Fire doors in dwelling with two staircases

[Guest Tom]

Wonder if someone could offer some advice please?

I've had a read through Approved Doc B1 but still remain a little confused...

We have just purchased a property which previously had an extension added (2009). The original house is composed of two storeys. The extension was built with a single habitable loft room. Currently all doors that open onto the extension stairwell are FDs to a final ground floor exit.

The main house and extension are currently only connected via an internal door on the ground floor and we intend to make an opening on the first floor to allow access throughout. This stairwell would open into a lounge which has double patio doors leading directly outside.

Therefore, with our proposal, the single set of stairs from the 'loft room' would now lead to the first floor landing area from which escape could then be via either continuing down the existing extension stairs or going along the landing (through a door and the new opening) to the main house stairs to an alternative external door in the hallway. In this instance, is a protect stairwell to ground level required with FDs as paragraph 2.4 in AD B1 would seem to suggest not?

2.4 Dwelling houses with one internal stair should comply with paragraphs 2.5 and 2.6. In dwelling houses with more than one stair, the stairs should provide effective alternative means of escape. The stairs should be physically separated by either of the following.

a. Fire resisting construction (minimum REI 30).

b. More than one room.

Many thanks.

 

 

[Tom Sutton]

If you do not install a FD30s door how do you get fire resisting construction (minimum REI 30) between the two staircases and if you go for b which are the two rooms separating the two staircases?

Verbal description is difficult to understand fully, drawings are much better.

[Guest Tom]

Hi Tom,

Many thanks for your reply.

I'm having trouble uploaded a couple of jpgs to more clearly show what I mean at the moment! As soon as I am able I will do so (it just says "loading" by the paperclip)

My apologies though, the door on the landing is indeed to be an FD30 door.

Kind regards.

[Tom f]

Hi Tom,

Many thanks for your reply.

I have uploaded a couple of images to better show what I mean.

Apologies from my first post above - yes, the door is intended to be an FD30.

[Tom Sutton]

I am assuming all the walls, partitions and doors enclosing the staircases meet the required standards.

The staircase in the extension, Ground, 1st & 2nd floors require to be a fully enclosed, protected to a half hour standard, to a final exit, which it will not be according to your proposals. If a fire broke out in the habitable room on the ground floor, people in the habitable room on the 2nd floor would be trapped.

The staircase in the existing building, ground and first floor only need to be protected to a FD20 standard (substantial well fitting standard doors would also be acceptable) providing you have emergency egress windows in all you habitable rooms.

The proposed 1st floor appear acceptable, except you  have an inner room situation which would need more consideration, an inner room requires an emergency egress window.