How does the Fire Marshal Determine the Maximum Occupancy of Rooms?

Some of us might be curious about such basic things. Others might dismiss these issues as boring and unimportant. However, there are some solid reasons for limiting the number of people who can occupy an indoor space.

When we see a sign in a large banquet room that says: Maximum occupancy – 300, what process was used to come up with this number?

You can be sure that the fire marshal didn’t just stand at one end of the empty space and say, “This room looks like it could hold about 300 people.” In fact, the first step this official will take involves measuring the room to determine how many square feet of space are available (length x width). Ceiling height is also taken into consideration.

In addition to the basic measurements, the fire marshal will make note of structures, such as columns, raised areas such as a stage, bar, cabinets etc. If there are large, heavy pieces of furniture that probably won’t be moved, this is taken into consideration as well.

All of this information is used to determine an occupancy number. But the data is used in combination with a key question: How many people can use this room at one time but still be able to exit quickly and efficiently in case of emergency?

At this point, the fire marshal determines the number and location of exits. If there is only one exit the maximum occupancy number will be smaller. It makes sense to limit the number of people who would have to get through one door in an emergency. If there are two, three or four clear exits it will obviously be much easier for people to get out of the space. Time is a key factor in determining maximum occupancy numbers.

The fire marshal and insurance personnel will also consider the intended use of the room. The number will be different for an open dance floor as opposed to a restaurant with numerous tables or a wedding reception with tables and chairs in place. This information affects how many people will fit comfortably in the space, of course. But it also affects how they will move and exit.

In addition to these factors, a fire marshal may look at such items as overall room lighting and the lighting/signing of exits. If doors, windows, stairways and elevators are all clearly visible and well lit, it will be a safer room in an emergency. The fire marshal will also consider the sale of alcoholic beverages when determining safe use of open space. It may be necessary to limit the maximum number of persons in this situation.

The process of measurement, exit assessment and other procedures usually takes place after a property owner applies for a use permit or an occupancy permit. Signs indicating maximum occupancy must be clearly displayed.
Maximum occupancy numbers are designed to serve and protect the people using the facility.