BS 476 Removal 2029: Fire Resistance Compliance Guide

Both systems are similar in their structure for classification with product-specific test methods, exposing specimens to the standard time-temperature curve using furnaces to assess integrity, insulation, sustained flaming, and temperature rise.

BS 476 originates from the Royal Institute of British Architect’s request in 1929 for the standardisation of fire resistance and incombustibility testing, resulting in the publication of BS 476 in 1932.

The European fire resistance classification, BS EN 13501-2, was last updated in 2023 and has remained in place in the UK, despite the nation no longer being in the European Union, as the UK continues to play a leading role in European fire resistance standards.

When BS 476 is removed from fire resistance standards in 2029, BS EN 13501-2 will be the sole classification system for fire resistance compliance in the UK. The European standard is stronger, clearer, and more transparent, with attributes that are fundamental when dealing with fire safety.

The difference of classifications

The two classifications are largely similar, but with a few key differences to be aware of when the regulations change to solely comply with BS EN 13501-2.

For BS EN 13501-2, the furnace temperature measurement method consists of a thermocouple mounted behind an insulating pad and steel plate, slowing the response. This different measurement technique to BS 476’s bare-wire thermocouple typically results in the approach being 15–20% more onerous.
Under BS EN 13501-2, only EN test methods are valid. When a product’s fire resistance differs to the measurements recorded in testing, the extension of scope is established through an Extended Field of Application (EXAP), which is governed by standardised rules to be more transparent and consistent across the industry.

The main element to be aware of within manufacturing is that there is typically a 5-20% reduction in fire resistance performance when testing to BS EN 13501, so products require additional engineering to achieve a similar level of resistance measured under BS 476 testing.

The two classifications are largely similar, but with a few key differences to be aware of when the regulations change to solely comply with BS EN 13501-2.

For BS EN 13501-2, the furnace temperature measurement method consists of a thermocouple mounted behind an insulating pad and steel plate, slowing the response. This different measurement technique to BS 476’s bare-wire thermocouple typically results in the approach being 15–20% more onerous.
Under BS EN 13501-2, only EN test methods are valid. When a product’s fire resistance differs to the measurements recorded in testing, the extension of scope is established through an Extended Field of Application (EXAP), which is governed by standardised rules to be more transparent and consistent across the industry.

As manufacturers transition to BS EN 13501 testing, there are opportunities to extend products further without needing to test every configuration of them. Under the European standards, manufacturers can extend the application of their product using an EXAP report – this involves using an agreed set of rules and all the available fire resistance test evidence to allow for changes to elements of the product such as height and width.

“The changes in fire resistance standards emphasises the desire for clearer and stronger guidelines.
“At UKTC, we have heavily invested to ensure our clients and the wider industry can confidently navigate this shift in compliance – our laboratories already operate with fire testing equipment designed to meet BS EN 13501 and to accommodate for further developments. We’re leading this transition in the next chapter of fire resistance testing.”

Dan Fitzsimmons, Head of Testing at UKTC, A SOCOTEC Company