
National Annexes (NAs), which are published by a national standards body and provide country-specific guidance, add further complexity because each NA is specific to a particular version of a standard and is not automatically carried forward to a newer BS EN. Until a new NA is published, using the existing NA with the newer standard is not strictly correct, although qualified professionals may judge it appropriate in some cases, particularly where the NA mainly provides national context such as local weather data. For BS EN 1991-1-4:2026, the current NA is ‘NA to BS EN 1991-1-4:2005 + A1:2010’ and is intended for use with the 2005 version, not the 2026 version. Some location-based data may still be relevant, but using it with the 2026 standard should be done cautiously, as it may fall outside both the 2026 standard and the scope of the 2005 NA.
Summary
In summary, during coexistence periods, specifiers, designers and others may choose which current version to use, but should prepare for the older version to be withdrawn and update their work accordingly. The exception is designated standards: products must conform to the designated version, even if that version has been superseded or withdrawn elsewhere.
Practical checks for project teams
- Record the full standard number, edition and amendments,
- Check whether the version is current,
- Review coexistence and withdrawal dates,
- Check whether it is designated and which edition is cited,
- Confirm that the National Annex matches the selected BS EN,
- Document the effect of revisions on design, specification and product compliance.