The Ontario Building Code | Emergency Access to Floor Areas
3.4.6.18. Emergency Access to floor Areas
(1) In a building more than 6 storeys in building height,
(a) except as permitted by Sentence (3), doors providing access to floor areas from exit stairs shall not have locking devices to prevent entry into,
(i) any floor area designated as an area of refuge,
(ii) floor areas located at intervals of 5 storeys or less, and
(iii) at least one of the three highest storeys,
(b) doors referred to in Clause (a) that provide access into the floor area shall be identified by a sign on the stairway side to indicate that they are openable from that side, and
(c) a master key to fit all door locking devices that are intended to prevent entry into a floor area from an exit stair shall be provided in a designated location accessible to firefighters, or the door shall be provided with a wired glass panel not less than 0.0645 m2 in area and located not more than 300 mm from the door opening hardware.
(2) If access to floor areas through unlocked doors is required by Clause (1)(a) or through electromagnetically locked doors as permitted by Sentence (3), it shall be possible for a person entering the floor area to have access through unlocked doors or through electromagnetically locked doors within the floor area to at least one other exit.
(3) Electromagnetic locking devices may be installed on the doors providing access to floor areas from exit stairs as required by Clause (1)(a), provided all locking device release and signage provisions in Sentence 3.4.6.16.(4) are installed on both sides of the doors.
(4) In a building not more than 6 storeys in building height, doors providing access from exit stairs to a floor area containing a hotelare permitted to have locking devices to prevent entry into the floor area provided the requirements in Clause (1)(c) are complied with.
In Plain Language
In buildings more than 6 storeys tall, doors from exit stairs back into floor areas generally can't have locking devices that would prevent re-entry into designated areas of refuge or specific floor levels, so occupants aren't trapped in a stairwell during a phased evacuation.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.