High buildings (3.2.6 and SB-4): BCIN Complex Buildings

Last updated October 22, 2026

Values this chapter turns on

top storey floor height that triggers 3.2.6.: 36 m; top storey floor height that triggers 3.2.6.
trigger height for Group B, C or retirement homes: 18 m; trigger height for Group B, C or retirement homes
stair vent area per door, with a 1.8 m² minimum: 0.05 m²; stair vent area per door, with a 1.8 m² minimum
min platform area of the firefighter elevator: 2.2 m²; min platform area of the firefighter elevator

Subsection 3.2.6. is the heart of the Complex Buildings exam. It adds smoke control, firefighter elevators, a central alarm and control facility and voice communication to tall buildings and to buildings whose occupants cannot easily leave. "High building" is not a defined term: Article 3.2.6.1. is the trigger.

Application and limits to smoke movement (SB-4)

OBC Div. B 3.2.6.1. applies the Subsection to a building that meets any one of these tests. Heights are measured from grade to the floor level of the top storey (or of the highest storey of the named occupancy), not to the roof.

Building contains	Trigger
Group A, D, E or F	top storey floor more than 36 m above grade
Group A, D, E or F	more than 18 m, and occupant load above the storey divided by 1.8 times the exit stair width (m) exceeds 300
Group B major occupancy	highest Group B storey more than 18 m above grade
Group B, Division 2 or 3	any floor area, or part of one, above the third storey
Group C major occupancy	highest Group C storey more than 18 m above grade
Retirement home	highest retirement home storey more than 18 m above grade
Encapsulated mass timber (3.2.2.57. or 3.2.2.93.)	highest storey more than 18 m above grade

Note the care trigger: a Group B, Division 2 or 3 floor area on the fourth storey brings in 3.2.6. even if the building is only about 12 m high.

Sprinklered buildings. 3.2.6.2. requires design to Sentences (2) to (6) and SB-4:

Exit stairs serving storeys below the lowest exit level may hold no more than 1% by volume of contaminated air from the fire floor for 2 h, at the SB-1 January 2.5% design temperature.
Each stair serving storeys above the lowest exit level gets a vent to outdoors at or near the bottom. Size it at 0.05 m² per door into the stair, with a 1.8 m² minimum. It opens manually and stays open in a fire.
Smoke from floors below the lowest exit storey must be kept out of upper storeys.
Fans in a system serving more than 2 storeys must be stoppable from a manual switch at the central alarm and control facility. Dwelling unit kitchen and bathroom exhaust fans and smoke venting fans are exempt.
Make-up air to public corridors serving Group C suites generally keeps running on alarm, to hold corridor pressurization.

Unsprinklered buildings must follow SB-4 in full (Sentence (7)). If the building is connected to another building, contaminated air must be kept from moving between them (3.2.6.3.).

What SB-4 adds (SB-4 3.2.6.2.). A stair serving floors below the lowest exit level complies if it has a top vent of about 0.1 m² per storey served, air supply at the bottom of 0.47 m³/s per storey served, and no shared shaft with the upper stair at the exit level. For mechanical pressurization, SB-4 recommends at least 12 Pa. Measure A is deemed to satisfy 3.2.6.2.(2) to (5) (SB-4 equivalent measure).

Practice this topic

Firefighter elevators and emergency operation

3.2.6.4. covers elevators serving storeys above the first storey:

manual emergency recall, with key-operated switches at each elevator lobby on the recall level and at the central alarm and control facility;
in-car emergency service switches in every car;
keys kept at the central facility and in a marked box on a nearby hoistway;
in an unsprinklered building, automatic recall too, set off by lobby smoke detectors on every storey or by the fire alarm system.

3.2.6.5. requires at least one elevator for firefighters:

Item	Requirement
Platform	at least 2.2 m² usable area
Performance	900 kg to the top floor it serves within 1 min, from the firefighter access storey
Protection (unless SB-4 Measure K)	1 h shaft closures keeping interlocks working, or a vestibule with a 45 min fire separation, or a corridor with a 1 h fire separation
Reach	every above-grade floor normally served; at most one change of elevator
Wiring	in a Section 3.6. service space with no other combustibles, or 1 h circuit integrity to CAN/ULC-S139

Venting. 3.2.6.6. requires a way to vent each floor area to outdoors: windows, wall panels, smoke shafts or (if sprinklered) the building exhaust system. Openable vent windows are permanently marked, and hoistways may never be used. SB-4 gives the details (SB-4 3.2.6.6.): vent windows total at least 1% of each storey's exterior wall area, smoke shafts end at least 900 mm above the roof, and in a sprinklered building an air handling system can vent if it achieves 6 air changes per hour on emergency power.

Emergency power. For a 3.2.6. building, emergency lighting runs 2 h (3.2.7.4.) and the fire alarm needs 24 h of supervisory power then 2 h at full load (3.2.7.8.). A generator must run for 2 h the elevators in buildings over 36 m, the firefighter elevators, smoke control fans and venting fans (3.2.7.9.). It must carry all firefighter elevators plus one more at once, unless every elevator can be recalled in 5 min or less. Conductors to fire alarm, emergency lighting and 3.2.6. equipment need 1 h protection (3.2.7.10.).

Practice this topic

Central alarm and control facility and voice communication

3.2.6.7. places the central alarm and control facility on the storey with the firefighter access entrance, where firefighters reach it easily and background noise is considered. Its controls include:

voice messages to all speakers, single floor areas, and exit stairwells;
alert and alarm indication with a silence switch and a "silenced" indicator;
elevator recall indication and two-way talk with every car;
the annunciator, transmission to the fire department, release of vestibule hold-open devices;
selective manual alarm by zone;
control of smoke control, connected building and venting equipment, or a link to a staffed auxiliary control centre;
separate sprinkler waterflow indication, and sprinkler and standpipe supervisory and trouble signals.

A voice communication system is required (3.2.6.8.) when:

the top storey floor is more than 36 m above grade;
a Group B, Division 2 or 3 floor area is above the third storey; or
a retirement home floor area is more than 18 m above grade.

So a Group C tower with its top storey floor 25 m above grade and no retirement home is a 3.2.6. building but needs no voice system. The system itself follows 3.2.4.22.: two-way communication from each floor area, emergency telephones near exit stair shafts, and broadcast audible everywhere except elevator cars. Signals may be silenced for voice messages only after 30 s, or 10 s in a hospital with 24 h supervisory staff. The smoke control and venting systems are tested to SB-4 (3.2.6.9.).

Practice this topic

Interior finish in high buildings

3.1.13.7. adds smoke developed limits to the normal flame-spread rules. Key values from Table 3.1.13.7.:

Location	Wall flame-spread	Wall smoke developed
Exit stairways, their vestibules, 3.4.4.2.(2) lobbies	25	50
Elevator cars	75	450
Elevator vestibules	25	100
Service spaces and service rooms	25	50

Relaxations:

In a sprinklered building the table does not apply, except in a Group B major occupancy and in elevator cars.
Trim in exit stairs, vestibules, lobbies and corridors not within suites: flame-spread 150 and smoke developed 300, if no more than 10% of the wall or ceiling.
Doors in those locations: flame-spread 200 and smoke developed 300, if all doors total no more than 10% of the wall.
Plumbing fixtures: smoke developed 300, with relaxations for sprinklered buildings and Group C rooms.

Practice this topic

Common traps

Measuring to the roof or to the top storey ceiling. 3.2.6.1. measures to the floor level of the top storey.
Thinking a high building needs voice communication automatically. 3.2.6.8. has its own three triggers.
Using 1.8 m² as the vent per door. It is 0.05 m² per door with a 1.8 m² minimum.
Applying the sprinklered relaxation in 3.1.13.7.(2) to a hospital. Group B and elevator cars never get it.

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
Application and limits to smoke movement (SB-4)	Note the care trigger: a Group B, Division 2 or 3 floor area on the fourth storey brings in 3.2.6. even if the building is only about 12 m high.
Central alarm and control facility and voice communication	So a Group C tower with its top storey floor 25 m above grade and no retirement home is a 3.2.6. building but needs no voice system.

Application and limits to smoke movement (SB-4)
Note the care trigger: a Group B, Division 2 or 3 floor area on the fourth storey brings in 3.2.6. even if the building is only about 12 m high.
Central alarm and control facility and voice communication
So a Group C tower with its top storey floor 25 m above grade and no retirement home is a 3.2.6. building but needs no voice system.

Usual exam traps

Measuring to the roof or to the top storey ceiling. 3.2.6.1. measures to the floor level of the top storey.
Thinking a high building needs voice communication automatically. 3.2.6.8. has its own three triggers.
Using 1.8 m² as the vent per door. It is 0.05 m² per door with a 1.8 m² minimum.
Applying the sprinklered relaxation in 3.1.13.7.(2) to a hospital. Group B and elevator cars never get it.

Practice this chapter

Questions on High buildings (3.2.6 and SB-4), in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

Practice this chapter Free Complex Buildings quiz

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 Div. B 3.2.6.3. Connected Buildings
(1)If a building described in Article 3.2.6.1. is connected to any other building, measures shall be taken to limit movement of contaminated air from one building into another during a fire. (See Note A-3.2.6.3.(1))
Open OBC Div. B 3.2.6.3. in the code viewer
OBC SB-4 3.2.6.2. (2) Stairway Protection Below Lowest Exit Level
These provisions are intended to apply to common building designs. Where a stair serving floors below the lowest exit level is open to the exterior or the stair serves only one storey below grade, compliance with the following provisions may not be necessary.
A stairway serving floors below the lowest exit level is considered to comply with the intent of Sentence 3.2.6.2.(2) of Division B if all of the following conditions are satisfied.
(1)The stairway has a vent or door to the outdoors at or near the top of the stair shaft that has an openable area of not less than 0.1 m² for each storey served by the stairway, less 0.01 m² for each weatherstripped door and 0.02 m² for each door that is not weatherstripped opening into the stairway.
(2)The stairway is enclosed in a shaft that
(a)does not pass through the floor above the lowest exit level and is separate from a shaft that contains a stairway serving upper storeys, or
(b)contains a stairway serving upper storeys, but is separated from that stairway at the lowest exit level by a fire separation having a fire resistance rating not less than that required for the shaft enclosure.
(3)The stairway is provided with equipment capable of maintaining a flow of air introduced at or near the bottom of the stair shaft, at a rate equal to 0.47 m³/s for each storey served by the stairway.
Open OBC SB-4 3.2.6.2. in the code viewer
OBC SB-4 Equivalent Measure
Where a building is designed in accordance with Measure A as described in Sections 2 and 3 of this Supplementary Standard, the building shall be deemed to comply with Sentences 3.2.6.2.(2) to (5) of Division B of the Building Code.
Open OBC SB-4 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

Show all 19 articles

OBC SB-4 3.2.6.6. (1) Venting to Aid Firefighting
(1)The requirements of Sentence 3.2.6.6.(1) of Division B and of Measures H or I are met by incorporating in a floor area windows or wall panels as described in Sentence (2), by smoke shafts as described in Sentences (3) to (7) or by the use of building exhaust systems as described in Sentence (8).
(2)Where windows or wall panels are used for venting as required in Sentence (1), they must
(a)be uniformly distributed along the exterior wall of each storey,
(b)have a total area of not less than one percent of the exterior wall area of each storey,
(c)be readily openable from the interior without the use of wrenches or keys,
(d)be readily identified from the interior, and from the exterior where they are accessible to firefighters, and
(e)be designed so that when opened they will not endanger persons outside the building during a fire.
(3)Where one or more smoke shafts or vertical service spaces are used for venting to meet the requirements of Sentence (1), they must
(a)have an opening or openings into each storey with an aggregate area not less than that obtained from Table 1 for the height of the shaft, the area of the largest floor area served by the smoke shaft and the leakage characteristics of the shaft wall and closures obtained from Tables 2 and 3,
(b)have an aggregate unobstructed cross-sectional area equal to that provided in Clause (a), and
(c)be designed to comply with the requirements of Sentence (4).
(4)Each smoke shaft or vertical service space described in Sentence (3) must
(a)be separated from the remainder of the building by a fire separation that has a fire-resistance rating at least equal to that required for the floor assembly through which it passes, or be designed as a chimney conforming to Part 6 of Division B, except that flue liners need not be provided,
(b)have an opening to the outdoors at the top that has an area not less than the cross-sectional area of the shaft which may be protected from the weather,
(c)terminate not less than 900 mm above the roof surface where it penetrates the roof, and
(d)contain no combustible material, fuel lines or services that are required for use in an emergency.
(5)Each opening required by Clause (3)(a) must be located so that the top of the opening is not more than 250 mm below the ceiling, except that the opening may be above the ceiling if the ceiling freely allows passage of air and the opening into the smoke shaft is provided with a closure that
(a)has a fire-protection rating conforming to Sentence 3.1.8.4.(2) of Division B, except that the temperature on the unexposed face of the closure is not more than 250°C after 30 min during the fire test and there is no combustible material within the distances described in Table 4, and except that paint or tightly-adhering paper covering not more than 1 mm thick shall be exempted from these requirements when applied to a noncombustible backing,
(b)can be opened from a remote location such as a stair shaft, the storey immediately below or the central alarm and control facility, and
(c)must not open automatically on any floor, other than the fire floor, when smoke or hot gases pass through the shaft.
(6)Closures for openings described in Clause 4(b) are to be openable from the outside and will open automatically on a signal from a smoke detector in the shaft, by operation of the fire alarm system and when a closure required in Sentence (5) opens.
(7)A smoke shaft opening referred to in Sentence (2) or (3) that is less than 1,070 mm above the floor must be protected by guards in conformance with Article 3.3.1.18. of Division B.
(8)In a sprinklered building, the air handling system may be used for smoke venting provided
(a)the system can maintain an exhaust to the outdoors at the rate of six air changes per hour from any floor area, and
(b)emergency power to the fans required by (a) is provided as described in Article 3.2.7.9. of Division B.
(9)Where a closure is required by Sentence (5), the leakage area between closure components and between damper and frame must be not more than 3 percent of the openable area of the damper.
Open OBC SB-4 3.2.6.6. 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 3.2.7.9. 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.
Open OBC Div. B 3.2.7.10. 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
OBC Div. B 3.2.4.22. Two-Way Voice Communication Systems
(1)A voice communication system required by Subsection 3.2.6., Clause 3.3.2.4.(14)(f) or Sentence 3.3.4.11.(12) shall
(a)consist of a two-way means of communication with the central alarm and control facility and to the mechanical control centre from each floor area, and
(b)be capable of broadcasting pre-recorded, synthesized or live messages from the central alarm and control facility that are audible and intelligible in all parts of the building, except elevator cars. (See Note A-3.2.4.22.(1)(b))
(2)The voice communication system referred to in Sentence (1) shall include a means to silence the alarm signal in a single-stage fire alarm system while voice instructions are being transmitted, but only after the alarm signal has initially sounded for not less than 30 s.
(3)The voice communication system referred to in Sentence (1) shall include a means to silence the alert signal and the alarm signal in a 2-stage fire alarm system while voice instructions are being transmitted, but only after the alert signal has initially sounded for not less than
(a)10 s in hospitals that have supervisory personnel on duty for twenty-four hours each day, or
(b)30 s for all other occupancies.
(4)The voice communication system referred to in Clause (1)(b) shall be designed so that the alarm signal in a 2-stage fire alarm system can be selectively transmitted to any zone or zones while maintaining an alert signal or selectively transmitting voice instructions to any other zone or zones in the building.
(5)The 2-way communication system referred to in Clause (1)(a) shall be installed so that emergency telephones are located in each floor area near exit stair shafts.
(6)Visible signal devices required by Sentence 3.2.4.19.(1) shall continue to emit a visible signal while voice instructions are being transmitted.
(7)Where the facility is not equipped with staff trained to provide instructions over the loudspeakers, a pre-recorded message shall be provided.
Open OBC Div. B 3.2.4.22. in the code viewer
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 3.1.13.7. High Buildings
(1)Except as permitted by Sentences (2) to (4), the interior wall, ceiling and floor finishes in a building regulated by the provisions of Subsection 3.2.6. shall conform to the flame-spread rating requirements in Articles 3.1.13.2. to 3.1.13.6. and 3.1.13.11. and to the flame-spread rating and smoke developed classification values in Table 3.1.13.7.
(2)Except for a building of Group B major occupancy and elevator cars, the flame-spread rating and smoke developed classification of interior wall, floor and ceiling finishes need not conform to the values in Table 3.1.13.7., provided the building is sprinklered.
(3)Trim and millwork in an exit stairway, a vestibule to an exit stairway, a lobby described in Sentence 3.4.4.2.(2), or a corridor not within a suite need not conform to the flame-spread rating and smoke developed classification requirements of Sentence (1), provided they have
(a)a flame-spread rating not more than 150,
(b)a smoke developed classification not more than 300, and
(c)an aggregate area not more than 10% of the area of the wall or ceiling on which they occur.
(4)A door serving an exit stairway, a vestibule to an exit stairway, a lobby described in Sentence 3.4.4.2.(2), or a corridor not within a suite need not conform to the flame-spread rating and smoke developed classification requirements of Sentence (1) provided
(a)it has a flame-spread rating not more than 200,
(b)it has a smoke developed classification not more than 300, and
(c)the aggregate area of all doors is not more than 10% of the area of the wall in which they are located.
(5)Except as permitted in Sentences (6) to (8), plumbing fixtures in a building regulated by the provisions of Subsection 3.2.6. shall have a smoke developed classification not more than 300.
(6)A plumbing fixture that is not located in a Group B occupancy need not comply with Sentence (5) if the building is sprinklered throughout.
(7)A plumbing fixture may have a smoke developed classification more than 300 but not more than 500 if,
(a)it is in a room where the wall surfaces have a smoke developed classification not more than 200, and
(b)it is located in,
(i)a Group C occupancy, or
(ii)a Group B occupancy and the building is sprinklered throughout.
(8)A therapeutic bathing system in a Group B occupancy need not comply with Sentence (5) if the room in which it is located.
(a)does not open directly into patients' or residents' sleeping rooms, and
(b)is sprinklered.
Open OBC Div. B 3.1.13.7. in the code viewer
OBC Div. B Table 3.1.13.7. Flame-Spread Rating and Smoke Developed Classification in High Buildings
Table 3.1.13.7. — Flame-Spread Rating and Smoke Developed Classification in High Buildings Forming Part of Sentences 3.1.13.7.(1) and (2) Location or Element | Maximum Flame-Spread Rating: Wall Surface | Maximum Flame-Spread Rating: Ceiling Surface[1] | Maximum Flame-Spread Rating: Floor Surface | Maximum Smoke Developed Classification: Wall Surface | Maximum Smoke Developed Classification: Ceiling Surface[1] | Maximum Smoke Developed Classification: Floor Surface Exit stairways, vestibules to exit stairs and lobbies described in Sentence 3.4.4.2.(2) | 25 | 25 | 25 | 50 | 50 | 50 Corridors not within suites | [2] | [2] | 300 | 100 | 50 | 500 Elevator cars | 75 | 75 | 300 | 450 | 450 | 450 Elevator vestibules | 25 | 25 | 300 | 100 | 100 | 300 Service spaces and service rooms | 25 | 25 | 25 | 50 | 50 | 50 Other locations and elements | [2] | [2] | No limit | 300 | 50 | No limit Notes to Table 3.1.13.7.: (1) See Sentence 3.1.13.4.(1) for lighting elements. (2) Other requirements of this Part apply.
Open OBC Div. B Table 3.1.13.7. in the code viewer