Guides fundamental to fire safety in buildings.

For new or altered buildings and are only lines on paper you have to design a fire safety strategy and the guidance used is one of three guides.

If you prefer a prescriptive approach then use Approved Document B (fire safety) and is the one Building Control Officers appear to favour.

In complicated buildings you may consider a fire engineering approach using BS 7974 (series) Application of fire safety engineering principles to the design of buildings.

Finally you could use BS 9999:2008 Code of practice for fire safety in the design, management and use of buildings which is a hybrid, using a prescriptive approach based on fire engineering principles.

You should not use cherry picking decide which guide to use and stick with it.

Check out http://www.firesafe.org.uk/fire-safety-in-new-extended-or-altered-buildings/

For existing buildings there is a myriad of guides many produced by the Department of Communities and Local Government
(DCLG) and a many can be found and downloaded from https://www.gov.uk/workplace-fire-safety-your-responsibilities