Just had a recent visit from fire safety officer.........

[hammer1]

To a Restaurant/Banquet and he has stated that the occupancy levels should be 320 max, it currently stands at 450 and has done since 1990. Obviously what he has done (I have no full details as yet) to take 1 of the 2 escape routes out of the equation as you do for worse case scenario, measured the width of remaining exit and got his figure 320. The 450 figure came from the angle of floor space per person occupancy levels.

All other issues seems like he was happy with.

I know it is very basic info, but I would like suggested arguments/response to keep occupancy levels at 450 otherwise the business will shut. 

The FRA did not highlight this as an issue and only stated the m2 area per person for floor space.

[kurnal]

It always has been standard practice to discount the widest exit as part of the capacity calculations.

One storey exit is always discounted. Theres no way round that. I take it you only have two exits available from the restaurant?

The chances are that the Officer has used rule of thumb calculations based on a 2.5 minute evacuation time. Is this appropriate or are there other features that may mitigate a little?

What floor is it on?
What is the construction of the building?
How high is the ceiling?
Details of decorations and surface finishes?
Fire alarm and detection system - to what standard?
Sprinkler system fitted?
How good is the management response to a fire alarm?
 

[hammer1]

It always has been standard practice to discount the widest exit as part of the capacity calculations.

One storey exit is always discounted. Theres no way round that. I take it you only have two exits available from the restaurant?

The chances are that the Officer has used rule of thumb calculations based on a 2.5 minute evacuation time. Is this appropriate or are there other features that may mitigate a little?

What floor is it on?
What is the construction of the building?
How high is the ceiling?
Details of decorations and surface finishes?
Fire alarm and detection system - to what standard?
Sprinkler system fitted?
How good is the management response to a fire alarm?
 

You are right in where he is coming from. Only 2 exits
Basement floor, low ceiling, L2 system, no sprinkler, very good management response.Structure is traditional brick work wall, Modern day plaster board skimmed finish, FD30S separation. Kitchen is 1 hour separation from the Restaurant.

Pretty much like most basement clubs, Pubs, Restaurants. However decreasing occupancy levels will make it no longer financially viable would therefore shut down. Not much risk assessing and taking other issues into account here. Surely they will not whack us with an enforcement notice on this, especially a Prohibition one

[hammer1]

I must also state that the Restaurant is a tenant of the basement and is part of a large building, which may have some listed status which would make major structure/feature adjustments difficult and also the main Landlord Resp.

[kurnal]

Basements are always bad news - poor ventilation, low ceilings.Conditions soon become untenable even with a small fire. Can the existing exits be widened at all? I assume from what you say at least one of the exits is 1600mm wide.

No chance of putting in an extra exit? For the extra 130 persons to get to 450  you would need another door about 1000mm wide and sited away from the other exits, or alternatively make both existing exits about 2250mm wide.

[kurnal]

Just to put it another way, the accepted benchmark for the capacity of your exits is that everyone should be able to pass through them within 2.5minutes. It would take 3.5 minutes for everybody to pass through your existing exits.

In simplistic terms this is a problem. You may be able to show it is not a problem if you can prove by calculation that in a fire situation the conditions remain tenable for more than 3.5 minutes (doubtful in a basement) and that a fire will be detected in its incipient stages, the alarm wll be raised immediately and that people will respond immediately and in a well controlled way. But this too is doubtful in a multi occupied building.

I suppose there are no compartment walls in the basement through which another exit could be provided?

Bring back that risk assessor and tell them to find a solution. This is bread and butter stuff and should have been picked up.

[CivvyFSO]

If I were working on the other side of the fence I would be looking at the following for this:

BS9999 gives 4.1mm per person for the B2 risk profile that seems to suit this occupancy
If you can say that there is a specific benefit from the L2 system you can shave a further 15% off giving 3.4mm per person
450 people x 3.4mm = 1530mm exit required

using BS9999 makes the management levels important, as this becomes an inherent part of the safety. But it is at M2 level of management, which is really a level that a premises should be at in order to comply with the RRFSO anyway. I would ensure that the restaurant has a list of the requirements of M2 management and are told that they need to be able to demostrate that they are fulfilling those requirements.

Personally I dislike BS9999 for various reasons, but people are willing to accept it and if it all goes wrong you can probably blame the British Standards people.

Other considerations would be:
Use of a voice alarm
Fire retardancy of decorations/furniture etc leading to a slow fire growth
Potential for a suppression system in the kitchen

[Tom W]

As Kurnal said, this is the job of the risk assessor to provide solutions.

If the building is indeed listed, you will have difficulties as a good avenue to explore is widening the exits.

There will always come a time though that maybe you will have to agree with the FSO and accept 450 is not acceptable without building modifications.

Try and find a paper trail, who said it was 450 in the first place? Does he own or rent the property? What does the lease say? When was the last time it was inspected? Any paperwork?

[hammer1]

Basements are always bad news - poor ventilation, low ceilings.Conditions soon become untenable even with a small fire. Can the existing exits be widened at all? I assume from what you say at least one of the exits is 1600mm wide.

No chance of putting in an extra exit? For the extra 130 persons to get to 450  you would need another door about 1000mm wide and sited away from the other exits, or alternatively make both existing exits about 2250mm wide.

It is a Grade 2 listed building, so any major alterations would be very difficult and would need Landlord approval.

[Davo]

hammer1

As the Prof says, your RA dropped the ball, so I think you will have to reduce numbers if the alternatives are a non-runner.
Even if the old certificate says 450 and nothing in Doc B has changed in regard to numbers, I still think the FSO has a fair point in the scenario given

davo

[Phoenix]

I would definitely go down the road Civvy has suggested.  But I'd be careful about applying the additional 15% allowance for the fire alarm system.  

I know that the minimum level stipulated is manual and that this place has L2 but it's not always the case that there is actual proven benefit, in terms of means of escape, in having the additional detection.  

The likelihood of a fire in the main room being spotted by a person increases as the occupancy increases so the greater the life risk the earlier the warning of fire will come.  The only real advantage the L2 system might have is that it will warn of a fire in an unoccupied back room somewhere.  Now, unless there are some serious compartmentation issues in the building, there's a good chance that such a fire is separated from the main body of people and their escape routes and so presents less of a threat to the occupants than a fire in the main room.  Therefore the advantage given by the L2 coverage is redundant as it only reduces a less risky scenario and not the one we're really interested in, i.e. the worst case scenario of a fire in the room where the people are.

All buildings are different and in some there is a case for allowing the 15% advantage but never forget that there has to be a proven benefit.  The voice alarm that Civvy mentioned might give that benefit.

I would reiterate Civvy's point that the management of the premises must be up to 9999 standards if the figure of 4.1mm/person is to be adopted.  If the door is 1600mm (which is implied) then 4.1mm/person gives an occupancy of 390.  

Put the voice alarm in, ensure management is as per 9999 and a 1600mm door is ok for 1600/(4.1 x 85%) = 459.

Stu

ps I don't much like it either, but there it is.

[hammer1]

Thanks Chaps,

I have  since seen the FRA and it does fail dramatically in regards to occupancy, assessing persons at risk which is shocking considering it is a Restaurant/Banquet, it is also misleading which is not the fault of the RP.

There is plenty to consider 1st which a few of you have brilliantly also identified. Good to see competent risk assessing is alive and kicking and not just (copy and paste/ quote) prescriptive  guidance, which was the whole point of introducing FSO.

Will let you know results.

[kurnal]

The chance of ensuring the other building users and Landlord have management to the M2 standard is  pretty remote. I haven't seen the building and am only going on the description so far. And despite the degree of management, getting people to copoerate with instructions quickly in a licensed building is easier said than done.

Like Phoenix I hate using reverse risk assessment in this way to find an excuse for not doing something that my gut feeling says needs to be done.

One of the best sources of information giving full background information on these topics is the CIBSE guide E-  Fire Engineering. My old 2003 edition has the following ISBN - 1 903287 31 6

[kurnal]

The ISBN of the 2010 edtion of CIBSE Guide E is  ISBN 978 1 906846 13 8