As I understand it, if both doors were compliant, then assuming normal risk, the maximum occupancy would be 100 (2.5 minutes, 40 people per minute). However as they are not, and as the standard method is to assume one exit will be unavailable am I correct in thinking that the maximum occupancy must be reduced accordingly to 60, (since it would be wrong to assume the compliant exit will be the available one)?
No Meerkat, the interpretation I was taught was that if there are two fire exits from a room, then the widest exit is discounted and the capacity is based on the width of the remaining door. Three exits, widest is still discounted and the occupancy based on the capacity of the two remaining doors etc. It is not based on the idea that if there are two exits and one exit is discounted, then the figure used is for a single exit only i.e. 60.
However have a look at ADB 5.14 Direction of opening: 'The door of any doorway or exit should, if reasonably practical, be hung to open in the direction of escape and should always do so if the number of persons that might be expected to use it at the time of a fire is more than 60.'
Where does this leave you? In my view, maximum of 60 based on ADB, as you might reasonably expect the other exit to be unavailable. If the door can be turned round then it will be based on the exit capacity.