Fire alarm and detection systems (3.2.4) (Fire Protection)

Last updated October 22, 2026

Values this chapter turns on

total occupant load that triggers a fire alarm: 300 persons; total occupant load that triggers a fire alarm
unacknowledged alert before a 2-stage alarm: 5 min; unacknowledged alert before a 2-stage alarm
max alarm zone, unsprinklered buildings: 2,000 m²; max alarm zone, unsprinklered buildings
minimum smoke alarm strobe in sleeping rooms: 175 cd; minimum smoke alarm strobe in sleeping rooms

Subsection 3.2.4. is long, but it follows a logical order: when a fire alarm system is needed, how it is laid out, what it must supervise and detect, how loud and visible the signals are, and when smoke alarms are needed in suites. The design and installation detail sits in CAN/ULC-S524, which candidates do not have, so the exam asks about the code's triggers and numbers, and which standard applies.

Where required and system types

Sprinklered buildings. Any building with a sprinkler system needs a fire alarm system, unless the sprinklers are to NFPA 13D or there are fewer than 9 sprinklers fed under 3.2.5.12.(4) (OBC Div. B 3.2.4.1.).

Unsprinklered buildings. A fire alarm is needed if the building contains any of the items in Sentence (4). Selected triggers:

Trigger (unsprinklered building)	Threshold
Storeys, including those below the first storey	more than 3
Total occupant load	more than 300
Occupant load above or below the first storey	more than 150
School, college or child care	more than 40
Licensed beverage establishment or restaurant	more than 150
F2 or F3 above or below the first storey	more than 75
F1	more than 25
Residential sleeping accommodation	more than 10 persons
Care, or care and treatment	more than 10 persons
Contained use area or impeded egress zone	any

Relaxations: a residential building where not more than 4 suites share a common means of egress, or each suite has direct access to an exterior exit facility; a hotel up to 3 storeys with exterior exit access from each suite (3.2.4.1.).

One system, everywhere. If a fire alarm is required anywhere, it goes throughout the building and one system serves all occupancies (3.2.4.2.). Openings through a firewall (other than for pipes and wiring) join the two sides for alarm purposes, and remember from Division A that a firewall never splits the alarm count. A portion up to 3 storeys cut off by a 1 h vertical fire separation with no openings may be treated separately.

Types (3.2.4.3.): single-stage in F1 and in elementary and secondary schools; 2-stage in Group B (B3 up to 3 storeys may use either); either type elsewhere. A single-stage system sounds the alarm everywhere at once. A 2-stage system sounds an alert first and goes to alarm automatically if the alert is not acknowledged within 5 min (not in B2) (3.2.4.4.). Installation is to CAN/ULC-S524 and verification to CAN/ULC-S537 (3.2.4.5.).

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Annunciation, supervision and detectors

An annunciator goes near the entrance facing the street or access route (3.2.4.8.). Zones: not more than 2,000 m² in unsprinklered buildings; in sprinklered buildings one storey and not over the NFPA 13 system area. It can be omitted for small unsprinklered buildings (up to 2,000 m² aggregate and 3 storeys), with a trouble signal at the main entrance instead.

Electrical supervision covers the fire alarm itself and sprinkler conditions such as valve movement, dry pipe air loss, fire pump power loss and low temperature in dry pipe enclosures (3.2.4.9.). Standpipe water supply valves need supervised switches where there is an annunciator, except hose valves. Fire pumps are supervised as NFPA 20 stipulates.

Fire detectors are needed in unsprinklered buildings with a required alarm in storage rooms, service rooms, janitors' rooms, hazardous substance rooms, hoistways, residential laundry rooms and hazardous school rooms (3.2.4.10.).

Smoke detectors are needed wherever a fire alarm is installed in: Group B sleeping rooms and their corridors, contained use areas, A1 corridors, Group C public corridors, exit stair shafts, near 3.2.8.6. draft stops, elevator machine rooms (which then recall the elevators), and school classroom corridors (3.2.4.11.). Air-handling systems serving more than one storey or suite shut down or prevent smoke circulation on a duct detector signal (3.2.4.12.).

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Signals, audibility and voice communication

Item	Value
Auto-silence not before	5 min (no annunciator) or 20 min (3.2.4.6.)
Minimum level in floor area	10 dBA over ambient and at least 65 dBA (3.2.4.18.)
Residential sleeping room, doors closed	at least 75 dBA
Maximum at 3 m from device	110 dBA
Visible signals where ambient noise exceeds	87 dBA (3.2.4.19.)
One-way voice system	2-stage system with occupant load over 1,000 (3.2.4.23.)

Alarm signals use the temporal pattern of ISO 8201, and alert signals must sound clearly different. Dwelling unit devices may be silenced manually for not more than 10 min. Visible signals are also needed in public corridors of A to E occupancies, in at least 10% of hotel suites, and in apartment living spaces. Two-way voice systems for high buildings let staff silence the alarm for voice messages only after it has sounded for at least 30 s in most occupancies (10 s for the alert signal in hospitals with round-the-clock supervisory staff) (3.2.4.22.).

Know the definitions: an alarm signal tells occupants of a fire emergency; an alert signal advises designated persons.

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Smoke alarms

Smoke alarms to CAN/ULC-S531 go in every dwelling unit and in sleeping rooms outside dwelling units (except care, care and treatment or detention occupancies that need a fire alarm system) (OBC Div. B 3.2.4.20.):

at least one on each storey and mezzanine;
one in each sleeping room and one in the hallway (or between the bedrooms and the rest of the storey);
on or near the ceiling, interconnected within the dwelling unit;
hard-wired with no disconnect switch, with battery back-up for 7 days then 4 minutes of alarm;
a visual component, at least 175 cd in sleeping rooms;
a hush feature of not more than 10 min.

Residential suites may use system smoke detectors instead of smoke alarms if they sound 75 to 110 dBA within the suite and are installed and verified to S524 and S537. Where no fire alarm is installed or required, a residential fire warning system to CAN/ULC-S540 may replace the smoke alarms (3.2.4.21.).

Common traps: treating a firewall as splitting the alarm requirement; confusing the 5 min alert-to-alarm delay with the 5 min silencing limit; mixing S524 (installation), S537 (verification), S531 (smoke alarms) and S553 (smoke alarm installation).

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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
Where required and system types	Relaxations: a residential building where not more than 4 suites share a common means of egress, or each suite has direct access to an exterior exit facility; a hotel up to 3…
Annunciation, supervision and detectors	An annunciator goes near the entrance facing the street or access route.
Signals, audibility and voice communication	Alarm signals use the temporal pattern of ISO 8201, and alert signals must sound clearly different.
Smoke alarms	Smoke alarms to CAN/ULC-S531 go in every dwelling unit and in sleeping rooms outside dwelling units (except care, care and treatment or detention occupancies that need a fire…

Where required and system types
Relaxations: a residential building where not more than 4 suites share a common means of egress, or each suite has direct access to an exterior exit facility; a hotel up to 3…
Annunciation, supervision and detectors
An annunciator goes near the entrance facing the street or access route.
Signals, audibility and voice communication
Alarm signals use the temporal pattern of ISO 8201, and alert signals must sound clearly different.
Smoke alarms
Smoke alarms to CAN/ULC-S531 go in every dwelling unit and in sleeping rooms outside dwelling units (except care, care and treatment or detention occupancies that need a fire…

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Questions on Fire alarm and detection systems (3.2.4), 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 3.2.4.1. Determination of Requirement for a Fire Alarm System
(1)Except as permitted in Sentences (2) and (3), a fire alarm system shall be installed in buildings in which an automatic sprinkler system is installed.
(2)Buildings in which a sprinkler system is installed in accordance with NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes," need not comply with Sentence (1).
(3)Buildings that contain fewer than 9 sprinklers conforming to Sentence 3.2.5.12.(4) need not comply with Sentence (1).
(4)Except as permitted by Sentences (5), (6) and 3.2.4.2.(4), a fire alarm system shall be installed in a building that is not sprinklered throughout and that contains
(a)a contained use area,
(b)an impeded egress zone,
(c)more than 3 storeys, including storeys below the first storey,
(d)a total occupant load more than 300, other than in open air seating areas,
(e)an occupant load more than 150 above or below the first storey, other than in open air seating areas,
(f)a school, college or child care facility, including a day care facility, with an occupant load more than 40,
(g)a licensed beverage establishment or a licenced restaurant, with an occupant load more than 150,
(h)a low-hazard industrial occupancy with an occupant load more than 75 above or below the first storey,
(i)a medium-hazard industrial occupancy with an occupant load more than 75 above or below the first storey,
(j)a residential occupancy with sleeping accommodation for more than 10 persons,
(k)a high-hazard industrial occupancy with an occupant load more than 25,
(l)an occupant load more than 300 below an open air seating area,
(m)a care and treatment occupancy for more than 10 persons receiving care or treatment, or
(n)a care occupancy for more than 10 persons receiving care.
(4.1)A fire alarm system is not required in a hotel 3 storeys or less in building height provided each suite has direct access to an exterior exit facility leading to ground level.
(5)A fire alarm system is not required in a residential occupancy that is not sprinklered, where
(a)not more than 4 suites share a common means of egress, or
(b)each suite has direct access to an exterior exit facility leading to ground level.
(6)A fire alarm system is not required in a storage garage conforming to Article 3.2.2.92. that is contained in a building that is not sprinklered provided there are no other occupancies in the building.
Open OBC Div. B 3.2.4.1. in the code viewer
OBC Div. B 3.2.4.2. Continuity of Fire Alarm System
(1)Except as permitted by Sentence (6), if there are openings through a firewall, other than those for piping, tubing, wiring and totally enclosed noncombustible raceways, the requirements in this Subsection shall apply to the floor areas on both sides of the firewall as if they were in the same building.
(2)Except as permitted by Sentence (4), if a building contains more than one major occupancy and a fire alarm system is required, a single system shall serve all occupancies.
(3)Except as permitted by Sentence (4), if a fire alarm system is required in any portion of a building, it shall be installed throughout the building.
(4)Except as required by Sentence (5), the requirements in this Subsection are permitted to be applied to each portion of a building not more than 3 storeys in building height, in which a vertical fire separation having a fire-resistance rating not less than 1 h separates the portion from the remainder of the building as if it were a separate building, provided there are no openings through the fire separation, other than those for piping, tubing, wiring and totally enclosed noncombustible raceways.
(5)The permission in Sentence (4) to consider separated portions of a building as separate buildings does not apply to service rooms and storage rooms.
(6)Buildings interconnected by walkways permitted in Articles 3.2.3.19. and 3.2.3.20. or by vestibules provided in conformance with Article 3.2.6.3. shall be treated as separate buildings for the purpose of fire alarm installation required by this Subsection.
Open OBC Div. B 3.2.4.2. in the code viewer
OBC Div. B 3.2.4.3. Types of Fire Alarm Systems
(1)A fire alarm system shall be
(a)a single-stage system in a Group F, Division 1 occupancy,
(b)except as permitted in Clause (c), a 2-stage system in a Group B occupancy,
(c)a single- or 2-stage system in a Group B, Division 3 occupancy where the building is 3 storeys or less in building height,
(d)a single-stage system in elementary and secondary schools, except for a special needs facility, and
(e)a single- or 2-stage system in all other cases.
Open OBC Div. B 3.2.4.3. in the code viewer
OBC Div. B 3.2.4.4. Description of Fire Alarm Systems
(1)A single-stage fire alarm system shall, upon the operation of any manual station, waterflow detecting device, or fire detector, cause an alarm signal to sound on all audible signal devices in the system. (See Note A-3.2.4.4.(1))
(2)A 2-stage fire alarm system shall
(a)cause an alert signal to sound upon the operation of any manual station, waterflow detecting device, or fire detector,
(b)except for a Group B, Division 2 occupancy, automatically cause an alarm signal to sound if the alert signal is not acknowledged within 5 min of its initiation,
(c)have manual stations, each of which is equipped so that the use of a key or other similar device causes an alarm signal to sound that continues to sound upon removal of the key or similar device from the manual station, and (See Note A-3.2.4.4.(2)(c))
(d)in a building containing a hotel,
(i)cause an alarm signal to sound in the initiating fire zone in the hotel, and
(ii)cause an alert signal to sound throughout the hotel and such parts of the building as is necessary to alert hotel staff. (See Note A-3.2.4.4.(2))
(3)A 2-stage fire alarm system is permitted to be zone coded so that, upon the operation of any manual station, waterflow detecting device, or fire detector,
(a)a coded alert signal is sounded indicating the zone of alarm initiation,
(b)the coded alert signal is repeated in its entirety not less than 4 times, and
(c)a continuous alert signal is sounded upon completion of the coded signals referred to in Clause (b) and Sentence (4).
(4)If a second manual station, waterflow detecting device, or fire detector is operated in a fire alarm system with zone coding as permitted by Sentence (3), in a zone other than that for which the first alert signal was sounded, the coded alert signal for the first zone shall be completed before the coded alert signal for the second zone is repeated not less than 4 times.
Open OBC Div. B 3.2.4.4. in the code viewer
OBC Div. B 3.2.4.5. Installation and Verification of Fire Alarm Systems
(1)Fire alarm systems, including those with voice communication capability where provided, shall be installed in conformance with CAN/ULC-S524, "Standard for Installation of Fire Alarm Systems."
(2)Fire alarm systems shall be verified in conformance with CAN/ULC-S537, "Verification of Fire Alarm Systems," to ensure satisfactory operation.
Open OBC Div. B 3.2.4.5. in the code viewer
OBC Div. B 3.2.4.8. Annunciator and Zone Indication
(1)Except as permitted by Sentences (3) to (5), an annunciator shall be installed in close proximity to a building entrance that faces a street or an access route for fire department vehicles that complies with Sentence 3.2.5.5.(1).
(2)Except as permitted by Sentence (6), the annunciator required by Sentence (1) shall have separate zone indication of the actuation of the alarm initiating devices in each
(a)floor area so that the area of coverage for each zone in a building that is not sprinklered is not more than 2,000 m²,
(b)floor area so that the area of coverage for each zone is neither
(i)more than one storey, nor
(ii)more than the system area limits as specified in NFPA 13, "Standard for the Installation of Sprinkler Systems,"
(c)shaft required to be equipped with fire detectors,
(d)air-handling system required to be equipped with smoke detectors,
(e)fire extinguishing system required by NFPA 96, "Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations,"
(f)contained use area,
(g)impeded egress zone, and
(h)fire compartment required by Sentence 3.3.3.5.(2) or Sentence 3.3.4.11.(2).(See Note A-3.2.4.8.(2))
(3)An annunciator need not be provided for a fire alarm system if not more than one zone indicator is required in Sentence (2).
(4)If an annunciator is not installed as part of a fire alarm system in conformance with Sentence (1), a visible and audible trouble signal device shall be provided inside the main entrance of the building.
(5)The requirements in Sentence (1) are waived in a building
(a)in which an automatic sprinkler system is not installed,
(b)that has an aggregate area for all storeys of not more than 2,000 m², and
(c)that is not more than 3 storeys in building height.
(6)The area limits of Clause (2)(a) are waived for an interior undivided open space used as an arena, a rink or a swimming pool provided that other spaces in the building that are separated from the open space are individually zoned in accordance with the requirements of Sentence (2).
(7)A fire alarm control unit installed in close proximity to a building entrance that faces a street or an access route for fire department vehicles that complies with Sentence 3.2.5.5.(1), is deemed to satisfy the requirement for an annunciator provided all indicators required for an annunciator or trouble signal device are included on the control unit. (See Note A-3.2.4.8.(7))
(8)In a building containing a hotel in which a trouble signal sounding device has a silencing switch, a trouble light shall be installed in
(a)the main reception area serving the hotel, or
(b)another continually-supervised location.
(9)In a long-term care home, a remote audiovisual fire alarm trouble signal shall be located at the main nursing station.
Open OBC Div. B 3.2.4.8. in the code viewer
OBC Div. B 3.2.4.9. Electrical Supervision
(1)Electrical supervision shall be provided for a fire alarm system.
(2)If a fire alarm system in a building is required to have an annunciator by Sentence 3.2.4.8.(1), except for hose valves, all valves controlling water supplies in a standpipe system, shall be equipped with an electrically supervised switch for transmitting a trouble signal to the annunciator in the event of movement of the valve handle.
(3)An automatic sprinkler system shall be electrically supervised to indicate a supervisory signal on the building fire alarm system annunciator for each of the following:
(a)movement of a valve handle that controls the supply of water to sprinklers,
(b)loss of excess water pressure required to prevent false alarms in a wet pipe system,
(c)loss of air pressure in a dry pipe system,
(d)loss of air pressure in a pressure tank,
(e)a significant change in water level in any water storage container used for firefighting purposes,
(f)loss of power to any automatically starting fire pump, and (See Note A-3.2.4.9.(3)(f))
(g)a temperature approaching the freezing point in any dry pipe valve enclosure or water storage container used for firefighting purposes.
(4)A fire pump shall be electrically supervised as stipulated in NFPA 20, "Standard for the Installation of Stationary Pumps for Fire Protection."
(5)Electrical supervision shall be provided to indicate, on the fire alarm system annunciator, a loss of power to a heat tracing cable that is installed to heat
(a)a standpipe riser,
(b)a sprinkler line as part of a fire suppression system, or
(c)an exit or means of egress to keep it free of ice and snow.
(6)Indication of a supervisory signal in accordance with Sentences (3) and (5) shall be transmitted to the fire department in conformance with Sentence 3.2.4.7.(4).
Open OBC Div. B 3.2.4.9. in the code viewer
OBC Div. B 3.2.4.10. Fire Detectors
(1)Fire detectors required by this Code shall be connected to the fire alarm system.
(2)Except as permitted by Sentence (3), if a fire alarm system is required in a building that is not sprinklered, fire detectors shall be installed in the following spaces:
(a)storage rooms not within dwelling units,
(b)service rooms not within dwelling units,
(c)janitors' rooms,
(d)rooms in which hazardous substances are to be used or stored, (See Note A-3.3.1.2.(1)),
(e)elevator hoistways or dumbwaiter shafts,
(f)laundry rooms in buildings of residential occupancy, but not those within dwelling units, and
(g)hazardous classrooms and change rooms in elementary or secondary schools.
(3)Fire detectors required by Sentence (2) need not be provided within floor areas that are sprinklered.
(4)Fire detectors required by Sentence (2) shall be installed in elevator hoistways and dumbwaiter shafts where a sprinkler system is not installed within the hoistway or shaft.
Open OBC Div. B 3.2.4.10. in the code viewer

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OBC Div. B 3.2.4.11. Smoke and Heat Detectors
(1)If a fire alarm system is installed, smoke detectors shall be installed in
(a)each sleeping room and each corridor serving as part of a means of egress from sleeping rooms in portions of a building classified as Group B major occupancy,
(b)each room in a contained use area and corridors serving those rooms,
(c)each corridor in portions of a building classified as Group A, Division 1 major occupancy,
(d)each public corridor in portions of a building classified as Group C major occupancy,
(e)each exit stair shaft, other than those serving only a Group A, Division 4 major occupancy or an open storage garage.
(f)the vicinity of draft stops required by Article 3.2.8.6.,
(g)each elevator machine room, and
(h)each corridor serving classrooms in elementary and secondary schools.(See Note A-3.2.4.11.(1))
(2)In a floor area containing a hotel, where a fire alarm system is installed and the floor area is not sprinklered, heat detectors shall be installed in every room in a suite and in every room not located in a suite other than washrooms within a suite, saunas, refrigerated areas and swimming pools.
(3)Smoke detectors required in sleeping rooms of a care, care and treatment or detention occupancy shall, upon actuation, provide an audible and visible signal to staff serving those rooms so that the room or location containing the smoke detector can be easily identified. (See Note A-3.2.4.11.(3))
(4)Smoke detectors required in Clause (1)(g) shall, upon actuation, recall the elevators served by the elevator machine room in which the smoke detector is installed.
(5)Except as permitted in Sentences (6) and (7), smoke detectors installed in buildings required to be equipped with a fire alarm system shall be located near the entrance to walkways described in Articles 3.2.3.19. and 3.2.3.20. or vestibules provided in conformance with Article 3.2.6.3.
(6)Smoke detectors installed at the entrance to the walkways in conformance with Article 3.1.8.14. shall be deemed to meet the requirements of Sentence (5).
(7)Smoke detectors required by Sentence (5) may be replaced with fire detectors in Group F occupancies where the smoke detectors may be subjected to false alarms due to the activities within the building.
Open OBC Div. B 3.2.4.11. in the code viewer
OBC Div. B 3.2.4.12. Prevention of Smoke Circulation
(1)If a fire alarm system is installed, an air-handling system shall be designed to prevent the circulation of smoke upon a signal from a duct-type smoke detector if the air handling system
(a)serves more than one storey,
(b)serves more than one suite in a storey,
(c)serves more than one fire compartment required by Sentence 3.3.3.5.(2) or Sentence 3.3.4.11.(2), or
(d)is not provided with fire dampers as permitted by Sentence 3.1.8.8.(4).
Open OBC Div. B 3.2.4.12. in the code viewer
OBC Div. B 3.2.4.6. Silencing of Alarm Signals
(1)Except as permitted by Sentence (3), a fire alarm system shall be designed so that when an alarm signal is actuated, it cannot be silenced automatically before a period of time has elapsed that is not less than
(a)5 min for a building not required to be equipped with an annunciator, and
(b)20 min for any other building.
(2)Except as permitted by Sentences 3.2.4.18.(8) and Sentences 3.2.4.22.(2) and (3), a fire alarm system shall not incorporate manual silencing switches other than those installed inside the fire alarm control unit. (See Note A-3.2.4.6.(2))
(3)Except as provided by Clause 3.2.4.22.(3)(a), in a care and treatment occupancy an alert signal is permitted to be silenced automatically after 1 min.
Open OBC Div. B 3.2.4.6. in the code viewer
OBC Div. B 3.2.4.18. Audibility of Alarm Systems
(1)Except as permitted by Sentence 3.2.4.19.(2) and except as required by Clause 3.2.4.4.(2)(d), audible signal devices forming part of a fire alarm system shall be installed in a building so that
(a)alarm signals are clearly audible throughout the floor area, and
(b)alert signals are clearly audible in continuously staffed locations, and where there are no continuously staffed locations, throughout the floor area. (See Note A-3.2.4.18.(1))
(2)The sound pattern of an alarm signal shall conform to the temporal pattern defined in Clause 4.2 of ISO 8201, "Acoustics Audible emergency evacuation signal." (See Note A-3.2.4.18.(2))
(3)The sound patterns of alert signals shall be significantly different from the temporal patterns of alarm signals. (See Note A-3.2.4.18.(3))
(4)In all normally occupied spaces, the fire alarm signal sound pressure level
(a)shall be not more than 110 dBA when measured at a distance of 3 m from the device, or
(b)is permitted to be more than 100 dBA provided the sound pressure level measured 2,000 mm above floor level is not more than 100 dBA. (See Note A-3.2.4.18.(4))
(5)The sound pressure level in a sleeping room from a fire alarm audible signal device shall be not less than 75 dBA in a building of residential occupancy when any intervening doors between the device and the sleeping room are closed. (See Note A-3.2.4.18.(5))
(6)Audible signal devices in sleeping rooms in a building of residential or care occupancy shall emit a low frequency signal. (See Note A-3.2.4.18.(6))
(7)Except as required by Sentence (5), the sound pressure level from a fire alarm system's audible signal device within a floor area shall be not less than 10 dBA above the ambient noise level and not less than 65 dBA, when any intervening doors between the device and the rest of the floor area are closed.
(8)Except as permitted by Sentence (12), audible signal devices located within a dwelling unit shall include a means for them to be manually silenced for a period of not more than 10 min, after which time the devices shall restore themselves to normal operation. (See Note A-3.2.4.18.(8))
(9)Audible signal devices within a dwelling unit or a suite of residential occupancy shall be connected to the fire alarm system
(a)in a manner such that a single open circuit at one device will not impair the operation of other audible signal devices on that same circuit that serve the other dwelling units or suites of residential occupancy, or
(b)on separate signal circuits that are not connected to the devices in any other dwelling unit, public corridor or suite of residential occupancy. (See Note A-3.2.4.18.(9) and (10))
(10)In a building or part thereof classified as a residential occupancy,
(a)separate circuits shall be provided for audible signal devices on each floor area, and
(b)audible signal devices within dwelling units or suites of residential occupancy shall be wired on separate signal circuits from those not within suites of residential occupancy or dwelling units. (See Note A-3.2.4.18.(9) and (10))
(11)Audible signal devices shall be installed in a service space referred to in Sentence 3.2.1.1.(8) and shall be connected to the fire alarm system.
(12)Audible signal devices within dwelling units that are wired on separate signal circuits in accordance with Clause (10)(b) need not include a means for manual signal silencing as required by Sentence (8), provided the fire alarm system includes a provision for the automatic signal silence within dwelling units, where
(a)the automatic signal silence cannot occur within the first 60 s of operation or within the zone of initiation,
(b)a subsequent alarm elsewhere in the building will reactuate the silenced audible signal devices within dwelling units,
(c)after a period of not more than 10 min, the silenced audible signal devices will be restored to continuous audible signal if the alarm is not acknowledged, and
(d)the voice communication systems referred to in Article 3.2.4.22. and 3.2.4.23. has a provision to override the automatic signal silence to allow the transmission of voice messages through silenced audible signal device circuits that serve the dwelling units. (See Note A-3.2.4.18.(12))
(13)If a 2-stage fire alarm system has been installed with an automatic signal silence as described in Sentence (12), the system shall be designed so that any silenced audible signal devices serving dwelling units are reactuated whenever an alarm signal is required to be transmitted as part of the second stage. (See Note A-3.2.4.18.(8))
Open OBC Div. B 3.2.4.18. in the code viewer
OBC Div. B 3.2.4.19. Visible Signals
(1)Except as permitted by Sentence (4), where a fire alarm system is installed, visible signal devices shall be installed in addition to alarm signal devices
(a)in a building or portions thereof intended for use primarily by persons with a hearing impairment,
(b)in assembly occupancies in which music and other sounds associated with performances could exceed 100 dBA,
(c)in any floor area in which the ambient noise level is more than 87 dBA,
(d)in any floor area in which the occupants
(i)use ear protection devices,
(ii)are located in an audiometric booth, or
(iii)are located in sound-insulating enclosures,
(e)in public corridors serving a Group A, B, C, D or E major occupancy,
(f)in a corridor used by the public and in a floor area or part of a floor area where the public may congregate in a Group A occupancy,
(g)in not less than 10% of the suites of a hotel or motel, (See Note A-3.2.4.19.(1)(g))
(h)in washrooms for public use described in Sentence 3.8.2.3.(2), (3), (4) or (6), and
(i)in living spaces in a suite of residential occupancy in a Group C major occupancy apartment building.
(2)Visible signal devices are permitted to be installed in lieu of audible signal devices in the compartments referred to in Article 3.3.3.6. (See Note A-3.2.4.19.(2))
(3)Visible signal devices required by Sentence (1) shall be installed so that the signal from at least one device is visible throughout the floor area or portion thereof in which they are installed. (See Note A-3.2.4.19.(3))
(4)Visible signal devices required by Clauses (1)(e) and (f) are not required in
(a)a classroom, and
(b)a Group B, Division 3 occupancy that contains sleeping accommodation for not more than 10 persons and not more than six occupants require assistance in evacuation in case of an emergency.
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OBC Div. B 3.2.4.23. One-Way Voice Communication Systems
(1)Except for Group B, Division 1 and Group F, Division 1 major occupancies, where a fire alarm system is required under Subsection 3.2.4., a one-way voice communication system shall be installed in buildings where a 2-stage fire alarm system is installed and whose occupant load exceeds 1,000.
(2)The one-way voice communication system required by Sentence (1) shall consist of loudspeakers that are
(a)operated from the central alarm and control facility or, in the absence of a central alarm and control facility, from a designated area, and
(b)except in elevator cars, designed and located so that transmitted messages are audible and intelligible in all parts of the building. (See Note A-3.2.4.22.(1)(b))
(3)Where the facility is not equipped with staff trained to provide instructions over the loudspeakers, a pre-recorded message shall be provided.
(4)The voice communication system required by Sentence (1) shall meet the silencing and transmission requirements of Sentences 3.2.4.22.(2) to (4) and (6).
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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.
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OBC Div. A 1.4.1.2.(1) Alarm signal
Alarm signal means an audible signal transmitted throughout a zone or zones or throughout a building to advise occupants that a fire emergency exists.
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OBC Div. A 1.4.1.2.(1) Alert signal
Alert signal means an audible signal to advise designated persons of a fire emergency.
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OBC Div. B 3.2.4.20. Smoke Alarms
(1)Except as provided in Article 3.2.4.21., smoke alarms shall be installed in accordance with this Article.
(2)Except as permitted by Sentence (10), smoke alarms conforming to CAN/ULC-S531, "Standard for Smoke Alarms," shall be installed in each dwelling unit and, except for care, care and treatment or detention occupancies required to have a fire alarm system, in each sleeping room not within a dwelling unit.
(3)At least one smoke alarm shall be installed on each storey and mezzanine of a dwelling unit.
(4)On any storey of a dwelling unit containing sleeping rooms, a smoke alarm shall be installed
(a)in each sleeping room, and
(b)in a location between the sleeping rooms and the remainder of the storey, and if the sleeping rooms are served by a hallway, the smoke alarm shall be located in the hallway.
(5)Reserved.
(6)A smoke alarm shall be installed on or near the ceiling.
(7)Reserved.
(8)Reserved.
(9)Except as permitted by Sentence (10), smoke alarms referred in Sentence (2) shall
(a)be installed with permanent connections to an electrical circuit,
(b)have no disconnect switch between the overcurrent device and the smoke alarm, and
(c)in case the regular power supply to the smoke alarm is interrupted, be provided with a battery as an alternative power source that can continue to provide power to the smoke alarm for a period of not less than 7 days in the normal condition, followed by 4 minutes of alarm. (See Note A-3.2.4.20.(9))
(10)Suites of residential occupancy are permitted to be equipped with smoke detectors in lieu of smoke alarms, provided the smoke detectors
(a)are capable of independently sounding audible signals with a sound pressure level between 75 dBA and 110 dBA within the individual suites, (See also Note A-3.2.4.18.(4))
(b)except as permitted by Sentence (11), are installed in conformance with CAN/ULC-S524, "Standard for the Installation of Fire Alarm Systems," and verified in conformance with CAN/ULC-S537, "Standard for the Verification of Fire Alarm Systems,"
(c)form part of the fire alarm system, and
(d)are equipped with visual signalling components that meet the requirements of Sentences (17) to (19). (See Note A-3.2.4.20.(10))
(11)Smoke detectors permitted to be installed in lieu of smoke alarms as stated in Sentence (10) are permitted to sound localized alarms within individual suites, and need not sound an alarm throughout the rest of the building.
(12)If more than one smoke alarm is required in a dwelling unit, the smoke alarms shall be interconnected so that the actuation of one smoke alarm will cause all smoke alarms within the dwelling unit to sound.
(13)A smoke alarm required by Sentence (2) shall be installed in conformance with CAN/ULC-S553, "Standard for Installation of Smoke Alarms."
(14)Except as permitted in Sentence (15), a manually operated silencing device shall be incorporated within the circuitry of a smoke alarm installed in a dwelling unit so that it will silence the signal emitted by the smoke alarm for a period of not more than 10 min, after which the smoke alarm will reset and again sound the alarm if the level of smoke in the vicinity is sufficient to reactuate the smoke alarm.
(15)Suites of residential occupancy equipped with smoke detectors installed in conformance with CAN/ULC-S524, "Standard for Installation of Fire Alarm Systems," as part of the fire alarm system in lieu of smoke alarms as permitted by Sentence (10), need not incorporate the manually operated silencing device required by Sentence (14). (See Note A-3.2.4.20.(10))
(16)The sound patterns of smoke alarms shall
(a)meet the temporal patterns of alarm signals, or (See Note A-3.2.4.18.(2))
(b)be a combination of temporal pattern and voice relay.
(17)Smoke alarms required by Sentence (2) shall have a visual signalling component conforming to the requirements in 18.5.3. (Light, Color and Pulse Characteristics) of NFPA 72, "National Fire Alarm and Signaling Code." (See Note A-3.2.4.20.(17))
(18)The visual signalling component required by Sentence (17) need not
(a)be integrated with the smoke alarm provided it is interconnected to it,
(b)be on battery backup, or
(c)have synchronized flash rates, when installed in a dwelling unit.
(19)The luminous intensity for visual signalling components required by Sentence (17) that are installed in sleeping rooms shall be a minimum of 175 cd.
(20)Smoke alarms required in suites in a retirement home or smoke detectors permitted to be installed in lieu of smoke alarms as provided in Sentence (10) shall upon actuation provide an audible and visual signal to staff serving those suites, so that the suite containing the actuated smoke alarm or smoke detector can be easily identified.
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OBC Div. B 3.2.4.21. Residential Fire Warning Systems
(1)Except where a fire alarm system is installed or required in a building, smoke detectors forming part of a residential fire warning system installed in conformance with CAN/ULC-S540, "Standard for Residential Fire and Life Safety Warning Systems: Installation, Inspection, Testing and Maintenance," are permitted to be installed in lieu of all smoke alarms required by Article 3.2.4.20., provided that the system is
(a)capable of sounding audible signals in accordance with Sentences 3.2.4.20.(12) and (16),
(b)provided with a visual signalling component in accordance with Sentences 3.2.4.22.(17) to (19),
(c)powered in accordance with Sentence 3.2.4.20.(9), and
(d)provided with a silencing device in accordance with Sentences 3.2.4.20.(14) and (15).
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