External fire escape from a multi-storeyed house.

[Tom Sutton]

I received the following enquiry and I cannot find anything for the width of stairs in domestic premises which I would apply to internal or external. I found a reference to stairs in ADK1 but the width seems to apply to the approached to a domestic premises? Help would be appreciated.

I am trying to find the required dimensions for an external fire escape from a multi-storeyed house. Can you please advise? Building Regulations appear to deal with internal stairs and exits from a building.

[wee brian]

If its "part of the building" then use AD K.

[Revol]

Also worth looking in BS 5395 - 1, quoted in AD-K ... min width of a private stair should not be less than 800 mm

[col10]

It was took out of regs back in 85 under deregulation.
5395 gives good practice guidance but something narrower than 800 might be able to be justified.

[wee brian]

Sorry, didnt spot the width question.

AD K says 900mm for a stair in a dwelling (para 1.16).

I'd use that.

[Tom Sutton]

Thanks guys BS 5395 was something I missed.

[col10]

Wee b  the 900 dim in ADK was put in the 2013 edition for when you have to have a change in level in the entrance storey.  The 900 dim is not for stairway safety it is for access for disabled.
They put some of  the guidance from Doc M Access into Doc k, in an attempt to make guidance better, but it has made it worse.

[wee brian]

Sorry, I'm out of kilter with the New AD K (I agree it didn't quite simplify things as much as intended). My recolection was that there was no minimum width for a stair in a dwelling. the assumption being thatr you would be daft to make one so narrow thatr peoiple cant walk down it.

I suspect thats about 650mm give or take