NCC 2016 Volume One
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Part E2 Smoke Hazard Management (Deemed-to-Satisfy Provisions)
Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements to are satisfied by complying with—
in a building in an alpine area, Part G4; and
for additional requirements for Class 9b buildings, Part H1.
Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A0.7.
To clarify that the requirements of and will be satisfied if compliance is achieved with to in the case of all buildings, in the case of buildings with an atrium, in the case of buildings in alpine areas, in the case of theatres, stages and public halls.
to and and
Where a solution is proposed to comply with the Deemed-to-Satisfy Provisions, except in buildings containing atriums, compliance with to achieves compliance with and .
Buildings with atriumsIn addition to achieving compliance with to , to achieve compliance with and buildings with atriums must also comply with .
Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with . (See comment on A0.7).
The Deemed-to-Satisfy Provisions of this Part do not apply to—
any open deck carpark; or
any open spectator stand; or
a Class 8 electricity network substation with a floor area not more than 200 m2, located within a multi-classified building.
The smoke exhaust and smoke-and-heat vent provisions of this Part do not apply to any area not used by occupants for an extended period of time such as a storeroom with a floor area less than 30 m2, sanitary compartment, plant room or the like.
To specify when and do not apply.
, and do not apply to open-deck carparks or open spectator stands. does not apply to such buildings because the smoke and hot gases can vent naturally.
The Deemed-to-Satisfy Provisions of Part E2 do not apply to small Class 8 electricity network substations, located in a multi-classified building. These smaller substations are usually located within a "host" building and the associated electrical equipment has its own sensitive dedicated systems that provide a rapid response signal to a central control room that is constantly staffed.
Smoke exhaust systems and smoke-and-heat vents—E2.1(b)Under , the and provisions regarding smoke exhaust systems and smoke-and-heat vents do not apply to small areas used for short periods.
A small area will be easily evacuated before smoke build-up and if the area is only used for short periods, the risk of occupants being trapped in it during a fire is low.
A building must comply with (b), (c), (d) and—
Table E2.2a as applicable to Class 2 to 9 buildings such that each separate part complies with the relevant provisions for the classification; and
Table E2.2b as applicable to Class 6 and 9b buildings such that each separate part complies with the relevant provisions for the classification.
An air-handling system which does not form part of a smoke hazard management system in accordance with Table E2.2a or Table E2.2b and which recycles air from one fire compartment to another fire compartment or operates in a manner that may unduly contribute to the spread of smoke from one fire compartment to another fire compartment must—
be designed and installed to operate as a smoke control system in accordance with AS/NZS 1668.1; or
incorporate smoke dampers where the air-handling ducts penetrate any elements separating the fire compartments served; and
be arranged such that the air-handling system is shut down and the smoke dampers are activated to close automatically by smoke detectors complying with clause 7.5 of AS 1670.1; and
for the purposes of this provision, each sole-occupancy unit in a Class 2 or 3 building is treated as a separate fire compartment.
Miscellaneous air-handling systems covered by Sections 5 and 6 of AS/NZS 1668.1 serving more than one fire compartment (other than a carpark ventilation system) and not forming part of a smoke hazard management system must comply with that Section of the Standard.
A smoke detection system must be installed in accordance with Clause 5 of Specification E2.2a to operate AS/NZS 1668.1 systems that are provided for zone smoke control and automatic air pressurisation for fire-isolated exits.
To specify the requirements for minimising the smoke risks.
Class 2–9 buildings must comply with , and , which cover the fire mode operation of air-handling systems so that they do not contribute to the spread of smoke during a fire. This assists to maintain the basic smoke integrity of the fire compartments.
In addition to , and , Class 2–9 buildings must comply with the requirements of , which provides some general and specific strategies for smoke hazard management.
In addition to , and and , Class 6 and Class 9b buildings must comply with the requirements of , where applicable, which provides some general and specific strategies for smoke hazard management.
Air-handling system which is not part of a smoke hazard management system—E2.2(b)
Smoke must not cross smoke barriers
requires that an air-handling system that is not part of a smoke hazard management system be designed and installed with suitable strategies to ensure that, during a fire, it does not:
The effect of is that in a fire, an air-handling system must either operate as a smoke control system in accordance with AS/NZS 1668.1 (as specified in ) or shut down (as specified in ).
A smoke purging system, in accordance with AS/NZS1668.1, is allowable in buildings not covered by the general provisions in , and, in some instances, in conjunction with other measures in accordance with .
Non-smoke control system—An air-handling system not designed as a smoke control system must comply with the requirements set out in as follows:
Where the air-handling system is shut down in fire mode, it must incorporate automatic smoke dampers where the ducts penetrate any fire barriers.
This requirement may apply to an air-handling system which supplies outside air to a group of residential sole-occupancy units.
The air handling system must shut down, and smoke detectors must automatically activate smoke dampers.
Sole-occupancy units in Class 2 and Class 3 buildings are, under , regarded as separate fire compartments.
Sections 5 and 6 of AS/NZS 1668.1—Air-handling systems, other than one in a carpark, serving more than one fire compartment covered by Sections 5 and 6 of AS/NZS 1668.1 must be designed and installed in compliance with those sections of the Australian Standard. This will restrict the spread of smoke between fire compartments.
Provisions on the operation of carpark ventilation systems during a fire in the carpark are included under the general provisions in .
Smoke detection systems to operate AS/NZS 1668.1 smoke control systems—An AS/NZS 1668.1 system for zoned smoke control and automatic air pressurisation for fire-isolated exits must be controlled by a smoke detection and alarm system installed in compliance with ,strong>Specification E2.2a. Activation of these systems also requires the activation of a building occupant warning system.
Additional smoke hazard management measures may be necessary due to the—
special characteristics of the building; or
special function or use of the building; or
special type or quantity of materials stored, displayed or used in a building; or
special mix of classifications within a building or fire compartment,
which are not addressed in Tables E2.2a and E2.2b.
Table E2.2a GENERAL PROVISIONS
FIRE-ISOLATED EXITS |
A required—
|
Notes: |
BUILDINGS MORE THAN 25 M IN EFFECTIVE HEIGHT |
CLASS 2 AND 3 BUILDINGS AND CLASS 4 PART OF A BUILDING |
A Class 2 and 3 building or part of a building and Class 4 part of a building must be provided with an automatic smoke detection and alarm system complying with Specification E2.2a. |
Note: Refer C2.14 for division of public corridors greater than 40 m in length. |
CLASS 5, 6, 7b, 8 or 9b BUILDINGS |
A Class 5, 6, 7b, 8 or 9b building or part of a building must be provided with a zone smoke control system in accordance with AS/NZS 1668.1. |
Notes:
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CLASS 9a BUILDINGS |
A Class 9a building must be provided with—
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Notes A building more than 25 m in effective height requires a sprinkler system under E1.5. |
BUILDINGS NOT MORE THAN 25 M IN EFFECTIVE HEIGHT |
CLASS 2 AND 3 BUILDINGS AND CLASS 4 PART OF A BUILDING |
A Class 2 and 3 building or part of a building and Class 4 part of a building—
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Notes:
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CLASS 5, 6, 7b, 8 and 9b BUILDINGS |
In a—
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LARGE ISOLATED BUILDINGS SUBJECT TO C2.3 |
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Notes:
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CLASS 9a and 9c BUILDINGS |
A Class 9a health-care building or a Class 9c building, or a building containing a part thereof, must be provided throughout with—
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Note: Refer to Clause 2 of Specification C2.5 for the provisions for smoke dampers. |
CLASS 7a BUILDINGS |
A Class 7a building, including a basement, provided with a mechanical ventilation system in accordance with AS 1668.2 must comply with clause 5.5 of AS/NZS 1668.1 except that—
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BASEMENTS (other than Class 7a buildings) |
A basement, not counted in the rise in storeys in accordance with C1.2, must—
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Notes:
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ATRIUMS |
Refer Part G3. |
Table E2.2b SPECIFIC PROVISIONS
CLASS 6 BUILDINGS — IN FIRE COMPARTMENTS MORE THAN 2000 m |
CLASS 6 BUILDINGS (not containing an enclosed common walkway or mall serving more than one Class 6 sole-occupancy unit); |
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CLASS 6 BUILDINGS (containing an enclosed common walkway or mall serving more than one Class 6 sole-occupancy unit) |
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Note: A fire compartment having a floor area of more than 3500 m2 in a Class 6 building requires a sprinkler system under E1.5. |
CLASS 9b — ASSEMBLY BUILDINGS |
NIGHTCLUBS and DISCOTHEQUES AND THE LIKE |
A building or part of a building used as a nightclub, discotheque or the like must be provided with—
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EXHIBITION HALLS |
A building or part of a building used as an exhibition hall must be provided with—
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THEATRES and PUBLIC HALLS |
A building or part of a building used as a theatre or public hall which—
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THEATRES and PUBLIC HALLS (not listed above) INCLUDING LECTURE THEATRES AND CINEMA/AUDITORIUM COMPLEXES |
A building or part of a building used as a theatre or public hall (not listed above) including a lecture theatre and cinema/auditorium complex—
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OTHER ASSEMBLY BUILDINGS (not listed above) and EXCLUDING SCHOOLS |
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To state that some special hazards may require additional smoke hazard management measures.
states that certain factors may need additional smoke hazard management measures.
reinforces the need for careful consideration and sound professional judgement in the application of the smoke hazard management provisions of the BCA.
may be applicable in situations where:
Deemed-to-Satisfy Provisions— and
—General Provisions
Table E2.2a and and
requires automatic warning on the detection of smoke in buildings having sleeping accommodation, so that occupants may be alerted to the fire hazard. , in terms of maintaining safe conditions in any evacuation route, deals with the period of time it would take occupants to evacuate that part of the building.
provides whole-building strategiesprovides smoke hazard management strategies structured to help application to buildings of mixed classification. In the case of a multi-classified building, each classifiable part must comply with the relevant provisions for its classification. Certain Class 6 and Class 9b parts of buildings must also comply with the specific provisions in .
Fire-isolated exitsFire-isolated exits enable the safe evacuation of occupants, and also aid fire brigade access. Smoke must not unduly affect the conditions in such exits during an evacuation.
To minimise smoke intrusion, the exits may need to be pressurised with outside air for the entire exit route. See the following examples. Alternatively, the exits may be provided with open access ramps or balconies from which smoke can vent naturally.
Pressurised fire-isolated exits are required where:
In buildings more than 25 metres in effective height, tenable conditions need to be maintained in the fire-isolated exits and, where practicable, in other parts of the building to enable the staged evacuation of occupants.
Occupants of such buildings may continue to occupy compartments remote from the fire for an extended time before evacuation. Accordingly, suitable measures must be adopted to minimise the spread of smoke from the fire-affected compartment to non-affected compartments by way of a number of potential leakage paths.
These paths include lift shafts, air-handling ducts, services risers, building penetrations, spandrels, and the like, through which smoke can be driven by buoyancy, expansion, stack and wind effects, and air-handling systems.
In order to minimise the spread of smoke, a zone smoke control system is considered necessary in buildings more than 25 metres in effective height. This does not apply to the residential parts of a building in view of:
Additionally, this requirement does not apply to a building that contains only one single fire compartment containing a Class 5, 6, 7b, 8 or 9b part (or a combination of these classes in the same fire compartment) in an otherwise Class 2, 3, 9a or 9c building. Reference to a Class 2, 3, 9a or 9c building does not include a building that also contains a Class 7a carpark (see Figure E2.2a). The reasons for this exemption are:
Notwithstanding the above, a smoke detection and alarm system must be provided in residential and health-care buildings to provide early warning to occupants who may be asleep, confused, or non-ambulatory and dependent on assistance.
Figure E2.2a ZONE SMOKE CONTROL CONCESSION |
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Building A | Although the building has only one fire compartment containing a Class 5, 6, 7b, 8 or 9b part, the concession does not apply because the building contains a Class 7a part. |
Building B | A zone smoke control system is required because the building contains more than one fire compartment containing a Class 5, 6, 7b, 8 or 9b part. |
Building C | A zone smoke control system is not required because the building has only one fire compartment containing a Class 5, 6, 7b, 8 or 9b part and the remainder of the building is solely Class 2. |
provisions are additional to other safety provisions for buildings with an effective height of more than 25 metres.
Buildings less than 25 metres in effective heightIn buildings less than 25 metres in effective height, the necessary levels of protection may be achieved by measures other than zone smoke control, depending on the Class and rise in storeys of the building.
In buildings other than health-care buildings, zone smoke control may be substituted by either stairway pressurisation, smoke detection, or sprinkler protection. The rise in storeys before which the provisions become applicable depends on the building’s classification and use.
The above measures do not apply to the residential parts of a building because of the passive protection provided to such parts. However, where one or more fire-isolated exits join residential and non-residential parts, other than open-deck carparks, the fire-isolated exits must either be pressurised, or the non-residential parts provided with smoke detection or sprinkler protection. This is necessary to compensate for the potential additional hazard associated with the particular mix of Classes.
In health-care buildings, zone smoke control may be substituted by a sprinkler system, providing residential sprinkler heads are used in patient care areas. The fast response of residential sprinkler heads promotes life safety by limiting fire growth and smoke development. Where zone control is not adopted, the air-handling systems must generally be shut down not only to maintain the integrity of the smoke and fire compartmentation, but also to minimise the spread of smoke within the fire-affected compartment.
Notwithstanding the above, a smoke detection and alarm system must be provided in residential and health-care buildings.
Large Class 7 or 8 buildings subject to C2.3These provisions set out the smoke hazard management measures for large isolated Class 7 or 8 buildings subject to the requirements of with a floor area of 18 000 m2 or less and a volume of 108 000 m3 or less. Such buildings are required to have:
These provisions set out the smoke hazard management measures for large isolated Class 5 to 9 buildings subject to the requirements of having a floor area exceeding 18 000 m2 or having a volume exceeding 108 000 m3.
Such buildings are required to have:
Roller shutters and doors can be used for smoke venting purposes in accordance with the table if they are “readily openable”. A building proponent must satisfy the appropriate authority that such roller shutters and doors achieve the “readily openable” requirement.
However, if the openings are also used for egress purposes, they must also comply with the requirements of relevant provisions such as and .
Class 7a buildingsA carpark ventilation system is consistent with the treatment of miscellaneous air-handling systems in AS/NZS 1668.1. Accordingly, the electric power and control cabling for a carpark ventilation system need not be fire rated.
Likewise, a concession is granted to allow fans with metal blades suitable for operating at normal temperatures to be used instead of fans required to operate at elevated temperatures as required by Clause 4.8.1 of AS 1668.1>.
To make sure that the manual override provision of Clause 5.5.3 of AS/NZS 1668.1 is not subject to the control of any general installation main switches, the power supply arrangement must comply with AS 3000.
Basements (other than Class 7a buildings)The provisions for basements are more stringent due to the special problems they pose for evacuation, search and rescue, and firefighting operations.
As the total floor area of the basement increases to above 2 000 m2, certain minimum measures have been stipulated. In basements with three or more below ground storeys, a sprinkler system is considered necessary.
AtriumsThe provisions of this Part, as well as Part G3, apply to atrium buildings.
—Specific Provisions
Table E2.2b and Class 6 and Class 9b buildings
The provisions of are additional strategies which only apply to certain Class 6 and Class 9b buildings where there is a high risk that occupants may not be able to safely evacuate the fire-affected compartment. This risk may be due to factors such as:
Occupants of such buildings are also not necessarily familiar with the building or the procedures for evacuation.
Maintenance of safe conditions in evacuation routesaddresses requirements under in terms of maintaining safe conditions in any evacuation route within the fire-affected compartment of Class 6 and Class 9b buildings, for the period of time it would take occupants to evacuate that part of the building.
Class 6 buildingsThere are specific provisions for large Class 6 buildings in for the installation of either an automatic smoke exhaust system or automatic smoke-and-heat vents to control smoke during a fire. These apply to the whole fire compartment where the floor area of the Class 6 part of the fire compartment is more than 2 000 m2.
There are specific concessions that vary these requirements. These are—
Example 1 looks at a single storey shopping complex which does not contain a mall, as shown in Figure E2.2b(1). The fire compartment has a floor area of 5 300 m2, so smoke exhaust/venting is required. The floor area of the fire compartment is more than 3 500 m2, therefore a smoke detection and alarm system or a sprinkler system cannot be used in lieu of smoke exhaust venting. However, smoke exhaust venting need not be provided in shops A and C because their individual floor areas are less than 2 000 m2, they are not interconnected to shop B, and their main entrances open to a road or open space.
Smoke exhaust or smoke-and-heat venting must be provided to shop B.
Shop | Area | Entry | Smoke exhaust OR smoke-and-heat vents OR smoke detection and OR sprinkler system |
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A | 900 m2 |
From open space | None required |
B | 2500 m2 | From open space | Smoke exhaust or smoke-and-heat venting required as the floor area exceeds 2 000 m2 |
C | 1900 m2 | From open space | None required |
Figure E2.2b(1) PLAN OF SHOPPING CENTRE FOR EXAMPLE 1 |
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The specific smoke hazard management provisions for Class 6 buildings containing shops and an enclosed common walkway or mall are similar. Where such a building has a fire compartment with a floor area of more than 2 000 m2, an automatic smoke exhaust system or an automatic smoke-and-heat vent system to control smoke during a fire is required.
However, where a single storey shop does not open onto the mall and its main public entrance opens to a road or open space, it does not need to have any smoke exhaust or smoke venting, if its floor area does not exceed 2 000 m2. This is similar to the concession for a shop in a building which does not contain a mall.
Another concession applies to shops that open onto the mall. They do not need to have any smoke exhaust or smoke venting system if their individual floor areas are less than 1 000m2.
A concession is also available for another part of the building with a different classification (i.e. other than Class 6) which is smoke separated, including openings, junctions and joints of building elements, etc., from the Class 6 part.
In a Class 6 building containing a mall, a sprinkler system can also be used in lieu of a required automatic smoke exhaust system or an automatic smoke-and-heat vent system, if the floor area of the whole fire compartment is not more than 3 500 m2.
Example 2 looks at a single storey shopping complex containing a mall, as shown in Figure E2.2b(2). The fire compartment is 15 900 m2, therefore smoke exhaust/venting is required (if the floor area of the fire compartment had been less than 3 500 m2, a sprinkler system could have been used instead of a smoke exhaust/venting system). Smoke exhaust or venting is not required to shop B, which opens onto the mall, because the floor area is less than 1 000 m2. It is also not required to shop D, because the floor area is less than 2 000 m2, it does not open onto the mall, and the main entrance is to a road or open space.
Shop | Area | Entry | Smoke exhaust OR smoke-and-heat vents |
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A | 900 m2 | From open space | None required as it is single storey, the floor area is less than 2 000 m2 and the main entrance opens to a road or open space |
B | 900 m2 | From mall | None required as the floor area is less than 1 000 m2 |
C | 900 m2 | From mall and open space | None required as the floor area is less than 1 000 m2 |
D | 1 900 m2 | From open space | None required as it is single storey, the floor area is less than 2 000 m2 and the main entrance opens to a road or open space |
E | 1 900 m2 | From mall | Required as the floor area is over 1 000 m2 and opens onto mall |
F | 1 900 m2 | From mall and open space | Required as the floor area is over 1 000 m2 and opens onto mall |
G | 2 500 m2 | From open space | Required as the floor area is more than 2 000 m2 |
H | 2 500 m2 | From mall | Required as the floor area is over 1 000 m2 and opens onto mall |
I | 2 500 m2 | From mall and open space | Required as the floor area is over 1 000 m2 and opens onto ma |
Mall | - | - | Required as the fire compartment has a floor area over 2 000 m2 |
Figure E2.2b(2) PLAN OF SHOPPING CENTRE FOR EXAMPLE 2 |
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Class 9 assembly buildings
Table E2.2b —greater uniformity and consistency
Assembly buildings cover a wide range of uses with varying degrees of hazards. addresses some of the uses to enable greater uniformity in the treatment of the buildings or parts of buildings. It provides for assembly buildings generally, except for certain low hazard occupancies which have been exempted from compliance.
Exempted assembly buildingsCertain provisions for assembly buildings do not apply to schools, apart from the automatic shutdown of air-handling systems in lecture theatres. This is because such buildings may have alarm systems with which the occupants are familiar, and the occupants are usually under a sufficient level of control to enable quick and orderly evacuation.
Concessions are granted for sporting complexes, excluding indoor stadiums with total spectator seating of more than 1000, principally because the risk levels are not high, particularly with regard to open-air complexes. Buildings used solely for religious worship are also exempt.
Assembly buildings with floor area over 2 000 m 2The provisions for smoke exhaust or smoke-and-heat vents are applicable to fire compartments having a floor area of more than 2 000 m2, except that certain concessions apply to low rise buildings.
If the floor area of the fire compartment is not more than 5 000 m2, smoke extraction need not be provided if the building has a rise in storeys of two or less, and a smoke detection and alarm system, or a sprinkler system is installed.
Nightclubs, discotheques and the likeThe provisions apply to all nightclubs, discotheques and the like, regardless of the floor area, in recognition of the high hazards generated by such factors as:
The provisions for exhibition halls which are used for trade displays and the like are based on them having hazards similar to those for shopping centres and indoor markets.
Theatres and public hallsThe provisions only apply to those theatres and public halls which are considered a high hazard occupancy due to the potential fire load associated with the stage and backstage areas and/or rigging lofts. Under Part H1, such theatres and public halls are also required to be sprinkler protected or have the stage and backstage areas separated from the audience by a proscenium wall.
The provisions for these occupancies are similar to those for assembly buildings. The provision for automatic shutdown of air-handling systems (which do not form part of a smoke management system) is applicable in all such buildings, including those serving school lecture theatres not more than 2 000 m2 in area.
Other assembly buildingsincludes provisions for general assembly buildings not covered elsewhere. Museums and art galleries with fire compartments in excess of 2000 m2 are covered by these provisions.