What are the regulations on final exits?
The Building Regulations, Part B – Fire Safety, Volume 2
Any final exit door in a dwelling house or a door giving direct access to a balcony should be provided with simple fastenings (thumb latches or other openable mechanisms) that can be operated from the escape side without using a key)
‘Any’ refers to the door on the primary escape route – usually the front door (i.e. the door of the hallway serving the dwelling). In such scenarios, the patio or back door may still be locked by key and does not have to be readily openable.
The only scenario where more than one door may need to be readily openable is where the stairs delivers the occupant between two areas (either of which could be on fire) and in such cases the ‘final exit’ may be either of the doors, in which case both ‘final exits’ should be readily openable.
‘Door to balcony’ is where the door is being used as an alternative escape instead of a window.