There are various norms which need to be followed. Among them, the major one is having two staircases. If you recall during the old times everyone used to have two exits to their houses; one ahead and one at the back. The staircase should be at least 1.5 meters in length so that people can easily pass through. In case a factory constructs a basement then they should have a sprinkler system in place. A water zeal should also be in place in case a fire needs to be doused during the time the fire extinguisher arrives.
Apart from this, fire extinguishers, hydrant pump and water tank should also be present. Only if all these norms are followed, will we issue a fire NOC.
The problem is that most of the buildings are different from the structural plan. While some have got their plans sanctioned but have ended up building extra floors and basement and eventually have covered up most of their open areas.
The authorities need to make sure that the owners don’t build beyond what is allotted to them. Also many of them do not even apply as they know they would be not be granted.