408.4 Locks.

Egress doors are permitted to be locked in accordance with the applicable use condition. Doors from a refuge area to the outside are permitted to be locked with a key in lieu of locking methods described in Section 408.4.1. The keys to unlock the exterior doors shall be available at all times and the locks shall be operable from both sides of the door.

408.4.1 Remote release.

Remote release of locks on doors in a means of egress shall be provided with reliable means of operation, remote from the resident living areas, to release locks on all required doors. In Occupancy Condition 3 or 4, the arrangement, accessibility and security of the release mechanisms required for egress shall be such that with the minimum available staff at any time, the lock mechanisms are capable of being released within 2 minutes.

   Exception: Provisions for remote locking and unlocking of occupied rooms in Occupancy Condition 4 are not required provided that not more than 10 locks are necessary to be unlocked in order to move occupants from one smoke compartment to a refuge area within 3 minutes. The opening of necessary locks shall be accomplished with not more than two separate keys.

408.4.2 Power-operated doors and locks.

Power-operated sliding doors or power-operated locks for swinging doors shall be operable by a manual release mechanism at the door. Emergency power shall be provided for the doors and locks in accordance with Section 2702.

   Exceptions:

      1.   Emergency power is not required in facilities with 10 or fewer locks complying with the exception to Section 408.4.1.

      2.   Emergency power is not required where remote mechanical operating releases are provided.

408.4.3 Redundant operation.

Remote release, mechanically operated sliding doors or remote release, mechanically operated locks shall be provided with a mechanically operated release mechanism at each door, or shall be provided with a redundant remote release control.

408.4.4 Relock capability.

Doors remotely unlocked under emergency conditions shall not automatically relock when closed unless specific action is taken at the remote location to enable doors to relock.

408.5 Protection of vertical openings.

Any vertical opening shall be protected by a shaft enclosure in accordance with Section 713, or shall be in accordance with Sections 408.5.1 and 408.5.2.

408.5.1 Floor openings.

Openings in floors within a housing unit are permitted without a shaft enclosure provided all of the following conditions are met:

   1.   The entire normally occupied areas so interconnected are open and unobstructed so as to enable observation of the areas by supervisory personnel;

   2.   Means of egress capacity is sufficient for all occupants from all interconnected cell tiers and areas;

   3.   The height difference between the floor levels of the highest and lowest cell tiers shall not exceed 23 feet (7010 mm); and

   4.   Egress from any portion of the cell tier to an exit or exit access door shall not require travel on more than one additional floor level within the housing unit.