Why is there a shift from BS to EN fire testing standards?
The exchange in regulatory requirements explained.
Why the Shift?
The shift from British Standards (BS) to European (EN) fire‑testing standards is driven by modernised test methodologies, stronger evidence requirements, and closer regulatory alignment. EN standards provide clearer, more robust performance data and a consistently applied classification framework, supporting the principles of the Golden Thread of fire‑safety information.
Siniat’s EN‑based testing, DIAP and EXAP validation, and EN 13501‑2 classification ensure systems meet or exceed current industry expectations, reducing ambiguity and improving confidence for designers, contractors, building control bodies, and duty holders.
EN standards incorporate clearly defined test methodologies, consistent conditions across laboratories, and enhanced reporting structures. The inclusion of DIAP and EXAP documents provides transparent rules governing permissible variations from tested configurations. This ensures EN fire‑test evidence is comparable, traceable, and easier to apply in practice. Legacy BS 476 testing does not provide equivalent classification or guidance on variation.
ADB References and Regulatory Change
Approved Document B (ADB) has historically referenced BS 476, primarily through footnotes and transitional guidance. BS 476 test results can be applied differently depending on context and do not incorporate the structured classification framework or extended application rules available within EN standards.
In recent years, regulatory direction has moved firmly towards EN‑based fire testing and classification, with Approved Document B placing greater emphasis on EN 13501 classifications for both Reaction to Fire (RtF) and Fire Resistance (FR). This reflects the clearer methodology, improved repeatability, and consistently applied classification and extended application framework provided by EN standards.
The UK Government has set out a transition away from National Class BS fire testing in favour of EN classifications, with different implementation timelines applying to RtF and FR. EN classifications for Reaction to Fire are now the primary reference point, with provisions for Fire Resistance transitioning over an extended period, currently expected to conclude later this decade.
As a result, Siniat now undertakes fire testing exclusively to EN standards and continues to invest in EN‑tested and EN‑classified systems, providing greater clarity for specification, regulatory compliance, and long‑term alignment with current and future modernisation requirements.
Siniat Position
All Siniat fire testing for partitions, ceilings, linings, shaftwall systems, and timber floor systems is carried out to EN standards, with classifications produced in accordance with EN 13501‑2.
Systems are validated using:
- Direct EN test evidence (EN 1364 and EN 1365 series)
- DIAP rules within individual test standards (e.g. EN 1364‑1, EN 1364‑2, EN 1365‑2)
- EXAP standards where available (e.g. EN 15254‑3 for partitions)
As BS 476 references continue to be withdrawn from Approved Document B over the coming years, Siniat’s EN‑only testing strategy ensures that:
- Fire‑resistant systems reflect current best practice
- Evidence aligns with evolving regulatory expectations
- Designers and building control bodies receive consistent, verifiable classification data
- Long‑term compliance is maintained as legacy national standards are phased out
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