NCC 2016 Volume One
Search the National Construction Code editions
Classification
Building class 1a Building class 1b Building class 2 Building class 3 Building class 4 Building class 5 Building class 6 Building class 7a Building class 7b Building class 8 Building class 9a Building class 9b Building class 9c Building class 10a Building class 10b Building class 10c

Filter

Classification
Building class 1a Building class 1b Building class 2 Building class 3 Building class 4 Building class 5 Building class 6 Building class 7a Building class 7b Building class 8 Building class 9a Building class 9b Building class 9c Building class 10a Building class 10b Building class 10c
Part C1 Fire Resistance and Stability

Part C1 Fire Resistance and Stability

C1.0 Deemed-to-Satisfy Provisions

(a)

Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements to are satisfied by complying with—

(ii)

in a building containing an atrium, Part G3; and

(iii)

for additional requirement for Class 9b buildings, Part H1; and

(iv)

for farm sheds, Part H3.

(b)

Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A0.7.

Intent

To clarify that the requirements of to will be satisfied if a building complies with Parts C1, and , and Parts G3, and , if applicable.

Most buildings

Where a solution is proposed to comply with the Deemed-to-Satisfy Provisions, clarifies that for most buildings compliance with Parts C1, and will achieve compliance with to . The exceptions to this general rule are as follows:

  • If the building contains an atrium, it must comply with Part G3 in addition to Parts C1, and .
  • If the building comprises of a theatre, stage or public hall it must comply with Part H1 in addition to Parts C1, and .
  • If the building contains an atrium and one or more theatre, stage or public hall, it must comply with Parts C1, , , and .
  • Farm sheds must comply with in addition to Parts C1, and .

Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with . (See comment on A0.7).

C1.1 Type of construction required

(a)

The minimum Type of fire-resisting construction of a building must be that specified in Table C1.1 and Specification C1.1, except as allowed for—

(i)

certain Class 2, 3 or 9c buildings in C1.5; and

(ii)

a Class 4 part of a building located on the top storey in C1.3(b); and

(iii)

open spectator stands and indoor sports stadiums in C1.7.

(iv)

* * * * *

SA C1.1(a)(v)

(b)

Type A construction is the most fire-resistant and Type C the least fire-resistant of the Types of construction.

TABLE C1.1 TYPE OF CONSTRUCTION REQUIRED

Rise in storeys Class of building
2, 3, 9 5, 6, 7, 8
4 OR MORE A A
3 A B
2 B C
1 C C

SA C1.1(c) and (d)

Intent

To establish the minimum fire-resisting construction required for Class 2–9 buildings.

Minimum type of construction required

sets out the minimum type of fire-resisting construction required by the Deemed-to-Satisfy Provisions for all Class 2–9 buildings.

explains that Type A construction is the most fire-resistant, Type C construction is the least fire-resistant, and Type B construction falls between these two.

Class and height (rise in storeys)

explains that the required type of construction of a building depends on risk levels as indicated by the Class of building and the building’s height as indicated by the rise in storeys. Note that there could be other factors that need to be considered. For example, and examine the maximum permissible size of fire compartments or atriums in buildings for specific types of construction.

Class of building

The Class of building is a measure of the building’s likely:

  • use;
  • fire load;
  • population; and
  • mobility of the occupants, such as whether they are sleeping or alert.

Example

Example

Research indicates that if a fire occurs while a person is asleep, the smell of the smoke will not wake them. Response times in residential buildings are longer than in other types of buildings. The BCA thus requires a higher type of construction in residential buildings. See Table C1.1.

Height of building (rise in storeys)

The height (rise in storeys) of the building is relevant as a measure of likely evacuation times and evacuation difficulty.

Types of construction and Alternative Solutions

When using a Alternative Solution, Part C1 does not apply and there is no need to refer to the types of construction. Nonetheless, if building proponents using Alternative Solutions wish to use Part C1 as part of the solution, they can.

C1.2 Calculation of rise in storeys

(a)

The rise in storeys is the sum of the greatest number of storeys at any part of the external walls of the building and any storeys within the roof space—

(i)

above the finished ground next to that part; or

(ii)

if part of the external wall is on the boundary of the allotment, above the natural ground level at the relevant part of the boundary.

(b)

A storey is not counted if—

(i)

it is situated at the top of the building and contains only heating, ventilating or lift equipment, water tanks, or similar service units or equipment; or

(ii)

it is situated partly below the finished ground and the underside of the ceiling is not more than 1 m above the average finished level of the ground at the external wall, or if the external wall is more than 12 m long, the average for the 12 m part where the ground is lowest.

(c)

In a Class 7 or 8 building, a storey that has an average internal height of more than 6 m is counted as—

(i)

one storey if it is the only storey above the ground; or

(ii)

2 storeys in any other case.

(d)

For the purposes of calculating the rise in storeys of a building—

(i)

a mezzanine is regarded as a storey in that part of the building in which it is situated if its floor area is more than 200 m2 or more than 1/3 of the floor area of the room, whichever is the lesser; and

(ii)

two or more mezzanines are regarded as a storey in that part of the building in which they are situated if they are at or near the same level and have an aggregate floor area more than 200 m2 or more than 1/3 of the floor area of the room, whichever is the lesser.

Intent

To establish a method for the calculation of the rise in storeys of a building, as a means of helping determine a building’s required type of construction.

What is the rise in storeys?—C1.2(a)

Under , the rise in storeys is the sum of the greatest number of storeys at any part of the external walls of a building above ground level and any storeys within the roof space. The reason for the inclusion of any storey within the roof space is that the storey may not have any external walls such as occur with a hip roof.

and distinguish between the situation where the part of the external walls is within the allotment (in which case it is calculated above finished ground level—), or on the allotment boundary (in which case it is calculated above natural ground level at that point—).

The rise in storeys is the criteria used to determine the type of construction. This is because the rise in storeys has an impact on:

  • the risk of exposure to radiant heat from a fire in another building;
  • the risk of emitting radiant heat to another building; and
  • the risk to occupants who may need to travel down a stairway to safely evacuate the building.
Definition of storey

“Storey” is defined in . It is advisable to refer to this definition before calculating the rise in storeys of a building.

Calculation of rise in storeys

The calculation of the rise in storeys includes larger mezzanines (see ) and situations where two or more mezzanines can create a similar impact to larger mezzanines (see ) because of their potential fire load.

The calculation excludes machinery or similar plant rooms at the top of the building because they do not add significantly to the building’s fire load (see ) and storeys below ground level in particular circumstances outlined in Figure C1.2(1). This is because basements are not exposed to radiant heat from a fire in another building, nor do they emit any significant heat horizontally.

describes when storeys partly below ground level are not included in the calculation of the rise in storeys, i.e. when they are treated as basement storeys as described above. Whether a storey is to be excluded from the calculation of the rise in storeys is determined by measuring the extent of the storey above the average ground level at the external wall. If the wall is more than 12 m long, consider only the 12 m length of the wall where the average ground level is lowest. If any wall of a storey is more than 1 m above the average ground level, the storey is included in the calculation of the rise in storeys.

The height of a ceiling in a storey above the average ground level adjacent to the external wall can be determined by calculating the area between the ground level and the ceiling for the length of the wall under consideration (the actual length of the wall or 12 metres, whichever is the lesser) and dividing the area obtained by that length (see Figure C1.2(3)).

Class 7 or 8 with internal storey height over 6 metres—C1.2(c)

Under , a Class 7 or Class 8 building with more than one storey above ground level (see ) and which has an internal storey height of 6 metres or more is, from the point of view of potential fire load, considered to be the equivalent to 2 storeys (see ).

Examples of calculating rise in storeys

illustrates some examples of calculating the rise in storeys of a building.

Figure C1.2(1)

SECTION SHOWING STOREY BELOW GROUND LEVEL INCLUDED IN RISE IN STOREYS
guide_C121_2005.svg

Figure C1.2(2)

EXAMPLES OF CALCULATING THE RISE IN STORIES OF A BUILDING
guide_C122_2012.svg

Figure C1.2(3)

DETERMINATING THE HEIGHT ABOVE AVERAGE LEVEL OF THE GROUND

guide_C123a_2008.svg

guide_C123b_2008.svg
Note: If the wall is more than 12 m long, consider only the 12 m length of the wall wherethe average finished ground level is lowest (see Figure C1.2(1))

C1.3 Buildings of multiple classification

(a)

In a building of multiple classifications, the Type of construction required for the building is the most fire-resisting Type resulting from the application of Table C1.1 on the basis that the classification applying to the top storey applies to all storeys.

(b)

In a building containing a Class 4 part on the top storey, for the purpose of (a), the classification applying to the top storey must be—

(i)

when the Class 4 part occupies the whole of the top storey, the classification applicable to the next highest storey; or

(ii)

when the Class 4 part occupies part of the top storey, the classification applicable to the adjacent part.

Intent

To establish the type of construction required for a building that contains more than one Class.

Procedure for determining type of construction

In a building comprising multiple classifications, the type of construction applicable to the classification of the top storey applies to all the storeys below it. Figure C1.3(1) illustrates this. This method is used to determine the type of construction only, and not the FRLs required for the different classifications.

Figure C1.3(1)

METHOD OF DETERMINING THE TYPE OF CONSTRUCTION REQUIRED FOR MULTI-CLASSIFIED BUILDINGS
guide_C131_2005.svg
Where a Class 4 part comprises the top storey

To determine the type of construction required when a Class 4 part of a building occupies the whole of the top storey, the class of the next highest storey must be applied to the top storey (see ). When a Class 4 part of a building occupies only part of the top storey, the required type of construction is determined by the class of the other part of the top storey (see ).

must be used to determine the appropriate FRLs for the building elements in the Class 4 part of the building.

Example

Example

In a 3 storey building with the lower 2 storeys of Class 5 and the top storey entirely of Class 4 the Class 5 classification would be applied to the top storey as shown in Figure C1.3(2). Thus the required type of construction by the use of would be at least Type B construction.

Figure C1.3(2)

MULTI-CLASSIFIED BUILDING FOR ABOVE EXAMPLE
guide_C132_2005.svg

C1.4 Mixed types of construction

A building may be of mixed Types of construction where it is separated in accordance with C2.7 and the Type of construction is determined in accordance with C1.1 or C1.3.

Intent

To specify the circumstances in which a building may be of more than one type of construction.

Separation by a fire wall

The only circumstance in which the Deemed-to-Satisfy Provisions allow a building to be of different types of construction is when the types are separated from one another by a fire wall as described in .

Different types must not be above one another

In no case do the Deemed-to-Satisfy Provisions allow different types of construction to be above one another.

C1.5 Two storey Class 2, 3 or 9c buildings

A building having a rise in storeys of 2 may be of Type C construction if—

(a)

it is a Class 2 or 3 building or a mixture of these classes and each sole-occupancy unit has—

(i)

access to at least 2 exits; or

(ii)

its own direct access to a road or open space; or

(b)

it is a Class 9c building protected throughout with a sprinkler system complying with Specification E1.5 and complies with the maximum compartment size specified in Table C2.2 for Type C construction.

Intent

To grant concessions for:

  • low-rise Class 2 and Class 3 buildings provided with a good means of egress; and
  • sprinkler protected Class 9c buildings.
Low-rise Class 2 and Class 3 buildings

The concession for Class 2 and Class 3 buildings is made on the basis that the level of risk to occupants does not warrant the full application of the type of construction requirements.

The circumstances outlined in and are alternative options. They do not have to both exist to bring the concession into operation.

The concession also applies to a building containing a mixture of Class 2 and Class 3.

illustrates an example of the use of the concession allowed by .

Low-rise Class 9c buildings

The concession for Class 9c buildings recognises the benefits of sprinkler systems and differences between Types A, B and C construction. It must be remembered that the Class 9c building must comply with all the other BCA provisions, including the floor area limitations contained in .

C1.6 Class 4 parts of buildings

For the Type of construction required by C1.3, a Class 4 part of a building requires the same FRL for building elements and the same construction separating the Class 4 part from the remainder of the building as a Class 2 part in the same Type of construction.

Intent

To specify that Class 4 parts of buildings are subject to the same requirements for fire-resistance levels (FRLs) and separation as would apply to Class 2 parts in similar circumstances.

Class 4 FRLs the same as Class 2

The reason for requiring the same FRL for a Class 4 as a Class 2 building is because the two different classifications have similar fire loads. It should be noted that the Type of construction required for a Class 4 part is determined in accordance with .

In a building fire, the people most at risk include those who are sleeping. It is therefore important that the residential part of the building be fire separated from the other parts. The fire-resistance levels (FRLs) required for structural elements in a Class 4 part of a building are identified in , or .

Figure C1.5

EXAMPLE OF THE CONCESSION ALLOWED BY C1.5
guide_C15_2005.svg

C1.7 Open spectator stands and indoor sports stadiums

(a)

An open spectator stand or indoor sports stadium may be of Type C construction and need not comply with the other provisions of this Part if it contains not more than 1 tier of seating, is of non-combustible construction, and has only changing rooms, sanitary facilities or the like below the tiered seating.

(b)

In (a), one tier of seating means numerous rows of tiered seating incorporating cross-overs but within one viewing level.

Intent

To grant a concession for open spectator stands and indoor sports stadiums.

Indoor sports stadiums

Under specified circumstances (see ), an indoor sports stadium may be of Type C construction.

The reason for this concession is that although an indoor sports stadium may have a high population, particularly during an event, it generally has a lower fire load than other Class 9b buildings. For example, in most stadiums:

  • large areas are usually inaccessible to the public (being taken up as part of the sporting events); and
  • the finishes are generally spartan.
Open spectator stand

Under specified circumstances (see ), an open spectator stand may be of Type C construction. The reason for this concession is that an open spectator stand generally has a low fire load, even though it may have a high population, particularly during an event; and is open at the front thereby not allowing the build up of smoke and heat.

Tier of seating—C1.7(b) and Figure C1.7

refers to a “tier of seating”. This describes the levels of seating in an open spectator stand. Figure C1.7 illustrates a single tiered open spectator stand, and a two tiered open spectator stand.

C1.8 Lightweight construction

(a)

Lightweight construction must comply with Specification C1.8 if it is used in a wall system—

(i)

that is required to have an FRL; or

(ii)

for a lift shaft, stair shaft or service shaft or an external wall bounding a public corridor including a non fire-isolated passageway or non fire-isolated ramp, in a spectator stand, sports stadium, cinema or theatre, railway station, bus station or airport terminal.

(b)

If lightweight construction is used for the fire-resisting covering of a steel column or the like, and if—

(i)

the covering is not in continuous contact with the column, then the void must be filled solid, to a height of not less than 1.2 m above the floor to prevent indenting; and

(ii)

the column is liable to be damaged from the movement of vehicles, materials or equipment, then the covering must be protected by steel or other suitable material.

Intent

To specify the requirements for the use of lightweight construction in:

  • circumstances which require walls with a fire-resistance level (FRL);
  • certain high use buildings; and
  • fire-resisting covering of steel columns or the like.
Definition of “lightweight construction”

Refer to for the definition of “lightweight construction”.

Figure C1.7

SINGLE TIERED AND TWO TIERED SEATING IN AN OPEN SPECTATOR STAND
guide_C17_2005.svg
Lightweight construction needs protection

Lightweight construction needs protection to preserve its integrity from mechanical damage in a fire or other situation where it may be particularly subject to risk of damage. This is because it is generally more susceptible to damage than other forms of wall construction, such as concrete (which does not contain soft materials) and masonry thicker than 70 mm.

Specification C1.8

To make sure lightweight construction performs correctly, states that it must comply with . This Specification sets down tests which such construction must satisfy.

Walls required to have an FRL—C1.8(a)(i)

Lightweight construction used in any wall system required to have a FRL must comply with (see ).

Walls not required to have an FRL—C1.8(a)(ii)

Lightweight construction must also comply with if it is used in a wall system which is not required to have a FRL, but is specifically listed in or in a building specifically listed in .

There is no requirement to comply with where lightweight construction is used for walls which:

  • are not listed in ;
  • are in buildings which are not listed in ; and
  • do not require fire-resistance levels.
Fire-resisting covering of steel columns—C1.8(b)

sets out the circumstances under which lightweight construction is permitted to be used as a fire-resisting covering for steel columns and the like.

C1.9 *  *  *  *  *

Blank clause

This clause has deliberately been left blank.

In BCA 1990, this provision related to Class 1 and Class 10 buildings, which are now covered in Volume Two of the BCA. This is the reason why has been left blank.

C1.10 Fire hazard properties

(a)

The fire hazard properties of the following linings, materials and assemblies in a Class 2 to 9 building must comply with Specification C1.10:

(i)

Floor linings and floor coverings.

(ii)

Wall linings and ceiling linings.

(iii)

Air-handling ductwork.

(iv)

Lift cars.

NSW C1.10(a)(v)

(v)

In Class 9b buildings used as a theatre, public hall or the like—

(A)

fixed seating in the audience area or auditorium; and

(B)

a proscenium curtain required by Specification H1.3.

(vi)

Escalators, moving walkways and non-required non fire-isolated stairways or pedestrian ramps subject to Specification D1.12.

(viii)

Attachments to floors, ceilings, internal walls and the internal linings of external walls.

(ix)

Other materials including insulation materials other than sarking-type materials.

NSW C1.10(b)

(b)

Paint or fire-retardant coatings must not be used to achieve compliance with the required fire hazard properties.

(c)

The requirements of (a) do not apply to a material or assembly if it is—

(i)

plaster, cement render, concrete, terrazzo, ceramic tile or the like; or

(iii)

a timber-framed window; or

(iv)

a solid timber handrail or skirting; or

(v)

a timber-faced solid-core door or timber-faced fire door; or

(vi)

an electrical switch, socket-outlet, cover plate or the like; or

(vii)

a material used for—

(A)

a roof insulating material applied in continuous contact with a substrate; or

(B)

an adhesive; or

(C)

a damp-proof course, flashing, caulking, sealing, ground moisture barrier, or the like; or

(viii)

a paint, varnish, lacquer or similar finish, other than nitro-cellulose lacquer; or

(ix)

a clear or translucent roof light of glass fibre-reinforced polyester if—

(A)

the roof in which it is installed forms part of a single storey building required to be Type C construction; and

(B)

the material is used as part of the roof covering; and

(C)

it is not closer than 1.5 m from another roof light of the same type; and

(D)

each roof light is not more than 14 m2 in area; and

(E)

the area of the roof lights per 70 m2 of roof surface is not more than 14 m2; or

(x)

a face plate or neck adaptor of supply and return air outlets of an air handling system; or

(xi)

a face plate or diffuser plate of light fitting and emergency exit signs and associated electrical wiring and electrical components; or

(xii)

a joinery unit, cupboard, shelving, or the like; or

NSW C1.10(c)(xiii)

(xiii)

an attached non-building fixture and fitting such as—

(A)

a curtain, blind, or similar decor, other than a proscenium curtain required by Specification H1.3; and

(B)

a whiteboard, window treatment or the like; or

(xiv)

timber treads, risers, landings and associated supporting framework installed in accordance with D2.25 where the Spread-of-Flame Index and the Smoke-Developed Index of the timber does not exceed 9 and 8 respectively; or

Vic C1.10(c)(xv)

(xv)

any other material that does not significantly increase the hazards of fire.

Intent

To stipulate the minimum fire hazard properties of materials susceptible to the effects of flame or heat.

Occupants must be able to evacuate

It is important that the spread of fire and the development of smoke be limited during a fire until building occupants have had time to evacuate. See .

lists the linings, materials and assemblies that must comply with .

Materials deemed to comply

and list materials that are not required to comply with . These materials are deemed to comply and accordingly no tests are required to prove that these materials meet the requirements of .

Fire retardant coatings not acceptable

Some paints have been designed to reduce flame spread on combustible materials. These paints, usually referred to as “fire retardant paint”, cannot be used to achieve any of the required fire hazard properties.

This material is unable to be used because of its susceptibility to damage.

does not prohibit the use of suitable impregnated materials that achieve the relevant fire hazard properties.

Exempted building parts and materials

to (xv) is a practical recognition that a number of building components and materials are unlikely to significantly contribute to the spread of fire and smoke, because of their size, construction, location and so on. The listed components and materials need not comply with .

grants an exemption to permit the use of glass reinforced polyester (GRP) in single storey buildings required to be of Type C construction.

The material is limited to GRP because it does not droop or drip when alight. Furthermore, limits the disposition and quantity of the GRP for use in the roof. This restriction is to reduce the likelihood of the rapid horizontal spread of fire over large sections of roofing.

Accordingly, for the exemption to be used there must be:

  • separation between individual roof lights made of this material;
  • a restricted area for each roof light; and
  • only a portion of the total roof sheeting made up of GRP.

GRP does not have the Spread-of-Flame Index and Smoke-Developed Index required by the Specification. However, the concession is provided because if GRP is installed in the prescribed manner, its use in single storey buildings of Type C construction will not materially increase the risk of spread of fire and smoke.

refers to elements within buildings such as joinery units, cupboards, shelving and the like which are typically attached to the building structure, however do not form part of the building structure. These elements are exempt as they do not form part of the structure and typically are not included within building works approval. Notwithstanding that these elements are often fixed to the building structure for stability, they are generally of low hazard and may be likened to any building furniture which is not subject to the fire hazard properties provisions.

Likewise, exempts certain types of non-building fixtures such as whiteboards, curtains and blinds, etc. Again, these elements are exempt as they do not form part of the structure and typically are not included within building works approval. It should be noted that not all such fixtures are exempt and reference needs to be made to to determine which elements must comply.

C1.11 Performance of external walls in fire

Concrete external walls that could collapse as complete panels (e.g. tilt-up and pre-cast concrete), in a building having a rise in storeys of not more than 2, must comply with Specification C1.11.

Intent

To minimise the risk of any concrete external wall collapsing outwards as a complete panel during a fire.

See the comments on CP5 for the reasons for ; and why only applies to a building having a rise in storeys of 1 or 2.

contains:

  • detailed solutions to avoid the potential collapse, as whole panels, of concrete external walls in a building with a rise in storeys of 2 or less; and
  • minimum design loads which panel connections must resist during a fire, to minimise the risk of panels collapsing outwards.

C1.12 Non-combustible materials

The following materials, though combustible or containing combustible fibres, may be used wherever a non-combustible material is required:

(a)

Plasterboard.

(b)

Perforated gypsum lath with a normal paper finish.

(c)

Fibrous-plaster sheet.

(d)

Fibre-reinforced cement sheeting.

(e)

Pre-finished metal sheeting having a combustible surface finish not exceeding 1 mm thickness and where the Spread-of-Flame Index of the product is not greater than 0.

(f)

Bonded laminated materials where—

(i)

each laminate is non-combustible; and

(ii)

each adhesive layer does not exceed 1 mm in thickness; and

(iii)

the total thickness of the adhesive layers does not exceed 2 mm; and

(iv)

the Spread-of-Flame Index and the Smoke-Developed Index of the laminated material as a whole does not exceed 0 and 3 respectively.

Intent

To permit the use of certain materials which are known to provide acceptable levels of fire safety.

lists materials deemed to be non-combustible. These materials may be used wherever a material is required to be non-combustible. In some instances the material may contain combustible components. The materials listed are not intended to apply to fire place hearths required by .

C1.13 Fire-protected timber: Concession

Fire-protected timber in a Class 2, 3 or 5 building may be used wherever an element is required to be non-combustible, provided—

(a)

the building is—

(i)

a separate building; or

(ii)

a part of a building—

(A)

which only occupies part of a storey, and is separated from the remaining part by a fire wall; or

(B)

which is located above or below a part not containing fire-protected timber and the floor between the adjoining parts is provided with an FRL not less than that prescribed for a fire wall for the lower storey; and

(b)

the building has an effective height of not more than 25 m; and

(c)

the building has a sprinkler system throughout complying with Specification E1.5; and

(d)

any insulation installed in the cavity of the timber building element required to have an FRL is non-combustible; and

(e)

cavity barriers are provided in accordance with Specification C1.13.

Intent

To permit fire-protected timber to be used where an element is required to be non-combustible.

provides requirements for when fire-protected timber can be used where an element is required to be non-combustible.

Limitations of the building

to has specific limitations for a building to use the concession for fire-protected timber.

requires a building to be a separate building, or a part of building to be separated from the remainder of the building. This includes separation via a fire wall where the part of the building only occupies part of a storey. Where the part of the building is below or above another classification, floor separation must be provided. A fire wall or floor required to have an FRL under cannot consist of fire-protected timber.

To use the concession, a height limitation in requires the building to have an effective height of not more than 25 m. also requires the building to be sprinkler protected in compliance with . This is for the purpose of the concession and is in addition to the sprinkler requirements of .

Construction requirements

and have specific construction requirements as part of the concession. Under , where insulation is installed in a fire-protected timber system, the insulation must be non-combustible.

requires cavity barriers for fire-protected timber to be provided in accordance with . A cavity barrier referred to in is a barrier/enclosure within, around or adjacent to the fire-protected timber to limit the spread of fire, smoke and hot gases in the event of a fire.