Approved Document Part B Update : Section 10 ‘Resisting Fire Spread Over External Walls’.

Further to the December 2022 update to approved Document Part B, we are providing an update on the relevant guidance for our standard plastic ventilation products and non-combustible ventilation products. Following the amendment to approved document Part B in England, all ‘Residential’ purpose groups have now been included within section 10 ‘Resisting Fire Spread Over External Walls’.

Approved Document B Volume 1: Dwellings (

The latest amendments restrict the use of combustible materials in external wall surfaces on all residential building’s over 11m high, or on any section of a residential building below 11m which is less than 1m from the relevant boundary.

The latest guidance will require non-combustible ventilation products, rather than our standard plastic ventilation products.

Building Type examples:

*Residential – House Building & Other Residential, Institutional or Hospitality (Wherever any persons will sleep overnight).

**Assembly, Recreation & any other building – eg. places of entertainment, work etc. (where people may congregate but do not sleep overnight).



For more guidance on this topic please contact our Specification Team

08448 50 40 50

This information relates to projects in England and Wales

For more information on Scottish projects call our Glasgow team on 0141 465 19 00or click here –

For more information on Northern Irish projects call our Belfast team on 02890 81 55 66 or click here –