Minimum door width on an escape route.

[Sydster]

Hi there,

Can anybody help please?

I have recently visited an office that had two means of escape from it leading to a protected corridor.

The door opening width from the corridor to the protected escape staircase was only 650mm wide.  The CLG guides recommendation is the minimum width is 750mm.

There is an L1 system fitted and the travel distances to this door are well within the limits.

The cost to widen the door would be prohibitive so my question is would either of these alternatives be suitable?


1. Due to the L1 system fitted, the adequate travel distances and two fire wardens available to assist in the evacuation it could be deemed acceptable.

2. Limit the amount of people in the room to 60, as it would be for a single escape route and could you support this possibility by  reversing the rule allowing an extra 15 persons for each extra 75mm. i.e 100mm less = 18 persons less.

Thanking you in advance,

Syd.

[nearlythere]

Hi there,

Can anybody help please?

I have recently visited an office that had two means of escape from it leading to a protected corridor.

The door opening width from the corridor to the protected escape staircase was only 650mm wide.  The CLG guides recommendation is the minimum width is 750mm.

There is an L1 system fitted and the travel distances to this door are well within the limits.

The cost to widen the door would be prohibitive so my question is would either of these alternatives be suitable?


1. Due to the L1 system fitted, the adequate travel distances and two fire wardens available to assist in the evacuation it could be deemed acceptable.

2. Limit the amount of people in the room to 60, as it would be for a single escape route and could you support this possibility by  reversing the rule allowing an extra 15 persons for each extra 75mm. i.e 100mm less = 18 persons less.

Thanking you in advance,

Syd.

Syd
How many would be expected to use the door in an emergency?
Is it a single stairway situation?
Is the corridor a dead end?
Is it protected?

[CivvyFSO]

There is little point in reducing the occupancy. Post war building studies looked at a single exit width being approx 525mm, so long as people can walk out single file comfortably (not having to turn sideways or anything) there would be very little difference (if any) between the evacuation times through a 650 door and a 750 door. IIRC correctly the old blue & primrose guides etc allowed 550mm widths in certain circumstances. (Small numbers of employees or something like that) I would say that 650, while not to the CLG guidance, is still an acceptable width in an office scenario, but get it in the risk assessment that, while not to current guidance, the risk is accepted and accounted for.

[Sydster]

Hi Nearly there,

Thank you for your prompt reply.

In response to your questions,

How many would be expected to use the door in an emergency? 60 although it's a multi occ and I do not know the level of occupancy for the rest of the floor. I think also that the client could potentially increase that number to 100.

Is it a single stairway situation? No, there is an alternative staircase at the other side of the building.

Is the corridor a dead end? No, At the end of the corridor is the said door to the protected staircase at the other end approx 8m away is a FRSC door which is the route to the alternative staircase.

Is it protected? Yes.

Hope this helps,

Syd.

[Sydster]

Thank you both for your assistance with this matter.  It is the first time I have posted and was extremely pleased to get an immediate and informative response,

Thank you once again,

Syd.

[CivvyFSO]

You are welcome, and welcome to the forum.