Escape through partially open car park?

[muggins]

Imagine two apartment blocks squeezed into a residential area - very limited road frontage.  The two blocks are separated at the centre of the site by a partially open car park - a sort of courtyard.  This is accessed through an arch from the road. It has parking for 5 cars.  It is a very tight design.
Both blocks have a single stair, are of 3 stories with an apartment on each floor.  The stairs from the rear block are lobbied at groudn floor, and open into the open air i.e. the car park courtyard.   From there the occupants would have to escape down the side of the parking spaces under the arch to the road.  
Is this a reasonable proposal?  It seems to come down to the definitiion of place of safety i.e. is the open air in the car park acceptable?
Otherwise the travel distances will be exceeded and the location of the stairs woudl have to be altered.  The buildings are at design stage.
The other problem is that the road way under the arch is too narrow for fire brigage.  
Any comments appreciated thanks

[Ricardo]

Muggins

Open air "away from the building" is key,  I've heard it said in the past that 1 and a half times the building height away is reasonable or at least 10 metres away, as a place of safety, since this is a proposal that will be required to comply with the Building Regulations, the height of the buildings will no doubt require dry riser inlets for fire service use, and fire appliances should be able to get to within 18 metres of these inlets, otherwise if the height is such that no dry risers are required then 45 metres is taken as a reasonable distance away for fire tenders.
So access under the arch may not be necessary for fire service use.

[Dragonmaster]

What about domestic sprinklers (to BS9251)? This will probably remove the need for FS access to comply with ADB, as water is already being put on the fire, and the archway no longer becomes a problem. You may get away with other relaxations as well.

[Ken Taylor]

These issues can come down to the professional judgement of planners, Building Control/AIs and the local fire authority but the layout sounds more like a number of historic/older buildings than new-build design. Will the evacuated occupants be safe in the presumably small carpark if the building is on fire? Will there be any impediment to further evacuation through the arch? Is someone going to install gates to the arch for security purposes? Will there be a designated pedestrian escape route through the carpark (eg with road markings/hatching or barriers)? A number of factors seem to need consideration on this one. If you can get residential sprinklers installed we will all applaud the decision.

[kurnal]

If persons can escape via the car park to a place of ultimate safety away from the site via the arch this should not be too much of a pproblem.

If the site is as tight as it sounds is there a significant risk of a car fire adjacent to the building- causing penetration of the building via the windows and to the escape routes at the same time?

Fire Service access under B5 may well be the big problem here as others have pointed out. There are a number of examples where this has been traded off for residential sprinklers and a number of local authorities have now produced documents showing their accepted trade offs- If you struggle to find these through google let us know and I will point you in the right direction (have downloaded some at the office)

[slubberdegullion]

Nearly everything has been covered here.  I'd just add, yes, of course, go for the domestic sprinklers in the first instance as compensation for the poor fire service access, but if you fail to negotiate that watch out for horizontal risers like this where there is some horizontal distance between the inlet and the staircase containing the outlets.  I think this is discussed under another topic on this forum.  If not, maybe it should be.

In this particular case it sounds as though this horizontal distance might be quite short and might be acceptable, but long distances must not be allowed without additional compensation as they require firefighters to carry all their equipment (bolt croppers, hose, branches, BA sets, resuscitator, etc) that extra distance - it's not just the water we're interested in, is it?

Stu

[muggins]

Thanks for the advice. This is my first time using the forum, just like to say it is really useful.  I think I knew the answers to the questions before I posted them, but wanted some additional confirmation.  The escape route through the car park woudl be compromised as the route passes within 2m of a parked car.  Also, if a car was burning in the car park, there woudl be no way you coudl have ladder access to upper windows.  The archway is too narrow to allow a car and person to pass at the same time.  You are right Ken that it does sound like a historic layout - it is almost like a georgian house with mews building and car park between.  The only problem is that it is still on paper, badly designed and not going to pass fire regs!  Back to the drawing board in my opinion

[slubberdegullion]

If a car was on fire in the car park why would you want to pitch a ladder to an upper storey?

Stu

[nearlythere]

Thanks for the advice. This is my first time using the forum, just like to say it is really useful.  I think I knew the answers to the questions before I posted them, but wanted some additional confirmation.  The escape route through the car park woudl be compromised as the route passes within 2m of a parked car.  Also, if a car was burning in the car park, there woudl be no way you coudl have ladder access to upper windows.  The archway is too narrow to allow a car and person to pass at the same time.  You are right Ken that it does sound like a historic layout - it is almost like a georgian house with mews building and car park between.  The only problem is that it is still on paper, badly designed and not going to pass fire regs!  Back to the drawing board in my opinion

Muggins.
Consider this? A shop or office, multi-storey, with one way out - the front door onto a public pavement and roadway. Just outside the front door, certainly within 2M of the door, is a line of legally parked motorcycles, or cars, or a kosangas delivery lorry, or a petrol tanker. Is this worse than your situation? Is this not the situation in practically every street in the country every day?
Why is it a problem when it is a private car park?

[muggins]

lateral thinking.  Could be worth a try.  The problem is that there is no access to the rear of the rear block.  So if there is a fire in the courtyard car park, it might block the exit from the stairwell.  Then if you cant put a ladder up there, you cant get people out through the windows so they would be trapped.  

The main difference between this and a car parked on the street is the fact that the site is so congested.  two cars woudl be parked under the rear block and two would be in the open courtyard between the two blocks.  There are buildings on the sites to the side, so natural cross ventilation would be difficult, and my worry would be that the courtyard would function like a big chimney if a car was on fire there.  

I will have another think about this over Christmas....

[CivvyFSO]

I park about 1 metre from my front (And only) door. BUT, I am lucky enough not to have a car that randomly bursts into flames.

BUT... Just for the record... If it somehow did end up on fire, my family and I would like to remain in our house until the fire service have extinguished the fire please. (Then I would like to walk out of my front door)