3 storey house - are fire doors required downstairs?

[Guest Jessica Melia]

Hi, 

just after some advice as the regulations I feel aren’t very clear. We have a 3 storey house built in 2004, all doors bar the interconnecting door from kitchen to living room and bathroom doors are fire doors with self closing chain. I know the self closing chain is no longer a requirement but do we need fire doors on the downstairs doors? It says habitable rooms off the stairwell but doesn’t mention anything about downstairs rooms
 

The stairs end next to the front door so has an exit route. Do the downstairs doors to the living room and to the kitchen (not the interconnecting door) require fire doors or not? 
 

Thanks 

Jess 

[Guest martin nash]

If you do not have fire doors on the ground floor then how will you prevent the smoke from a fire in the kitchen or living room compromise the stairs and upper floors?

[Neil Ashdown MAFDI]

Are the ground floor doors there to protect the escape route in a fire?  If the answer is yes, then they should be fire doors.