Mezzanines and fire sprinkler allowances

The installation of automatic fire sprinklers allows for many design advantages but the allowance for mezzanines is an ideal way to increase usable interior space and expand a business, at minimal cost.

The International Building Code (IBC) defines a mezzanine as an intermediate level or levels between the floor and ceiling of any story. They do not contribute to the overall building area or number of designated stories. This is the key to the real benefit to the allowance. It does not increase the overall square footage of the building while creating additional usable space. The area of the mezzanine must be included in determining fire area and shall have a minimum clearance of 7 feet. The addition of an equipment platform to the mezzanine only adds to the overall benefit. Equipment platforms are also defined in code as an occupied, elevated platform used exclusively for mechanical systems or industrial process equipment, including the associated catwalks, stairways, altered tread devices and ladders necessary to access the platform.

Mezzanines are often prefabricated modular designs allowing for lower installation cost options in buildings where owners seek addition space. The cost savings over moving into larger spaces or full renovations can be substantial.

The IBC area limitation for total aggregate area of a mezzanine allowance shall not be greater than one-third of the floor area of a room or space in which it is installed. The simple addition of an automatic fire sprinkler systems increases that allowance to one-half and where a room contains both a mezzanine and equipment platform in a type I or Type II construction, the original allowance is increased to two-thirds. This benefit in a building 60,000sf adds an additional 40,000sf of usable space for a total of 100,000 sf within that 60,000sf building.

The ability to maximize space with the addition of mezzanines and equipment platforms has many advantages beyond just adding usable square footage, including not increasing your actual square footage for tax implications, no operational cost increases for lighting and HVAC requirements, and customization.

Additional automatic fire sprinkler design advantages can be found in the new 2021 Fire Sprinkler guide: International Building Code Edition. Currently available in our store.