Part 9.2 Fire separation of external walls

An external wall of a Class 1 building, and any openings in that wall, must comply with 9.2.3 if the wall is less than—

1. 900 mm from an allotment boundary other than the boundary adjoining a road alignment or other public space; or
2. 1.8 m from another building on the same allotment other than a Class 10 building associated with the Class 1 building or a detached part of the same Class 1 building.

(1) The distance from any point on an external wall of a building to an allotment boundary or another building is the distance to that point measured along a line at right angles from the allotment boundary or external wall of the other building which intersects that point without being obstructed by a wall complying with 9.2.3.

(2) Where a wall within a specified distance is required to comply with 9.2.3, only that part of the wall (including any openings) within the specified distance need be constructed in that manner (see Figure 9.2.2a, Figure 9.2.2b and Figure 9.2.2c).

(3) Where the distance measured is between attached or detached buildings of different heights, the distance must be taken from the external wall with the highest elevation measured at right angles to a point that intersects the nearest part of a vertical projection above the adjacent building, excluding any eave overhang (see Figure 9.2.2d and Figure 9.2.2e).

(1) An external wall (including a gable) required to be fire-resisting (referred to in 9.2.1 or 9.2.4) must—

1. commence at the footings or ground slab, except where the external wall commences above a separating wall complying with 9.3.1 (see Figure 9.2.2e); and
2. extend to—
   1. the underside of a non-combustible roof covering, except that a wall may terminate not more than 200 mm from the underside of a non-combustible roof covering, where the area between the external wall and underside of the roof covering is sealed with a non-combustible fascia, gutter or flashing; or
   2. the underside of a non-combustible eaves lining (See Figures 9.2.3a and b); and
3. be constructed in accordance with (2).

(2) A wall required by (1) must—

1. have an FRL of not less than 60/60/60 when tested from the outside; or
2. be of masonry-veneer construction in which the external masonry veneer is not less than 90 mm thick; or
3. be of masonry construction not less than 90 mm thick.

(3) Openings in external walls required to be fire-resisting (referred to in 9.2.1 or 9.2.4) must be protected by—

1. non-openable fire windows or other construction with an FRL of not less than –/60/–; or
2. self-closing solid core doors not less than 35 mm thick.

(4) The requirements of (3) do not apply to a window in a non-habitable room that is located adjacent to and not less than 600 mm from the boundary of an adjoining allotment or 1.2 m from another building on the same allotment provided that—

1. in a bathroom, laundry or toilet, the opening has an area of not more than 1.2 m²; or
2. in a room other than one referred to in (a), the opening has an area of not more than 0.54 m² and—
   1. the window is steel-framed, there are no opening sashes and it is glazed in wired glass; or
   2. the opening is enclosed with translucent hollow glass blocks.

(5) Subfloor vents, roof vents, weepholes, control joints, construction joints and penetrations for pipes, conduits and the like need not comply with (3).

(1) A Class 1 building must be protected by a method in—

1. 9.2.5 where a Class 10a building is located between or adjacent to a Class 1 building and a boundary alignment that is not a boundary with a road alignment or other public space; or
2. 9.2.6 where a Class 10a building is located between or adjacent to a Class 1 building it is associated with and another building on the same allotment; or
3. 9.2.7 where two or more Class 10a buildings on the same allotment are located between and are associated with different Class 1 buildings.

(2) A Class 10a building must not significantly increase the risk of spread of fire between Class 2 to 9 buildings.

The following methods are acceptable for the protection of a Class 1 building where a Class 10a building is located between or adjacent to a Class 1 building and a boundary alignment that is not a boundary with a road alignment or other public space:

1. The Class 10a building is not less than 900 mm from the allotment boundary, other than the boundary adjoining a road alignment or other public space, as shown in Figure 9.2.5a.
2. An external wall of the Class 10a building which is less than 900 mm from an allotment boundary, other than the boundary adjoining a road alignment or other public space, complies with 9.2.3 as shown in Figure 9.2.5b.
3. An external wall of the Class 10a building, which is less than 900 mm from the Class 1 building, complies with 9.2.3 as shown in Figure 9.2.5c.
4. The Class 1 building is not less than 900 mm from the Class 10a building, as shown in Figure 9.2.5d.
5. An external wall of the Class 1 building, which is less than 900 mm from the Class 10a building, complies with 9.2.3, as shown in Figure 9.2.5e.
6. An external wall of the Class 10a building which is less than 900 mm from an allotment boundary other than the boundary adjoining a road alignment or other public space, complies with 9.2.3, as shown in Figure 9.2.5f.
7. An external wall of the Class 10a building, which is less than 900 mm from the external wall of the Class 1 building, complies with 9.2.3, as shown in Figure 9.2.5g.
8. An external wall of the Class 1 building, which is less than 900 mm from a Class 10a building that is situated less than 900 mm from an allotment boundary, complies with 9.2.3, as shown in Figure 9.2.5h.
9. The external wall of the Class 1 and Class 10a building which are less than 900 mm from an allotment boundary, other than the boundary adjoining a road alignment or other public space, complies with 9.2.3 as shown in Figure 9.2.5i.

The following methods are acceptable for the protection of a Class 1 building where a Class 10a building is located between or adjacent to a Class 1 building it is associated with and another building on the same allotment:

1. The Class 10a building is not less than 1.8 m from the other building, as shown in Figure 9.2.6a.
2. An external wall of the Class 10a building, which is less than 1.8 m from the other building, complies with 9.2.3, as shown in Figure 9.2.6b.
3. An external wall of the Class 10a building, which is less than 1.8 m from the Class 1 building, complies with 9.2.3, as shown in Figure 9.2.6c.
4. The Class 1 building is not less than 1.8 m from the Class 10a building, as shown in Figure 9.2.6d.
5. An external wall of the Class 1 building, which is less than 1.8 m from the Class 10a building, complies with 9.2.3, as shown in Figure 9.2.6e.
6. An external wall of the Class 10a building, which is less than 1.8 m from the external wall of the other building, complies with 9.2.3, as shown in Figure 9.2.6f.
7. An external wall of the Class 10a building, which is less than 1.8 m from the external wall of the Class 1 building, complies with 9.2.3, as shown in Figure 9.2.6g.
8. An external wall of the Class 1 and 10a building, which is less than 1.8 m from the external wall of the other building, complies with 9.2.3, as shown in Figure 9.2.6h.

The following methods are acceptable for the protection of a Class 1 building where two or more Class 10a buildings on the same allotment are located between and are associated with different Class 1 buildings:

1. Each Class 10a building must be separated from each other by a distance of not less than 1.8 m, as shown in Figure 9.2.7a.
2. Each Class 10a building must be separated from each other by external walls complying with 9.2.3, as shown in Figure 9.2.7b.
3. Each Class 10a building must be separated from each Class 1 building by a distance of not less than 900 mm, as shown in Figure 9.2.7c.
4. Each Class 10a building must be separated from each Class 1 building by external walls complying with 9.2.3, as shown in Figure 9.2.7d.
5. Each Class 10a building must be separated by a wall complying with 9.3.1, as shown in Figure 9.2.7e.
6. Each Class 10a building must be separated from each other by external walls complying with 9.2.3, as shown in Figure 9.2.7f.
7. Each Class 10a building must be separated from each Class 1 building by external walls complying with 9.2.3, as shown in Figure 9.2.7g.
8. Each Class 10a building must be separated by a wall complying with 9.3.1, as shown in Figure 9.2.7h.

A Class 10a carport is exempt from complying with 9.2.4(1) if—

1. it has two or more sides open and not less than one third of its perimeter open; and
2. for the purposes of (a), a side is considered to be open if the roof covering adjacent to that side is not less than 500 mm from another building or allotment boundary; and
3. it has a polycarbonate or non-combustible roof covering; and
4. any ceiling lining and wall cladding, including gables, is non-combustible (see Figure 9.2.8a); and
5. it does not provide direct vertical support to any part of the Class 1 building; and
6. in the case where it has a common roof structure with the Class 1 building and the carport does not have a ceiling (See Figure 9.2.8b), the opening between the top of the wall of the Class 1 building and the underside of the roof covering is infilled with—
   1. a non-combustible material; or
   2. construction clad with non-combustible material on the carport side.

(1) An encroachment is any construction—

1. between the external wall of the building and the allotment boundary other than a boundary adjoining a road or other public space; or
2. between the external walls of two buildings on the same allotment; or
3. between the external wall of the building and the vertical projection of the external wall of another building on the same allotment; or
4. that extends beyond the vertical projection of another building on the same allotment other than a building it is associated with.

(2) For the purposes of (1), an encroachment relates to any external wall of—

1. a Class 10a building required to comply with 9.2.4; or
2. a Class 1 building.

(3) Encroachments allowed within 900 mm of an allotment boundary or within 1.8 m of another building, or its vertical projection, on the same allotment are—

1. non-combustible fascias, gutters and downpipes; and
2. light fittings, electricity or gas meters, aerials or antennas; and
3. pergolas, sun blinds or water tanks (see Figure 9.2.9a); and
4. unroofed terraces, landings, steps and ramps, not more than 1 m in height.

(4) Encroachments allowed up to but not closer than 450 mm from an allotment boundary or up to but not closer than 900 mm from another building, or its vertical projection, on the same allotment or associated encroachments of another building on the same allotment are—

1. combustible fascias, gutters and downpipes (see Figure 9.2.9a, Figure 9.2.9b and Figure 9.2.9c); and
2. eaves with non-combustible roof cladding and non-combustible lining; and
3. flues, chimneys, pipes, domestic fuel tanks, cooling or heating appliances or other services.

(5) Encroachments allowed to project beyond the vertical projection of another building on the same allotment are non-combustible fascias, gutters and downpipes (see Figure 9.2.3b).

Combustible roof lights, skylights or the like installed in a roof or part of a roof required to have a non-combustible covering must—

1. have an aggregate area not more than 20% of the roof or part of the roof; and
2. be not less than—
   1. 900 mm from the allotment boundary other than the boundary adjoining a road alignment or other public space; and
   2. 1.8 m from any roof light or the like in another building on the allotment other than an associated building or a detached part of the same building (see Figure 9.2.10).