Removal of National Classes from Fire Safety Building Regulations

AMENDMENTS to Approved Document B on Fire Safety of the Building Regulations removing National Classes (BS 476) were announced today.

Currently, Approved Document B operates a dual system under European and UK standards, for reaction to fire and roofs, and for fire resistance testing and classification for construction products.

The fire safety regulations accept both the National Classes (BS 476) and the European Standard (BS EN 13501 series). Some construction manufacturers still rely on National Class test results in certificates for their products.

The European Standard is viewed as “more current and robust than the National Classes” by government. It will be the sole route of specification within Approved Document B.

Two Stage Removal

Changes to the guidance will be in two stages.

References in the regulations to BS 476 for measuring reaction to fire and roofs will be removed in a 2025 amendment and apply to new building work from 2 March 2025.

The removal of BS 476 for measuring fire resistance will no longer be accepted from 2 September 2029.

Fire Safety

The Ministry of Housing, Communities and Local Government announcement  on fire safety regulations comes just two days before publication of the final report on the Grenfell Inquiry.

The report is expected to refer to Inquiry evidence about how combustible materials responsible for the rapid spread of fire at Grenfell Tower in 2017 contributed to causing the deaths of 72 residents.

The Grenfell Inquiry was told how the British Board of Agrément (BBA) certified combustible cladding and insulation materials, suggesting equivalences with National Class 0 as suitable for use on high-rise buildings. It failed to question false European testing data provided by Arconic, Kingspan and Celotex.

The use of the two fire testing standards was seen as confusing, creating a situation where the companies could obfuscate their material’s BBA certificates.

Removal of National Classes

However, the transitional arrangements mean buildings that have lodged plans, started construction, or will start work within six months of the two deadlines can still be built.

For these buildings, the 2019 edition of Approved Document B (with the 2020 and 2022 amendments) will continue to apply.

The 2025 amendment to Approved Document B will also include implementation of the Building Safety Act.

When the new 2029 edition of the fire safety regulations comes into force, it will include two other new rules. These introduce sprinklers in care homes from 2025 and two staircases in 18m+ buildings in 2026.

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