High buildings, emergency lighting and power, floor openings and testing (Fire Protection)

Last updated October 22, 2026

Values this chapter turns on

top floor height making A, D, E or F high: 36 m; top floor height making A, D, E or F high
average emergency lighting level in exits: 10 lx; average emergency lighting level in exits
emergency lighting run time, high buildings: 2 h; emergency lighting run time, high buildings
minimum depth of draft stops at floor openings: 500 mm; minimum depth of draft stops at floor openings

This chapter groups four topics that interlock: the extra measures for high buildings (3.2.6. and Supplementary Standard SB-4), emergency lighting and emergency power (3.2.7., without the normal lighting levels in 3.2.7.1.), interconnected floor spaces such as atriums (3.2.8.3. to 3.2.8.8.), and integrated testing of fire and life safety systems (3.2.9.). Many questions are about which buildings are caught and how long things must run.

High buildings and smoke control (SB-4)

Subsection 3.2.6. applies to (OBC Div. B 3.2.6.1.):

Building	Applies when
Group A, D, E or F	top storey floor more than 36 m above grade, or more than 18 m with heavy stair loading (occupant load over 300 per 1.8 x stair width)
Group B	highest Group B storey floor more than 18 m
Group B2 or B3	any floor area above the third storey
Group C	highest Group C storey floor more than 18 m
Retirement home	highest storey floor more than 18 m
Mass timber (3.2.2.57., 3.2.2.93.)	highest storey floor more than 18 m

Note these heights are measured to the floor of the top storey, not the ceiling (unlike the 14 m standpipe trigger).

Smoke movement (3.2.6.2.). A sprinklered high building is designed under Sentences (2) to (6) and SB-4. Exit stairs below the lowest exit level must stay below 1% contaminated air for 2 h. Each stair serving storeys above the lowest exit level has a manually openable vent at the bottom: 0.05 m² per door into the stair, at least 1.8 m². Air-moving fans serving more than 2 storeys can be stopped from the central alarm and control facility. Unsprinklered high buildings are designed fully to SB-4. SB-4 commentary explains the stack-effect logic and recommends at least 12 Pa where stairs are pressurized mechanically (SB-4, 3.2.6.2.(3)).

Other high building features:

manual emergency recall for elevators above the first storey, automatic recall if unsprinklered (3.2.6.4.);
a firefighters' elevator: 2.2 m² platform, 900 kg to the top floor within 1 min, protected by a 1 h closure, 45 min vestibule or 1 h corridor (3.2.6.5.);
venting of each floor area by windows, panels, smoke shafts or the exhaust system (not hoistways) (3.2.6.6.);
a central alarm and control facility on the firefighter access storey (3.2.6.7.);
a voice communication system where the top floor is over 36 m, B2/B3 is above the third storey, or a retirement home is over 18 m (3.2.6.8.);
smoke control and venting tested to SB-4 (3.2.6.9.).

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Emergency lighting and emergency power

Emergency lighting gives an average of 10 lx with a minimum of 1 lx in exits, principal routes to exits, public corridors, corridors used by the public, B2/B3 patient corridors, classroom corridors, assembly areas (A1, or A2/A3 with 60 or more persons), day care areas, commercial kitchens, public washrooms and more (OBC Div. B 3.2.7.3.).

How long emergency power must run:

Building	Emergency lighting (3.2.7.4.)	Fire alarm, after 24 h supervisory (3.2.7.8.)
Within 3.2.6.	2 h	2 h
Group B, retirement home, 3.2.2.51./3.2.2.60. (not 3.2.6.)	1 h	1 h
No annunciator required	30 min	5 min
Any other	30 min	30 min

Emergency power systems follow CSA C282, hospitals CSA Z32, and self-contained lighting units CSA C22.2 No. 141 (3.2.7.5.). A generator for 2 h at full load is needed for elevators in buildings over 36 m and firefighter elevators, fire pumps that depend solely on building power, and smoke control and venting fans (3.2.7.9.). In high buildings, conductors for fire alarm, emergency lighting and emergency equipment need a 1 h circuit integrity rating (CAN/ULC-S139) or a 1 h service space (3.2.7.10.).

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Interconnected floor spaces

An interconnected floor space is a set of floors linked by openings without closures. The package of protection (3.2.8.3. to 3.2.8.8.):

Measure	Requirement
Sprinklers	whole building; closely spaced heads and draft stops at openings per NFPA 13
Exit vestibules	doorways at least 1.8 m apart; keep exit stair below 1% contaminated air (3.2.8.4.)
Protected floor space	separated at the floor assembly rating, entered through vestibules (3.2.8.5.)
Draft stops	at least 500 mm deep at each level (3.2.8.6.)
Mechanical exhaust	4 air changes per hour, switch near the annunciator (3.2.8.7.)
Fuel load where ceiling over 8 m	not more than 16 g of combustibles per m³

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Integrated systems testing

Where fire protection and life safety systems are integrated with each other, for example a fire alarm that recalls elevators, releases doors and stops fans on a sprinkler flow signal, the systems are tested together to CAN/ULC-S1001 (OBC Div. B 3.2.9.1.). This is in addition to each system's own verification (such as S537 for the fire alarm).

Common traps:

Measuring the 18 m or 36 m high building trigger to the ceiling instead of the floor of the top storey.
Using the lighting duration for the fire alarm (they match except where no annunciator is needed: 30 min lighting versus 5 min alarm).
Thinking the interconnected floor space needs sprinklers only in the atrium.

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Chapter review

Chapter at a glance

One line per section: the idea to carry into the exam. Then the answers that most often catch candidates out.

Chapter at a glance: the key idea in each section
Section	Key idea
High buildings and smoke control (SB-4)	Note these heights are measured to the floor of the top storey, not the ceiling (unlike the 14 m standpipe trigger).
Emergency lighting and emergency power	Emergency lighting gives an average of 10 lx with a minimum of 1 lx in exits, principal routes to exits, public corridors, corridors used by the public, B2/B3 patient corridors…
Interconnected floor spaces	An is a set of floors linked by openings without closures.
Integrated systems testing	Where fire protection and life safety systems are integrated with each other, for example a fire alarm that recalls elevators, releases doors and stops fans on a sprinkler flow…

High buildings and smoke control (SB-4)
Note these heights are measured to the floor of the top storey, not the ceiling (unlike the 14 m standpipe trigger).
Emergency lighting and emergency power
Emergency lighting gives an average of 10 lx with a minimum of 1 lx in exits, principal routes to exits, public corridors, corridors used by the public, B2/B3 patient corridors…
Interconnected floor spaces
An is a set of floors linked by openings without closures.
Integrated systems testing
Where fire protection and life safety systems are integrated with each other, for example a fire alarm that recalls elevators, releases doors and stops fans on a sprinkler flow…

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Questions on High buildings, emergency lighting and power, floor openings and testing, in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

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Code cited in this chapter

Based on the official 2024 Building Code Compendium on ontario.ca.

OBC Div. B 3.2.6.1. Application
(1)Except as provided in Sentence (2), this Subsection applies to a building
(a)of Group A, D, E or F major occupancy classification that is more than
(i)36 m high, measured between grade and the floor level of the top storey, or
(ii)18 m high, measured between grade and the floor level of the top storey, and in which the cumulative or total occupant load on or above any storey above grade, other than the first storey, divided by 1.8 times the width in metres of all exit stairs at that storey, exceeds 300,
(b)containing a Group B major occupancy in which the floor level of the highest storey of that major occupancy is more than 18 m above grade,
(c)containing a floor area or part of a floor area located above the third storey designed or intended as a Group B, Division 2 or 3 occupancy,
(d)containing a Group C major occupancy in which the floor level of the highest storey of that major occupancy is more than 18 m above grade, or
(e)containing a retirement home, where the floor level of the highest storey of the retirement home is more than 18 m above grade.
(2)Except as required by Clause 3.2.6.1.(1)(c), this Subsection applies to a building or part thereof constructed in conformance with Article 3.2.2.57. or 3.2.2.93. in which the floor level of the highest storey is more than 18 m above grade.
Open OBC Div. B 3.2.6.1. in the code viewer
OBC Div. B 3.2.6.2. Limits to Smoke Movement
(1)A sprinklered building shall be designed in accordance with Sentences (2) to (6) and MMAH Supplementary Standard SB-4, "Measures for Fire Safety in High Buildings," to limit the danger to occupants and firefighters from exposure to smoke in a building fire.
(2)A building referred to in Sentence (1), shall be designed so that, during a period of 2 h after the start of a fire, each exit stair serving storeys below the lowest exit level will not contain more than 1% by volume of contaminated air from the fire floor, assuming an outdoor temperature equal to the January design temperature on a 2.5% basis determined in conformance with MMAH Supplementary Standard SB-1, "Climatic and Seismic Data."
(3)Each stairway that serves storeys above the lowest exit level shall have a vent to the outdoors, at or near the bottom of the stair shaft, that
(a)has an openable area of 0.05 m² for every door between the stair shaft and a floor area, but not less than 1.8 m²,
(b)opens directly to the outdoors or into a vestibule that has a similar opening to the outdoors, and
(c)has a door or closure that
(i)is openable manually, and
(ii)can remain in the open position during a fire emergency.
(4)Measures shall be taken to limit movement of smoke from a fire in a floor area below the lowest exit storey into upper storeys.
(5)Except for exhaust fans in kitchens, washrooms and bathrooms in dwelling units, and except for fans used for smoke venting as required by Article 3.2.6.6., air moving fans in a system that serves more than 2 storeys shall be designed and installed so that in the event of a fire these fans can be stopped by means of a manually operated switch at the central alarm and control facility.
(6)Except as provided in Article 3.2.4.12. or where there is a conflict with other smoke control measures in the building, air-handling systems used to provide make-up air to public corridors serving suites in a Group C major occupancy shall not shut down automatically upon activation of the fire alarm so as to maintain corridor pressurization.
(7)A building that is not sprinklered shall be designed in accordance with MMAH Supplementary Standard SB-4, "Measures for Fire Safety in High Buildings," to limit the danger to occupants and firefighters from exposure to smoke in a building fire.
Open OBC Div. B 3.2.6.2. in the code viewer
OBC SB-4 3.2.6.2. (3) Requirements for Stair Shafts Serving Storeys Above Lowest Exit Level
Open doors and vents at the bottom of a stair shaft that serve storeys above the lowest exit level, will create a positive pressure in the shaft relative to adjacent floor areas and thus prevent smoke infiltration into the shaft. This pressure differential, created as a result of the stack effect will be the greatest during the winter, when the difference in temperature between the interior and the exterior of the building is most pronounced. If a stair shaft does not have a direct opening to the exterior, alternative means must be provided to achieve the pressure differential and consequent smoke control. In the instance where a corridor or vestibule is used as a link between the exit level of an interior stair shaft and the outdoors, it will be necessary to assess the reliability and performance of the overall system in creating the necessary stairway pressurization. The probability of all doors or closures being opened at the same time, as well as the size of the vestibule and its impact on the overall smoke control system, are factors that need to be considered.
(1)Each stairway that serves storeys above the lowest exit level shall have a vent to the outdoors, at or near the bottom of the stair shaft, that,
(a)has an openable area of 0.05 m² for every door between the stair shaft and a floor area, but not less than 1.8 m² ,
(b)opens directly to the outdoors or into a vestibule that has a similar opening to the outdoors, and
(c)has a door or closure that,
(i)is openable manually, and
(ii)can remain in the open position during a fire emergency.
If mechanical methods are used to develop a positive pressure in a stair shaft, a minimum pressure differential of 12 Pa is recommended to prevent smoke migration from floor areas in a sprinklered building where fire temperatures are controlled and smoke movement may be dominated by stack effect in a stair shaft. During a fire emergency, persons will be entering and exiting a stair shaft as they move to a place of safety and under these conditions the number of doors open to the stair shaft cannot be predetermined. The number will vary depending on the occupancy of the building, population density and the evacuation plan for the building. It should be assumed that two doors are open. This is based in part as a practical level for most buildings and considers the positive fire experience in sprinklered buildings.
The maximum pressure differential created by a mechanical system should not prevent doors to the stair shafts from being opened. A specific maximum value cannot be given, as this value will depend on the door opening force and size of the door. These values should be calculated for each specific case. A maximum value of 130 N is suggested by research as the force that can be opened by the majority of people in most occupancies, however this value is above the maximum value of 90 N generally specified in this Code (Section 3.4. of Division B). The use of values below 130 N can create a practical problem in achieving effective smoke control as it is difficult to design for the acceptable minimum and maximum pressure differential range. Special consideration may need to be given to doors located in a barrier free path of travel.
Care should be taken by designers and by building and fire officials in implementation of these requirements. Assumptions involved in the design of a smoke control system may be different from final construction conditions. For this reason each system should be tested after installation to ensure that the design intent is met. The minimum pressure differential is not intended to apply to locations in stair shafts when nearby doors are open to adjacent floor areas.
Open OBC SB-4 3.2.6.2. in the code viewer
OBC Div. B 3.2.6.4. Emergency Operation of Elevators
(1)Manual emergency recall shall be provided for all elevators serving storeys above the first storey.
(2)Key-operated switches for emergency recall described by Sentence (1) shall be provided in a conspicuous location at
(a)each elevator lobby on the recall level, and
(b)the central alarm and control facility required by Article 3.2.6.7.
(3)In-car emergency service switches shall be provided in all elevator cars.
(4)Keys to operate the switches required by Sentences (2) and (3) shall be
(a)provided in a suitably identified box conspicuously located on the outside of an elevator hoistway near the central alarm and control facility required by Article 3.2.6.7., and
(b)kept at the central alarm and control facility.
(5)In a building that is not sprinklered, automatic emergency recall operation shall be provided for all elevators serving storeys above the first storey.
(6)The automatic emergency recall feature in Sentence (5) shall be actuated by
(a)smoke detectors installed in each elevator lobby on each storey, or (See Note A-3.2.6.4.(6)(a))
(b)the building fire alarm system.
(7)Smoke detectors in Sentence (6) shall be designed as part of the building fire alarm system.
Open OBC Div. B 3.2.6.4. in the code viewer
OBC Div. B 3.2.6.5. Elevator for Use by Firefighters
(1)At least one elevator shall be provided for use by firefighters in conformance with Sentences (2) to (6).
(2)The elevator referred to in Sentence (1) shall have a useable platform area not less than 2.2 m² and shall be capable of carrying a load of 900 kg to the top floor that it serves from a landing on the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4. and 3.2.5.5. within 1 min.
(3)Except where Measure K of MMAH Supplementary Standard SB-4, "Measures for Fire Safety in High Buildings," is used, each elevator for use by firefighters shall
(a)be provided with a closure at each shaft opening so that the interlock mechanism remains mechanically engaged and electrical continuity is maintained in the interlock circuits and associated wiring for a period of not less than 1 h when the assembly is subjected to the standard fire exposure described in CAN/ULC-S104, "Standard Method for Fire Tests of Door Assemblies,"
(b)be protected with a vestibule containing no occupancy and separated from the remainder of the floor area by a fire separation having a fire-resistance rating not less than 45 min, or
(c)be protected with a corridor containing no occupancy and separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 1 h.
(4)Except as permitted by Sentence (5), an elevator referred to in Sentence (1) shall be capable of providing transportation from the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4. and 3.2.5.5. to every floor that is above grade in the building and that is normally served by the elevator system.
(5)If it is necessary to change elevators to reach any floor referred to in Sentence (4), the system shall be designed so that not more than one change of elevator is required when travelling to any floor in the building from the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4. and 3.2.5.5.
(6)Electrical conductors for the operation of the elevator referred to in Sentence (1) shall
(a)be installed in service spaces conforming to Section 3.6. that do not contain other combustible material, or
(b)conform to CAN/ULC-S139, "Standard for Fire Test for Circuit Integrity of Fire-Resistive Power, Instrumentation, Control and Data Cables," including the hose stream application, to provide a circuit integrity rating of not less than 1 h. (See Note A-3.2.6.5.(6)(b))
Open OBC Div. B 3.2.6.5. in the code viewer
OBC Div. B 3.2.6.6. Venting to Aid Firefighting
(1)Means of venting each floor area to the outdoors shall be provided by windows, wall panels, smoke shafts or, except as provided by Sentence (5), the building exhaust system.
(2)Fixed glass windows shall not be used for the venting required by Sentence (1) if the breaking of the windows could endanger pedestrians below.
(3)Openable windows used for the venting required by Sentence (1) shall be permanently marked so that they are easily identifiable.
(4)Elevator hoistways shall not be designed for the venting required by Sentence (1).
(5)In a building that is not sprinklered, venting of floor areas required in Sentence (1) shall not be provided by the building exhaust system.
Open OBC Div. B 3.2.6.6. in the code viewer
OBC Div. B 3.2.6.7. Central Alarm and Control Facility
(1)A central alarm and control facility shall be provided on the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4. and 3.2.5.5. in a location that
(a)is readily accessible to firefighters entering the building, and
(b)takes into account the effect of background noise likely to occur under fire emergency conditions, so that the facility can properly perform its required function under such conditions.
(2)The central alarm and control facility required in Sentence (1) shall include
(a)means to control the voice communication system required by Article 3.2.6.8., so that messages can be sent to
(i)all loudspeakers simultaneously,
(ii)individual floor areas, and
(iii)exit stairwells,
(b)means to indicate audibly and visually alert signals and alarm signals and a switch to
(i)silence the audible portion of these signals, and
(ii)indicate visually that the audible portion has been silenced,
(c)means to indicate visually that elevators are on emergency recall,
(d)an annunciator conforming to Article 3.2.4.8.,
(e)means to transmit alert signals and alarm signals to the fire department in conformance with Article 3.2.4.7.,
(f)means to release hold-open devices on doors to vestibules,
(g)means to manually actuate alarm signals in the building selectively to any zone or zones,
(h)means to silence the alarm signals referred to in Clause (g) in conformance with Sentences 3.2.4.22.(2) and (3),
(i)means, as appropriate to the measure for fire safety provided in the building, to
(i)actuate auxiliary equipment identified in Articles 3.2.6.2., 3.2.6.3. and 3.2.6.6., or
(ii)communicate with a continually staffed auxiliary equipment control centre,
(j)means for two-way communications with every elevator car,
(k)means to indicate visually, individual sprinkler system waterflow signals,
(l)means to indicate audibly and visually, sprinkler and standpipe system supervisory signals and trouble signals,
(m)a switch to silence the audible portion of a supervisory signal or a trouble signal, and
(n)visual indication that the audible portion of a supervisory signal or a trouble signal has been silenced.
Open OBC Div. B 3.2.6.7. in the code viewer
OBC Div. B 3.2.6.8. Voice Communication System
(1)A voice communication system conforming to Article 3.2.4.22. shall be provided in a building if
(a)the floor of the top storey is more than 36 m above grade,
(b)a floor area or part of a floor area located above the third storey is designed or intended for use as a Group B, Division 2 or 3 occupancy, or
(c)a floor area or part of a floor area located more than 18 m above grade is designed or intended for use as a retirement home regulated under the Retirement Homes Act, 2010 that is a Group C occupancy.
Open OBC Div. B 3.2.6.8. in the code viewer

Show all 23 articles

OBC Div. B 3.2.6.9. Testing
(1)The systems for control of smoke movement and mechanical venting required by Articles 3.2.6.2. and 3.2.6.6. shall be tested to ensure satisfactory operation in accordance with the procedures described in MMAH Supplementary Standard SB-4, "Measures for Fire Safety in High Buildings."
Open OBC Div. B 3.2.6.9. in the code viewer
OBC Div. B 3.2.7.3. Emergency Lighting
(1)Emergency lighting shall be provided to an average level of illumination not less than 10 lx at floor or tread level in
(a)exits,
(b)principal routes providing access to exit in open floor areas and in service rooms,
(c)corridors used by the public,
(d)corridors serving patients' or residents' sleeping rooms in a Group B, Division 2 or 3 occupancy,
(e)reserved
(f)corridors serving classrooms,
(g)underground walkways,
(h)public corridors,
(i)floor areas or parts of thereof where the public may congregate
(i)in Group A, Division 1 occupancies, or
(ii)in Group A, Divisions 2 and 3 occupancies having an occupant load of 60 or more,
(j)floor areas or parts of thereof in day care centres where persons are cared for,
(k)food preparation areas in commercial kitchens,
(l)washrooms with fixtures for public use,
(m)locations where doors are equipped with an electromagnetic lock as described in Clauses 3.4.6.16.(5)(k),
(n)universal washrooms required by Article 3.8.3.12. and universal shower rooms required by Article 3.8.3.13.,
(o)principal routes providing access to exit in a floor area that is not subdivided into rooms or suites of rooms served by corridors in a business and personal services occupancy, a mercantile occupancy or an industrial occupancy, and
(p)internal corridors or aisles serving as principal routes to exits in a business and personal services occupancy, a mercantile occupancy or an industrial occupancy that is subdivided into rooms or suites of rooms, and is not served by a public corridor.
(2)Emergency lighting to provide an average level of illumination of not less than 10 lx at floor or catwalk level shall be included
(a)in a service space referred to in Sentence 3.2.1.1.(8), and
(b)on a shelf and rack storage system, in locations described in Sentence 3.16.1.5.(2).
(3)The minimum value of the illumination required by Sentences (1) and (2) shall not be less than 1 lx.
(4)In addition to the requirements of Sentences (1) to (3), the installation of battery-operated emergency lighting in health care facilities shall conform to the appropriate requirements of CSA Z32, "Electrical safety and essential electrical systems in health care facilities."
Open OBC Div. B 3.2.7.3. in the code viewer
OBC Div. B 3.2.7.4. Emergency Power for Lighting
(1)An emergency power supply shall be
(a)provided to maintain the emergency lighting required by this Subsection from a power source such as batteries or generators that will continue to supply power in the event that the regular power supply to the building is interrupted, and
(b)so designed and installed that upon failure of the regular power it will assume the electrical load automatically for a period of
(i)2 h for a building within the scope of Subsection 3.2.6.,
(ii)1 h for a building of Group B major occupancy classification that is not within the scope of Subsection 3.2.6.,
(iii)(ii.1) 1 h for a building that contains a Group C major occupancy retirement home and that is not within the scope of Subsection 3.2.6.,
(iv)1 h for a building within the scope of Article 3.2.2.51. or 3.2.2.60, and
(v)30 min for a building of any other occupancy. (See Note A-3.2.7.4.(1))
(2)If self-contained emergency lighting units are used, they shall conform to CSA C22.2 No. 141, "Emergency lighting equipment."
Open OBC Div. B 3.2.7.4. in the code viewer
OBC Div. B 3.2.7.8. Emergency Power for Fire Alarm Systems
(1)Fire alarm systems, including those incorporating a voice communication system, shall be provided with an emergency power supply conforming to Sentences (2) to (4).
(2)The emergency power supply required by Sentence (1) shall be supplied from
(a)a generator,
(b)batteries, or
(c)a combination thereof.
(3)The emergency power supply required by Sentence (1) shall be capable of providing
(a)supervisory power for not less than 24 h, and
(b)immediately following that period, emergency power under full load for not less than
(i)2 h for a building within the scope of Subsection 3.2.6.,
(ii)1 h for a building classified as Group B major occupancy that is not within the scope of Subsection 3.2.6.,
(iii)(ii.1) 1 h for a building that contains a Group C major occupancy retirement home and that is not within the scope of Subsection 3.2.6.,
(iv)1 h for a building within the scope of Article 3.2.2.51. or 3.2.2.60.,
(v)5 min for a building not required to be equipped with an annunciator, and
(vi)30 min for any other building. (See Note A-3.2.7.8.(3))
(4)The emergency power supply required by Sentence (1) shall be designed so that, in the event of a failure of the normal power source, there is an immediate automatic transfer to emergency power with no loss of information.
Open OBC Div. B 3.2.7.8. in the code viewer
OBC Div. B 3.2.7.5. Emergency Power Supply Installation
(1)Except as required by Articles 3.2.7.6. and 3.2.7.7., an emergency electrical power supply system shall be installed in conformance with CSA C282, "Emergency electrical power supply for buildings." (See Sentence 3.2.7.8.(1) for emergency electrical power supply for voice communication systems.)
(2)Every emergency power supply shall be equipped with an emergency audible and visual trouble indication.
Open OBC Div. B 3.2.7.5. in the code viewer
OBC Div. B 3.2.7.9. Emergency Power for Building Services
(1)An emergency power supply capable of operating under a full load for not less than 2 h shall be provided by an emergency generator for
(a)every elevator serving storeys above the first storey in a building that is more than 36 m high measured between grade and the floor level of the top storey and every elevator for firefighters in conformance with Sentence (2),
(b)except as provided in Sentence (4), equipment that supplies water for fire suppression as required by Articles 3.2.5.7. and 3.2.5.8. and Sentences 3.2.5.12.(1) and (2) and 3.2.5.18.(1), if the supply depends solely on electrical power supplied to the building,
(c)fans and other electrical equipment that are installed to maintain the air quality specified in Articles 3.2.6.2. and 3.3.3.6.,
(d)fans required for venting by Article 3.2.6.6., and
(e)fans required by Clause 3.2.8.4.(1)(c) and Article 3.2.8.7. in buildings within the scope of Subsection 3.2.6. (See Note A-3.2.7.9.(1))
(2)Except as permitted by Sentence (3), the emergency power supply for elevators required by Clause (1)(a) shall be capable of operating all elevators for firefighters plus one additional elevator simultaneously.
(3)Sentence (2) does not apply if the time to recall all elevators under emergency power supply is not more than 5 min, each from its most remote storey to
(a)the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4 and 3.2.5.5., or
(b)to a transfer lobby.
(4)The emergency power supply required by Clause (1)(b) for the equipment that supplies water for fire suppression need not be provided for sprinkler systems conforming to NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes."
Open OBC Div. B 3.2.7.9. in the code viewer
OBC Div. B 3.2.7.10. Protection of Electrical Conductors
(1)The protection of electrical and emergency conductors referred to in Clauses (a) to (c) shall conform to the requirements stated in Sentences (2) to (11):
(a)electrical conductors located within buildings identified in Article 3.2.6.1. serving
(i)fire alarms,
(ii)emergency lighting, or
(iii)emergency equipment within the scope of Articles 3.2.6.2. to 3.2.6.8.,
(b)emergency conductors serving fire pumps required to be installed under Article 3.2.5.18., and
(c)emergency conductors serving mechanical systems serving
(i)areas of refuge identified in Clause 3.3.3.6.(1)(b), or
(ii)contained use areas referred to in Clauses 3.3.3.7.(4)(a) and (b).
(2)Except as otherwise required by Sentence (3) and permitted by this Article, electrical conductors that are used in conjunction with systems identified in Sentence (1) shall
(a)conform to CAN/ULC-S139, "Standard for Fire Test for Circuit Integrity of Fire-Resistive Power, Instrumentation, Control and Data Cables," including the hose stream application, to provide a circuit integrity rating of not less than 1 h, or (See Note A-3.2.7.10.(2)(a) and (3)(a)) (See also Clause 3.2.6.5.(6)(b))
(b)be located in a service space that is separated from the remainder of the building by a fire separation that has a fire-resistance rating of not less than 1 h.
(3)Electrical conductors identified in Clause (1)(c) shall
(a)conform to CAN/ULC-S139, "Standard for Fire Test for Circuit Integrity of Fire-Resistive Power, Instrumentation, Control and Data Cables," including the hose stream application, to provide a circuit integrity rating of not less than 2 h, or (See Note A-3.2.7.10.(2)(a) and (3)(a))
(b)be located in a service space that is separated from the remainder of the building by a fire separation that has a fire-resistance rating of not less than 2 h.
(4)The service spaces referred to in Clause (2)(b) and (3)(b) shall not contain any combustible materials other than the electrical conductors being protected.
(5)Except as permitted by Sentences (7) and (9), the electrical conductors referred to in Sentence (1) are those that extend from the source of emergency power to
(a)the equipment served, or
(b)the distribution equipment supplying power to the equipment served, if both are in the same room. (See Note A-3.2.7.10.(5)(b))
(6)If a fire alarm transponder or annunciator located in one fire compartment is connected to a central processing unit or another transponder or annunciator located in a different fire compartment, the electrical conductors connecting them shall be protected in accordance with Sentence (2).
(7)Fire alarm system branch circuits within a storey that connect transponders and individual devices need not conform to Sentence (2). (See Note A-3.2.7.10.(7))
(8)Except as permitted in Sentence (9), if a distribution panel supplies power to emergency lighting, the power supply conductors leading up to the distribution panel shall be protected in accordance with Sentence (2).
(9)Conductors leading from a distribution panel referred to in Sentence (8) to emergency lighting units in the same storey need not conform to Sentence (2).
(10)Distribution panels serving emergency lighting units located on other storeys shall be installed in a service room separated from the floor area by a fire separation having a fire-resistance rating of at least 1 h.
(11)Conductors leading from a distribution panel to emergency lighting units located on other storeys shall be protected in accordance with Sentence (2) between the distribution panel and the floor area where the emergency lighting units are located.
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OBC Div. A 1.4.1.2.(1) Interconnected floor space
Interconnected floor space means superimposed floor areas or parts of floor areas in which floor assemblies that are required to be fire separations are penetrated by openings that are not provided with closures.
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OBC Div. B 3.2.8.3. Sprinklers
(1)A building containing an interconnected floor space shall be sprinklered throughout.
(2)Except for large floor openings as defined in NFPA 13, "Standard for the Installation of Sprinkler Systems," closely spaced sprinklers and associated draft stops shall be installed around floor openings in conformance with NFPA 13.
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OBC Div. B 3.2.8.8. Combustible Content Limits
(1)An interconnected floor space shall be designed so that the combustible contents, excluding interior finishes, in those parts of a floor area in which the ceiling is more than 8 m above the floor, are limited to not more than 16 g of combustible material for each cubic metre of volume of the interconnected floor space.
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OBC Div. B 3.2.8.4. Vestibules
(1)An exit opening into an interconnected floor space shall be protected at each opening into the interconnected floor space by a vestibule
(a)with doorways that are not less than 1.8 m apart,
(b)that is separated from the remainder of the floor area by a fire separation that is not required to have a fire-resistance rating, and (See Note A-3.1.8.1.(1)(b))
(c)that is designed to limit the passage of smoke so that the exit stair shaft does not contain more than 1% by volume of contaminated air from the fire floor, assuming an outdoor temperature equal to the January design temperature on a 2.5% basis determined in accordance with MMAH Supplementary Standard SB-1, "Climatic and Seismic Data." (See Note A-3.2.8.4.(1)(c))
(2)An exit opening into an interconnected floor space shall conform to Sentence 3.4.3.2.(6).
(3)If an elevator hoistway opens into an interconnected floor space and into storeys above the interconnected floor space, either the elevator doors opening into the interconnected floor space or the elevator doors opening into the storeys above the interconnected floor space shall be protected by vestibules conforming to Sentence (1).
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OBC Div. B 3.2.8.5. Protected Floor Space
(1)A protected floor space used to satisfy the requirements of Clause 3.4.3.2.(6)(b) shall
(a)be separated from the interconnected floor space by a fire separation having a fire-resistance rating not less than that required for the floor assembly of the storey in which it is located,
(b)have all openings in the vertical fire separation between a protected floor space and the adjacent interconnected floor space protected by vestibules conforming to Sentence 3.2.8.4.(1), and
(c)be designed so that it is not necessary to enter the interconnected floor space to reach an exit.
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OBC Div. B 3.2.8.6. Draft Stops
(1)A draft stop shall be provided at each floor level within an interconnected floor space, immediately adjacent to and surrounding the opening, and shall be not less than 500 mm deep measured from ceiling level down to the underside of the draft stop.
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OBC Div. B 3.2.8.7. Mechanical Exhaust System
(1)A mechanical exhaust system shall be provided to remove air from an interconnected floor space at a rate of 4 air changes per hour. (See Note A-3.2.8.7.(1))
(2)The mechanical exhaust system required by Sentence (1) shall be actuated by a switch located on the storey containing the entrance for firefighter access referred to in Articles 3.2.5.4. and 3.2.5.5. near the annunciator for the fire alarm system.
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OBC Div. B 3.2.9.1. Testing
(1)Where fire protection and life safety systems, and systems with fire protection and life safety functions, are integrated with each other, the systems shall be tested as a whole in accordance with CAN/ULC-S1001, "Standard for Integrated Systems Testing of Fire Protection and Life Safety Systems", to verify that they have been properly integrated. (See Note A-3.2.9.1.(1))
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