A mezzanine is an intermediate level between the floor and ceiling of any story. In regards to the building code, mezzanines must comply in accordance with Section 505.2 of the International Building Code (IBC).
A mezzanine in compliance with Section 505.2 shall be considered a portion of the story it serves below. Such mezzanines do not need to contribute to either the building area or number of stories as regulated by Section 503.1, when determining how big or tall a building can be. However, even though it is not factored into the building area, its square footage shall be included when determining the fire area.
505.2.1 Mezzanine Area Limitation (Limited Area)
The minimum height of a mezzanine should be no less than 7 feet high. This is to ensure safety, just as well as the space feeling open and spacious, not cramped or claustrophobic.
How big can a Mezzanine floor be?
The total area of a mezzanine within a room shall be no greater than 1/3 the floor area of the room in which it is located. However, there are some exceptions to this rule that can allow for more space on top and below if certain factors such as building type construction and sprinkler system require it.
505.2.2 Means of Egress for Mezzanines (Exiting)
The means of egress for mezzanines must follow the rules for Chapter 10. A mezzanine is a space with an occupant load (a person). The code requires that you make sure people can get out of it easily by following the rules in Chapter 10.
A mezzanine is an area that can be used as a room or space if it has the appropriate occupant load. Mezzanines are not required to have any additional exiting requirements, but must abide by other code regulations such as egress rules in Chapter 10 of the International Code Council’s building codes (ICC).
505.2.3 Mezzanine Openness
A mezzanine is a raised area that spans the width of a room and does not touch any other structure. The design will be open to anyone entering, except for walls no more than 42 inches high.
Can a Mezzanine be Enclosed?
If your project includes an enclosed mezzanine, then you need to take additional steps to ensure that the space meets building code requirements. The code does allow for some exceptions related to the “openness” of a mezzanine. If you meet these criteria, then your mezzanine space doesn’t have to be open at all – one exception would be if it’s occupant load is not more than 10 and another would be if there are two exits out of that room or area. In this case, an enclosed portion could still exist in any given floor plan design.
Summary of Mezzanine Code Requirements
– A mezzanine is an intermediate level between the floor and ceiling of any story.
– The clear height above and below a mezzanine shall not be less than 7 feet.
– The total area of a mezzanine within a room shall be not greater than 1/3 the floor area of the room in which it is located.
– The means of egress for mezzanines shall comply with the applicable provisions of Chapter 10.
– A mezzanine shall be open to the room in which it is located or enclosed depending on the occupant load or number of exits serving the mezzanine space as noted above.
– A mezzanine in compliance with Section 505.2 shall be considered a portion of the story it serves below and does not need to contribute to either the maximum allowable building area or number of stories as regulated by Section 503.1, however its square footage shall be included when determining the fire area.