Lifts opening directly onto floors - did someone remove the lobbies?

[AnthonyB]

Scenario:

Large L-shaped building over G-4th floor c1974.

Recently fully refurbished for multi letting (was owned & used by one company, who sold it and leased back some of the space)

Main stair has 2 passenger lifts in it & a part atrium (open from ground reception area to 1st level) and new FD30s doors into floorspace.

For travel distance and occupancy levels at each end of the wings there is a fire stair to final exit with original Fd30 doors and rebates - but right next to these are the openings of another lift shaft onto the open floorspace, no protection.

This doesn't look quite right & I suspect that the lifts may have originally been in a lobby off the fire stairs, backed up by one refurbished floor still having a lobby.

So you have large open floors with two different unprotected shafts into them right next to the fire stairs.

I tried to dig out the old fire cert to look for lobbies but it wasn't on site.

There is little compensation and the fire alarm people have lowered the cover with their new install - previously all the motor rooms and basement plant and switchgear plus several of the floors had DS or DH - now there is only detection to the boiler, none of the switch-rooms, the old motor room & floor DS is either gone or left in unconnected and the only other AFD is a smoke head within 1.5m of most (but not all) lift openings plus a half finished head to one fire stair landing

As a multi-occupancy with different parts occupied at different times (so manual alarm not reliable) I'm looking at restoring lobbies and/or increasing detection

What I'm wondering is if the refurb didn't go through the BCO and that lobbies have been removed??

[kurnal]

Does the floor area does exceed 2000sqm on any storey? or different occupiers as you imply?

Any requirement for compartmentation  would require the lift shafts to be protected shafts  as per ADB . The lift  may have half hour fire doors without smoke control as per table B1 and therefore compliant (but not very clever)?

[AnthonyB]

Definitely different occupiers, which is my main concern - ADB & the RRO guide both require protection, but the doors look like standard metal passenger lift doors.

1,520 sq m floors though, so under the magic 2000.

[CivvyFSO]

In ADB for office purpose groups it allows for no compartmentation between different occupiers, and for no compartmentation limits on the size of the building. (Until you get over 30m or want phased evacuation)

[kurnal]

Hi Civvy
You are indeed correct- the requirement for comparmentation between different users only applies specifically  to shop and commercial, industrial and storage premises and not to the office purpose group.

So the situation described by Anthony appears to be OK- to comply with ADB the lift shaft does not need fire doors and may be unprotected if:
a- the spaces are open plan unless it is necessary to pass within 4.5m of the lift shaft to reach the exit or
b- travel distances are such as to require a protected route leading to the staircase and this route incorporated the lift shaft

and in either of the above two cases do apply the lift doors could be FD30 or E30 with no requirement for smoke seals and no lobbies.

Assuming I am right, In Anthony's scenario, and with regard to ADB para 3.12 on page 36,  assuming the lift shaft is closer than 4.5m to the staircases, and the offices are completely open plan I would say that the two lift shafts connect the same open spaces and so the second staircase does not provide an alternative escape route as described in 3.12.b. And so FD30 lift doors are required. Would you agree?

Not a day goes by that I do not have to re-learn something I thought I already knew!

[AnthonyB]

Sounds about right, the lifts are about 1.5 to 2m from the storey exits & are open plan.

Based on final letting you will either have a whole open floor with one protected stair incorporating two lift shafts within and two alternatives, each with these lifts adjacent open to the floor, or subdivided so each wing has access to the main stair and one of these alternatives.

also another oddity is that the central stair has a dry rising main- not odd you dry, but actually there are TWO dry rising mains in the same service riser shaft right next to each other so that each floor has two adjacent outlets off different pipes in the same cupboard!