On Friday, 14 June 2019 19:02:38 UTC+1, Jim GM4DHJ ... wrote:
like a three storey house is more dangerous than a two storey house .......

They are, which is why Building Regs for 3-storey houses are more onerous.

For HMOs:

Statistics show that residents are six times more likely to die in a house fire if they live in an HMO. And if the HMO is three or more storeys high, the probability increases to 16 times more likely.

https://www.ifsecglobal.com/fire/hou...on-in-england/

Owain