Fire doors (with diagram)

[Sd352]

We are in the process of finishing a side return extension and frankly a bit lost at the fire door requirements. I have added an illustration of the extension on the current floor plan.

The question is which, if any, of the doors need to be fire doors. I am finding the building regs on fire doors absolutely perplexing and I am a lawyer! I was hoping someone may be able to provide some guidance because our builder and architect have been rather useless.

The loft was converted before we bought the house so it does now make the house a 3 story house.

Door 1 is the new door between the kitchen and the hallway.

Door 2 is the door between the original entrance to the kitchen and the hallway but now it is just a door between the main hallway and the bit of the hallway between the utility room and downstairs so I expect this door can be removed entirely.

Door 3 is the door between the living room and the kitchen (which used to lead to the side return and is now an internal door).

Doors 4 and 5 are just the doors from the living room (knocked through at some point, so just one big room) to the hallway.

Our architect is saying doors 3, 4 and 5 need to be fire doors, which makes no sense to me. My best guess is that door 1 needs to be a fire door but not sure about any of the others.

Any thoughts, suggestions, guidance?

When we had an extension and extras the only fire door needed was from (integral) garage to house. Due to potential of car catching fire. (If only we could fit a car in our garage 😂) I don't know why you would need a fire door between normal rooms?

I thought fire doors should separate sources of fire (kitchen + living room if it has a fireplace) from the stairs and bedrooms. but i'm not an expert

I would say none need to be fire doors, I'm a building surveyor. But to be sure can't you just ask the building control officer assigned next time they come out for an inspection? If they've not mentioned it already at a visit, or with the plans approval I'd suggest none are needed.

3 storey house generally needs fire doors to protect the escape route, so doors opening onto the stairway, landing, passage, hall.

But I am not up to date on this

I have such a house and have fitted matching fire doors throughout, because I like their solidity and sound blocking, including bathrooms and WCs.

I think if you have a loft extension or a floor above first then door that you can walk through and access the stairs has to be a fire door but you're local fire officer should be able to help you.