The building code sorts the ways that buildings are used into separate "occupancy classifications". Every building is given an occupancy classification when it is built, and each occupancy classification has different building code requirements that go along with it. A "change of occupancy" is when there is a change in the building's use that would place it in a different occupancy classification.
A change of occupancy to an assembly occupancy will require that the building/space meet most of the current building code requirements for a new building. This will likely mean adding more exits, emergency lighting, or other safety improvements. You will probably also be required to add more restrooms to serve the increased number of occupants.
The building code classifies a coffee shop/café/restaurant as one of two "occupancies". "A2 occupancies" are where there is a room with 50 or more occupants, as calculated by the code. In general, a table and chair seating area larger than 750 square feet will result in an A2 occupancy classification. A drinking and dining establishment with a seating area of less than 750 square feet can be classified as a "B occupancy", which has much less restrictive requirements. A 750 square foot table and chair seating area is assumed, by the code, to have 50 occupants. Where there are dance floors or similar "standing" areas, the occupant load will add up a lot faster. Open areas intended to be used by patrons, but without furniture, are looked at as being occupied even more densely than standard seating areas.
Once the occupant load reaches 100, then the establishment is required to have a sprinkler system. 100 occupants is the equivalent of a table and chair seating area of 1500 square feet.
You can expect to make some significant life safety improvements to any building that you are changing the occupancy to assembly, including:
- two well separated exit doors that swing out in the direction of exit travel,
- an emergency power system that keep the exit ways lit in case of power failure, and
- in almost all cases, a fire separation is required between assembly occupancies and any other uses in the building.
For more information on how the occupant load of your particular use might be calculated, and what types of life safety improvements might be required, visit the Development Services Center with a rough layout, and meet with a Life Safety Reviewer.