• Regardless of the occupant load served, exit doors shall be openable from the inside without the use of a key or any special knowledge or effort.

EXCEPTIONS: 1. In Groups A, Division 3; B; F; M and S Occupancies and in all churches, key-locking hardware may be used on the main exit where the main exit consists of a single door or pair of doors where there is a readily visible, durable sign on or adjacent to the door stating, "THIS DOOR MUST REMAIN UNLOCKED DURING BUSINESS HOURS." [for SFM] THIS DOOR TO REMAIN UNLOCKED WHENEVER THE BUILDING IS OCCUPIED. The sign shall be in letters not less than 1 inch (25 mm) high on a contrasting background. When unlocked, the single door or both leaves of a pair of doors must be free to swing without operation of any latching device.

The use of this exception may be revoked by the building official [for HCD 1 & 2] enforcing agency for due cause.

2. Exit doors from individual dwelling units; [for SFM] buildings or rooms; Group R, Division 3 congregate residences; and guest rooms of Group R Occupancies having an occupant load of 10 or less may be provided with a night latch, dead bolt or security chain, provided such devices are openable from the inside without the use of a key or tool [for SFM] or special knowledge or effort and mounted at a height not to exceed 48 inches (1219 mm) above the finished floor.

3. [For SFM] Mental, penal or corrective institutions where supervisory personnel are continually on duty and effective provisions are made to remove occupants in case of fire or other emergency.

EXCEPTIONS: 1. Group R, Division 3 Occupancies.

2. Where a pair of doors serving a room not normally occupied is needed for the movement of equipment, manually operated edge- or surface-mounted bolts may be used.