Guide
BS 9991 vs BS 9999
The difference between the two UK fire safety codes of practice. By the Guidex team. Last updated 3 November 2026.
In this guide
What is the difference?
BS 9991 is the code of practice for fire safety in residential buildings. BS 9999 is the code of practice for fire safety in the design, management and use of other buildings.
Which one you use depends mainly on what the building is used for. Check the scope clause of the current edition for your project.
Side by side
| Point | BS 9991 | BS 9999 |
|---|---|---|
| Mainly for | Residential buildings | Other buildings, such as offices and shops |
| Latest edition seen | 2024, with a corrigendum in June 2025. It replaced the 2015 edition. | 2017. A further revision was at proposal stage in 2026. |
| Notable feature | The 2024 edition has major guidance on evacuation lifts. | It allows compensatory measures to offset items such as travel distances or door widths. |
| Covers | Design, management and use | Design, management and use |
How they relate to Approved Document B
Approved Document B is the statutory guidance. A British Standard code of practice is another way to show how a design meets the requirements. The route you use must still meet the Building Regulations.
Agree your route early with your building control body.
If your project started under BS 9991:2015
Check which edition applies to your project, and confirm it with your building control body. Guidance on this can change, so use the current published sources.
Working with both in Guidex
You can select the guidance for each project in Guidex, including the British Standards you work to and Approved Document B. Answers cite the exact clause, table or figure. Read about fire engineering AI.
This page is a general summary from published sources, and not the text of the standards. It is not advice on a specific building.
See it on your own project
The quickest way to judge Guidex is to point it at a building you already know and check its answers against your own.