CarlyD
Required exit widths are worked out to keep a nice flow of people through the exits at a speed that we would move through an exit unhindered, and generally aim towards a potential 2.5 minute evacuation.
Just to demonstrate from your figures working from exit widths suggested in ADB:
>>one at 1000m<<
You should get 110 people through this exit in 2.5 minutes
>>one at 1100mm<<
You should get 220 through this exit in 2.5 minutes
>>and one at 1200mm. <<
You should get 240 through this exit in 2.5 minutes.
Looks like if your measurements are correct then an occupancy of 570 would be appropriate as per Approved Document B. (This is just an example working from the figures you gave.)
Floorspace would suggest that the building could hold at least 2800 persons. (1400m2 at 0.5m2 per person = 1400/0.5=2800) At 5mm per person that would require 14metres of exit width. (After discounting the largest exit)
At present, if you were to occupy the club to a capacity of 2800, in the event of an emergency your exits can allow out 228 persons per minute. (570 persons takes 2.5 minutes, so 570/2.5 = 228 persons per minute)
So 2800 persons, 228 per minute means 2800/228 = number of minutes necessary to evacuate your club.
2800/228 = 12.3 minutes
As you might imagine, this would not be good.
To throw another light on it: To have enough exits for your potential capacity look at your biggest door available so far; The 1200mm door can allow 240 persons through in 2.5 minutes.
2800 capacity / 240 persons = 11.66
That means you really need 13 of those 1200mm exits (The extra one is to discount) to allow these people out effectively.
Sorry if I have gone on a bit, but I think it demonstrates the difference between having adequate exits, and not having adequate exits.