From our conversation with the fire brigade they state:
The Regulatory Reform (Fire Safety) Order 2005 Came in to force in October 2006. It repealed the Fire Precautions Act 1971 and Revoked the (Workplace) Regulations 1997. The RRFSO 2005 applies to all premises except single private dwellings and certain specific sites. Any premises that has paying guests however small will be regulated under this law.
We really need to get the message out to all Airbnb's that none of them are exempt from fire regulations and can be fined huge amounts for non compliance. The fire service are not taking ignorance of the law as an excuse and since Grenfell they have been particularly harsh with fines. So we need to spread the word to help owners ensure they are safe and compliant