Fire / building regulations - building new flats above existing in roofspace

[clairerebecs]

There is a planning application in at the moment (which we are objecting to). We live in a ground floor 2 bed flat within a 1960s purpose built, 4 storey development. The owner of the building now wants to build 4 new flats in the roofspace (making a total of 5 floors). How will this affect building regs? Currently there are 24 flats with 3 stairwells. Each stairwell gives access to 8 flats in total (2 flats on each floor). We have heard that if the planning app goes through, we may need to have fire doors installed in our flats (to replace all internal doors + have a new 'front' door) as a result of these new flats going up. Does anyone know if this is correct? Can they really make us do this?

[terryb3]

If your main access to your flat is straight to the oustide it will not change
If it is off a common staircaes, then this must be a protected shaft, and have fire resistant construciion to enable all flats in all floors to escape in case iof fitre unhindered.
Regarding your internal doors, these will probably not change, as the main door must already be FR rated to protect the above mentioned.
Stairwell and corridor widths are taken into consideration regarding the flor of peolpe thru them in an emeregency, in this case there will be a 25% increase wich will have to be acceptable to the LABC
If either your main door or the internal doors do need chnaging you can get the costs paid for by the developer under "betterement"
Don't confuse planning permission and BuildingRegulation approval
The first has no regard to any of your points, the second is soley manage it.
Hope that is helpful

[buildersmate]

Great answer.