R325.5

Section R325.5 is titled 'Openness' and covers requirements for mezzanines. The requirement for mezzanines to be mostly open to the room they are located in is established. The purpose of this section is to minimize small areas which are typically used for recreation and sleeping, which could quickly subject the occupants to smoke inhalation in the event of a fire. This section has 2 exceptions which allow for small areas of a mezzanine to be enclosed, or, where the building is limited in stories and has specific safety features for the entire mezzanine to be closed from the room it is located. The purpose of these exceptions is to allow for areas such as closets or bathrooms to be separated from the mezzanine, and to allow for entirely closed mezzanines where arrangement and features of construction reduce the risk of smoke accumulation within the mezzanine.

The model shows a mezzanine which is open to the room it is located in.