NCC 2022 Volume Two - Building Code of Australia Class 1 and 10 buildings
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H1
Part H1 StructurePart H1 Structure
Introduction to this Part
This Part focuses on safeguarding people from injury caused by structural failure, loss of amenity caused by structural behaviour (deflections, creep, vibration, settlement and the like), protection of other property from physical damage caused by structural failure and safeguarding people from injury that may be caused by failure of, or impact with, glazing.
Objectives
H1O1
Objective
2019: O2.1
H1O1
Objective
2019: O2.1
The Objective is to—
- safeguard people from injury caused by structural failure; and
- safeguard people from loss of amenity caused by structural behaviour; and
- protect other property from physical damage caused by structural failure; and
- safeguard people from injury that may be caused by failure of, or impact with, glazing.
Functional Statements
H1F1
Functional Statements
2019: F2.1
H1F1
Functional Statements
2019: F2.1
Performance Requirements
H1P1
Structural reliability and resistance
2019: P2.1.1
H1P1
Structural reliability and resistance
2019: P2.1.1
- perform adequately under all reasonably expected design actions; and
- withstand extreme or frequently repeated design actions; and
- be designed to sustain local damage, with the structural system as a remaining stable and not being damaged to an extent disproportionate to the original local damage; and
- avoid causing damage to other properties.
- permanent actions (dead loads); and
- imposed actions (live loads arising from occupancy and use); and
- wind action; and
- earthquake action; and
- snow action; and
- liquid pressure action; and
- ground water action; and
- rainwater action (including ponding action); and
- earth pressure action; and
- differential movement; and
- time dependent effects (including creep and shrinkage); and
- thermal effects; and
- ground movement caused by—
- swelling, shrinkage or freezing of the subsoil; and
- landslip or subsidence; and
- siteworks associated with the building or structure; and
- construction activity actions; and
- termite actions.
- known construction activities; and
- type of material; and
- characteristics of the site; and
- the degree of accuracy inherent in the methods used to assess the structural behaviour; and
- action effects arising from the differential settlement of foundations, and from restrained dimensional changes due to temperature, moisture, shrinkage, creep and similar effects.
- if broken on impact, will break in a way that is not likely to cause injury to people; and
- resists a reasonably foreseeable human impact without breaking; and
- is protected or marked in a way that will reduce the likelihood of human impact.
H1P2
Buildings in flood areas
2019: P2.1.2
H1P2
Buildings in flood areas
2019: P2.1.2
NCC Title
Buildings in flood areas
NCC State
QLD
NCC Variation Type
Deletion
NCC SPTC Current
Buildings in flood areas
NCC Notice
Building work in designated flood hazard areas is regulated by the Building Act 1975 and Development Code 3.5 - Construction of buildings in flood hazard areas.
NCC Title
Buildings in flood areas
NCC State
SA
NCC Variation Type
Deletion
NCC SPTC Current
Buildings in flood areas
NCC Notice
Part H1 does not apply in South Australia.
- flood actions; and
- elevation requirements; and
- foundation and footing requirements; and
- requirements for enclosures below the flood hazard level; and
- requirements for structural connections; and
- material requirements; and
- requirements for utilities; and
- requirements for occupant egress.
Limitations
H1P2 only applies to a Class 1 building.
NCC Blurbs
- if it serves a non-temporary Class 1 building, has a design life of at least 50 years; or
- if it serves a building not specified in (a), has a design life of at least 50 years or the specified design life of the building, whichever is the lesser; or
- is easily and readily accessible for replenishment or replacement and is capable of being replenished or replaced.
- be accessible to enable the installation, maintenance and inspection of the termite management measure to be carried out; and
- incorporate suitable measures to adequately minimise the risk of the termite management measure inadvertently being damaged, bridged or breached.
Explanatory information
QLD H1P3(1) requires a termite management measure in Queensland to have a design life of at least 50 years unless it is easily and readily accessible for replenishment or replacement and is capable of being replenished or replaced. In recognition that some buildings other than non-temporary Class 1 buildings may be designed to last less than 50 years, the option of the termite management measure having a design life at least equal to that specified for the building is given. If this option is used, the design life of the building should be agreed upon by all relevant stakeholders at the design stage and should form part of the documentation kept by the appropriate authority. It should not be assumed that the design life of 50 years in QLD H1P3(1)(a) and (b) applies to any other provisions of the BCA, unless stated.
An example of a termite management measure that may satisfy QLD H1P3(1)(c) is a chemical reticulation system beneath a concrete floor slab laid directly on the ground, provided that the system is easily and readily accessible for replenishment and is capable of being replenished.
An example of a termite management measure that may not satisfy QLD H1P3(1) for a non-temporary Class 1 building is a hand-sprayed chemical beneath a concrete floor slab laid directly on the ground if the chemical does not have a design life of at least 50 years. The concrete floor slab being laid directly on the ground would prevent the area beneath the slab from being easily and readily accessible for replenishment or replacement of the termite management measure.
An example of a termite management measure being inadvertently bridged or breached is when a person places a garden or mulch over the top of or above the level of a termite management measure enabling termites to bypass the measure.
NCC Title
Termite management measures
NCC State
QLD
NCC Variation Type
Insertion
NCC SPTC Current
Termite management measures
Building Classes
2,3,4,5,6,7a,7b,8,9a,9b,9c
Verification Methods
H1V1
Structural reliability
2019: V2.1.1
H1V1
Structural reliability
2019: V2.1.1
- the capacity reduction factor satisfies , where are capacity reduction factors for all relevant actions and must contain at least permanent (G), imposed (Q) and wind (W) actions; and
- the capacity reduction factors are calculated for target reliability indices for permanent action , for imposed action , for wind action in accordance with the equation: , where—
- ; and
-
, where—
- = ratio of mean resistance to nominal; and
- = ratio of mean action to nominal; and
- = correction factor for action; and
- = correction factor for resistance; and
- = coefficient of variation of the appropriate action as given in Table H1V1a; and
- = coefficient of variation of the resistance; and
- = appropriate load factor as given in AS/NZS 1170.0; and
- = capacity factor for the appropriate action; and
- the annual target reliability indices are established as follows:
- For situations where it is appropriate to compare with an equivalent Deemed-to-Satisfy product, a resistance model must be established for the equivalent Deemed-to-Satisfy product and must be calculated for the equivalent Deemed-to-Satisfy product in accordance with the equation given at (b).
- The target reliability indices thus established, must be not less than those given in Table H1V1b minus 0.5.
- For situations where it is not appropriate to compare with an equivalent Deemed-to-Satisfy product, the target reliability index must be as given in Table H1V1b.
Design action | Ratio of mean action to nominal | Coefficient of variation of the action |
---|---|---|
Permanent action | ||
Imposed action | ||
Wind action (Non-cyclonic) | ||
Wind action (Cyclonic) | ||
Snow action | ||
Earthquake action |
Type of action | Target reliability index β |
---|---|
Permanent action | 4.3 |
Imposed action | 4.0 |
Wind, snow and earthquake action | 3.7 |
Table Notes
- Table H1V1b is applicable for components that exhibit brittle failure similar to concrete as specified in AS 3600.
- For components with creep characteristics similar to timber as specified in AS 1720.1, the target reliability index for permanent action shall be increased to 5.0.
- The above target reliability indices are based on materials or systems that exhibit creep or brittle failure characteristics similar to timber and concrete.
- Table H1V1b may also be applicable to materials or systems that exhibit creep or brittle failure differently to steel, timber or concrete provided that the creep and/or brittle nature of the material or system are properly accounted for in the design model.
- The above target reliability indices are also applicable for materials or systems that exhibit ductile failure characteristics.
H1V2
Structural robustness
2019: V2.1.2
H1V2
Structural robustness
2019: V2.1.2
- any supporting column; or
- any beam supporting one or more columns; or
- any segment of a load bearing wall of length equal to the height of the wall.
Explanatory information
H1V2 is a means to verify structural robustness of a building or structure in order to meet the requirements of H1P1(1)(c). For further guidance, refer to the ABCB Handbook for Structural Robustness.
Deemed-to-Satisfy Provisions
H1D1
Deemed-to-Satisfy Provisions
New for 2022
H1D1
Deemed-to-Satisfy Provisions
New for 2022
H1D2
Structural provisions
2019: 3.0.1
H1D2
Structural provisions
2019: 3.0.1
H1D3
Site preparation
2019: 3.1.1, 3.1.2, 3.1.4
H1D3
Site preparation
2019: 3.1.1, 3.1.2, 3.1.4
Explanatory information: “Normal” site conditions
“Normal” site conditions relates to parameters such as—
- the site conditions not being significantly modified by the removal of previous buildings or other structures; and
- the moisture conditions on site being as a result of seasonal and climatic changes; and
- the site conditions not being subject to unusual moisture conditions caused by drains, dams, channels, ponds or tanks which are to be maintained or removed; and
- large trees have not been recently removed from the site in the area where the building is to be constructed; and
- other similar matters.
Further information regarding normal and abnormal site conditions can be found in AS 2870.
Explanatory information: Earth retaining structures
AS 4678 contains requirements for earth retaining structures between 800 mm and 15 m in height, and does not apply to structures which are founded in exceptional site conditions (e.g. landslips), are subjected to sustained cyclic loading or are used for the purposes of water-retaining (e.g. dams and reservoirs).
It should be noted that H1D3(2) is only one way of achieving compliance with H1P1. Other ways of complying include the following:
- The relevant structural design provisions referenced in H1D2.
- The relevant provisions of other Parts of the ABCB Housing Provisions relating to earth retaining structures.
- A Performance Solution that uses one of the other NCC Assessment Methods which verifies that compliance with H1P1 will be achieved.
Explanatory information: Termite risk management
The intent of these requirements is to provide for a termite management system that deters termites from gaining entry to a building via a concealed route. The installation of a termite management system will not stop termite activity from occurring on the site.
H1D4
Footings and slabs
2019: 3.2.0, 3.2.1
H1D4
Footings and slabs
2019: 3.2.0, 3.2.1
- One of the following:
- AS 2870.
- AS 3600.
- Subject to (2), Section 4 of the ABCB Housing Provisions.
NSW H1D4 Footings and slabs2019: 3.2.0, 3.2.1
Delete subclause H1D4(1) and insert H1D4(1) as follows:
- One of the following:
- AS 2870 except that for the purposes of Clause 5.3.3.1 of AS 2870 a damp-proofing membrane is required to be provided.
- AS 3600 except that barriers installed beneath slab on ground construction must have a high resistance to damage during construction.
- Subject to (2), Section 4 of the ABCB Housing Provisions.
- the footing is on a Class A, S or M site (classified in accordance with AS 2870) with a uniform bearing capacity; and
- any slab—
- is not more than 18 m long or wide; and
- does not contain permanent joints excluding construction joints; and
- is of a geometric shape containing only external right angles, other than a slab in (c); and
- any footing and slab in (b) has not more than one re-entrant corner; and
- the footing and slab are not constructed on soil classified as an aggressive soil type; and
- the structure supported by the footing does not contain—
- more than two trafficable floors; or
- a wall height exceeding 8 m, excluding any gable; and
- the footing does not support more than one concrete slab; and
- the building does not include wing walls or masonry arches unless they are detailed for movement in accordance with Cement Concrete and Aggregates Australia TN 61; and
- single leaf earth or stone masonry walls do not exceed 3 m in height; and
- the site is considered to be normal as defined in Part 3.2 of the ABCB Housing Provisions; and
- the site is not located in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
Explanatory information: Composite construction
Design requirements for other materials that may be used in combination with the above footing systems, including the use of heavy steel support beams and piled footings, etc. are described in H1D2 and in Section 2 of the ABCB Housing Provisions.
Explanatory information: Split level slab
For the purposes of H1D4(2)(e), split level slabs are considered as one slab. See Figure H1D4a.
Explanatory information: Geometric slab
For the purposes of H1D4(2)(b)(iii) and (c), a slab is considered geometric if it is square or rectangular and contains 4 external right angles as described in explanatory Figures H1D4b or H1D4c.
H1D5
Masonry
2019: 3.3.1-3.3.3, 3.3.5-3.3.6
H1D5
Masonry
2019: 3.3.1-3.3.3, 3.3.5-3.3.6
- AS 3700; or
- AS 4773.1 and AS 4773.2; or
-
Part 5.2 of the ABCB Housing Provisions provided—
- the building is located in an area with a wind class of not more than N3; and
- masonry veneer walls—
- the building site soil classification is A, S or M in accordance with AS 2870; and
- the framing that the masonry wall is tied to complies with H1D6; and
- the building is not constructed in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
- AS 3700; or
- AS 4773.1 and AS 4773.2; or
-
Part 5.3 of the ABCB Housing Provisions provided—
- the building is located in an area with a design wind speed of not more than N3; and
- cavity masonry walls—
- the building site soil classification is A, S or M in accordance with AS 2870; and
- the building is not constructed in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
- AS 3700; or
- AS 4773.1 and AS 4773.2; or
-
Part 5.4 of the ABCB Housing Provisions provided—
- the building is located in an area with a design wind speed of not more than N3; and
- single leaf unreinforced masonry walls—
- the building site soil classification is A, S or M in accordance with AS 2870; and
- the building is not constructed in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
- AS 3700, except—
- ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
- where clause 8.5.1 requires design as for unreinforced masonry in accordance with Section 7, the member must also be designed as unreinforced masonry in accordance with Table 10.3 and 4.1(a)(i)(C) of AS 3700; or
- AS 4773.1 and AS 4773.2.
- AS 3700, except—
- ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
- where clause 8.5.1 requires design as for unreinforced masonry in accordance with Section 7, the member must also be designed as unreinforced masonry in accordance with Table 10.3 and 4.1(a)(i)(C) of AS 3700.
- AS 4773.1 and AS 4773.2.
-
Part 5.5 of the ABCB Housing Provisions provided—
- the building is located in an area with a wind class of not more than N3; and
- isolated piers are constructed on footings and/or slabs that comply with H1D4; and
- masonry units comply with 5.6.2(4) of the ABCB Housing Provisions and have a minimum compressive strength of—
- 6.2 MPa for solid or cored units; or
- 15 MPa for hollow units; and
- the roof structure and any walls provide the required lateral bracing for the top of the isolated pier when determined in accordance with AS 3700, except—
- ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
- where clause 8.5.1 requires design as for unreinforced masonry in accordance with Section 7, the member must also be designed as unreinforced masonry in accordance with Table 10.3 and 4.1(a)(i)(C) of AS 3700; and
- the building site soil classification is A, S or M in accordance with AS 2870; and
- the building is not constructed in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
- AS 3700; or
- AS 4773.1 and AS 4773.2.
-
Part 5.6 of the ABCB Housing Provisions provided—
- the building is located in an area with a wind class of not more than N3; and
- the building is not constructed in an alpine area; and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.
Explanatory information: Composite construction
Design requirements for other materials that may be used in combination with masonry i.e. heavy steel support beams etc. are described in H1D2 and Section 2 of the ABCB Housing Provisions.
Explanatory information: AS 1170.4
There are certain limitations on the application to domestic building structures such as Class 1a and Class 1b buildings in Appendix A of AS 1170.4. These limitations include height, roof slope, etc. For additional information refer to Appendix A of AS 1170.4.
H1D6
Framing
2019: 3.4.0, 3.4.2-3.4.4
H1D6
Framing
2019: 3.4.0, 3.4.2-3.4.4
- Residential and low-rise steel framing:
- Design: NASH Standard ‘Residential and Low-Rise Steel Framing’ Part 1.
- Design solutions: NASH Standard ‘Residential and Low-Rise Steel Framing’ Part 2.
- Steel structures: AS 4100.
- Cold-formed steel structures: AS/NZS 4600.
- Design of timber structures: AS 1720.1.
- Design of nailplated timber roof trusses: AS 1720.5.
- Residential timber-framed construction – non-cyclonic areas: AS 1684.2 or AS 1684.4.
- Residential timber-framed construction – cyclonic areas: AS 1684.3.
- Installation of particleboard flooring: AS 1860.2.
QLD H1D6 Framing2019: 3.4.0, 3.4.2-3.4.4
Delete subclause H1D6(4) and insert H1D6(4) as follows:
- Design of timber structures: AS 1720.1.
- Design of nailplated timber roof trusses: AS 1720.5.
- Residential timber-framed construction – non-cyclonic areas: AS 1684.2.
- Residential timber-framed construction – cyclonic areas: AS 1684.3.
- Residential timber-framed construction – non-cyclonic areas (simplified): AS 1684.4.
- Installation of particleboard flooring: AS 1860.2.
- Timber species: In addition to sub-clauses (a) to (f) above, timber used for structural purposes must be a species scheduled for the appropriate use in Schedules A, B or C of Book 2 of the December 2017 version of the "Queensland Government, Department of Agriculture, Fisheries and Forestry - Construction timbers in Queensland, Book 1 and Book 2: Properties and specifications for satisfactory performance of construction timbers in Queensland - Class 1 and 10 buildings (Houses, carports, garages, greenhouses and sheds)".
- Steel structures: AS 4100.
- Cold-formed steel structures: AS/NZS 4600.
- For structural stability, strength and deflection, and subject to (6), Part 6.3 of the ABCB Housing Provisions.
- For corrosion protection, clause 6.3.9 of Part 6.3 of the ABCB Housing Provisions.
- the building is located in an area with a wind class of not more than N3; and
- the first dimension of steel sections is installed vertically; and
- all loads are evenly distributed (unless otherwise noted or allowed for); and
- the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements; and
- the structural steel members are not subject to snow loads; and
- the structural steel members are in buildings within geometric limits set out in clause 1.2 of AS 4055.
- Structural software used in computer aided design of a building or structure, that uses design criteria based on the Deemed-to-Satisfy Provisions of Section H, including its referenced documents, for the design of steel or timber trussed roof and floor systems and framed building systems, must comply with the ABCB Protocol for Structural Software.
- Structural software referred to in (a) can only be used for buildings within the following geometric limits:
- The distance from ground level to the underside of eaves must not exceed 6 m.
- The distance from ground level to the highest point of the roof, neglecting chimneys, must not exceed 8.5 m.
- The building width including roofed verandahs, excluding eaves, must not exceed 16 m.
- The building length must not exceed five times the building width.
- The roof pitch must not exceed 35 degrees.
- The requirements of (a) do not apply to design software for individual frame members such as electronic tables similar to those provided in—
- AS 1684; or
- NASH Standard – Residential and Low-Rise Steel Framing, Part 2.
Design member | Member 1 | Member 2 |
---|---|---|
Effective load width | 0.5 x Span 1 | 0.5 x (Span 1 + Span 2) |
Design Member | Member 1 | Member 2 | Member 3 |
---|---|---|---|
Effective load width | 0.4 x Span 1 | 0.6 x (Span 1 + Span 2) | 0.5 x (Span 2) + Span 3 |
Table Notes
The length of Span 3 must not be more than 0.5 x Span 2.
Explanatory information
For the purposes of H1D6(2), design requirements for other materials used in combination with steel or timber framing, including the use of concrete floors, structural steel support beams, etc. are described in the following locations within the ABCB Housing Provisions:
- Section 2 for structural provisions.
- Part 6.3 for structural steel members.
The weight of roof or ceiling insulation, particularly if additional ceiling insulation is used for compliance with the energy efficiency provisions, needs to be considered in the selection of plasterboard, plasterboard fixings and building framing.
For the purposes of H1D6(3) and (4):
- Information on design wind speeds for particular areas may be available from the appropriate authority.
- A map indicating cyclonic regions of Australia is contained in Part 2.2.
- There are certain limitations on the application to domestic structures such as Class 1a and 1b buildings in Appendix A of AS 1170.4. These limitations include building height, roof slope, etc. For additional information refer to Appendix A of AS 1170.4.
H1D6(7) does not apply where a software package simply eliminates manual calculations and the process of the package requires identical methodology as that undertaken manually, e.g. AS 1684 span tables and bracing calculations.
The application of Part 6.3 of the ABCB Housing Provisions requires all loads to be distributed evenly unless they are noted otherwise or allowed for within the construction and placement of relevant building elements. Part 6.3 of the ABCB Housing Provisions allows for point loads to be applied to strutting beams only if the loads are located within the middle third of the beam’s span. In any other case, designs should be carried out in accordance with either H1D6(5)(a) or (b), or by a suitably qualified practitioner.
Explanatory information: Explanation of first dimension of steel section installed vertically
H1D6(6) provides that Part 6.3 of the ABCB Housing Provisions satisfies Performance Requirement H1P1 with respect to structural stability, strength and deflection if the ‘first dimension’ of a steel section is installed vertically.
For example, a 150 x 90 x 8 UA is used as a structural steel member (lintel) to support masonry over an opening.
The “first dimension” designated is 150 mm (b1) and is the vertical leg that resists bending loads over the width of the opening. This leg must be installed in the vertical plane.
The 90 mm (b2) designation refers to the horizontal leg that rests under the masonry elements and transfers direct loads to the extremities of the opening while the 8 mm (t) designation refers to the thickness of the steel section.
A 150 x 90 x 8 UA is designated as follows:
- 150 = leg length (b1)
- 90 = leg length (b2)
- 8 = thickness (t)
These designations are depicted in Explanatory Figure H1D6.
H1D7
Roof and wall cladding
2019: 3.5, 3.5.1-3.5.5
H1D7
Roof and wall cladding
2019: 3.5, 3.5.1-3.5.5
NCC Blurbs
- Metal roofing:
- AS 1562.1; and
- in wind regions B, C and D in accordance with Figure 2.2.3 in Section 2 of the ABCB Housing Provisions (cyclonic areas), metal roof assemblies, their connections and immediate supporting members must be capable of remaining in position notwithstanding any permanent distortion, fracture or damage that might occur in the sheet or fastenings under the pressure sequences A to G defined in Table H1D7.
- Plastic sheet roofing: AS 1562.3.
- Metal sheet roofing: Part 7.2 of the ABCB Housing Provisions, provided the building is located in an area with a wind class of not more than N3.
- Terracotta, fibre-cement and timber slates and shingles: AS 4597.
- For roof tiles—
- AS 2050; or
-
Part 7.3 of the ABCB Housing Provisions, provided—
- the building is located in an area with a wind class of not more than N3; and
- the roof tiles comply with AS 2049; and
- the roof has a pitch of not less than 15 degrees and not more than 35 degrees.
- for autoclaved aerated concrete wall cladding, AS 5146.1; or
- for wall cladding, Part 7.5 of the ABCB Housing Provisions.
Sequence | Number of cycles | Load |
---|---|---|
A | 4500 | 0 to 0.45 Pt |
B | 600 | 0 to 0.6 Pt |
C | 80 | 0 to 0.8 Pt |
D | 1 | 0 to 1.0 Pt |
E | 80 | 0 to 0.8 Pt |
F | 600 | 0 to 0.6 Pt |
G | 4500 | 0 to 0.45 Pt |
Table Notes
- Pt is the ultimate limit state wind pressure on internal and external surfaces as determined in accordance with AS/NZS 1170.2, modified by an appropriate factor for variability, as determined in accordance with Table B1 of AS/NZS 1170.0.
- The rate of load cycling must be less than 3 Hz.
- The single load cycle (sequence D) must be held for a maximum of 10 seconds.
Explanatory information
The requirements of H1D7(2)(a)(ii) must be read in conjunction with the provisions of AS/NZS 1170.2. The ABCB commissioned research to establish a nationally consistent testing regime for metal roof cladding assemblies in cyclonic areas. The results of this research are contained in H1D7(2)(a)(ii).
Low cycle fatigue cracking of metal roof cladding elements during tropical cyclones is a complex process where small changes in load, geometry or material properties can significantly affect the fatigue performance of the cladding system (includes immediate supports, fixings and cladding). The consequences of failure of an element can quickly lead to more elements progressively failing. These failed elements become wind driven debris and so pose a threat to people and other structures as potential missiles.
If a system does not successfully resist the fatigue loading sequence in Table H1D7, it does not comply. The test section consists of cladding elements, fastenings and immediate supporting members assembled together in a manner identical to those parts of the particular roof which the test section is intended to replicate.
Explanatory information
In Western Australia state variations apply to wind Regions B and D, this includes wind region B2 as referenced in AS/NZS 1170.2.
The state variation for wind region B or B2 will ensure that designers consider the combination of peak external pressures and increased internal pressures in design of buildings and use a cyclonic (C) classification instead of non-cyclonic (N) classification. The definition of design wind speed is varied in WA Schedule 1 to identify that wind Region B is a C classification in Western Australia. Other changes have also been made to reflect this.
In addition to a variation to clause H1D7 of NCC Volume Two, and clauses 2.2.3 and 2.2.4 of the ABCB Housing Provisions Standard - a variation is made to the application of AS/NZS 1170.2 and AS 4055 (when used as a primary referenced document, secondary or subsequent referenced document). Refer to the WA Schedule 2 and WA Part 2.3.
The state variation for wind region D applies only to those parts of region D located north of the Tropic of Capricorn. The 2021 edition of AS/NZS 1170.2 includes a reduction in design wind speeds for wind region D. The variation will retain similar design wind speeds for wind region D as the 2011 edition of AS/NZS 1170.2 previously referenced in the National Construction Code.
NCC Title
Roof and wall cladding
NCC State
WA
NCC Variation Type
Replacement
NCC SPTC Current
Roof and wall cladding
- Metal roofing:
- AS 1562.1; and
- in wind regions C and D in accordance with Figure 2.2.3 in Section 2 of the ABCB Housing Provisions (cyclonic areas), metal roof assemblies, their connections and immediate supporting members must be capable of remaining in position notwithstanding any permanent distortion, fracture or damage that might occur in the sheet or fastenings under the pressure sequences A to G defined in Table H1D7.
- Plastic sheet roofing: AS 1562.3.
- Metal sheet roofing: Part 7.2 of the ABCB Housing Provisions, provided the building is located in an area with a wind class of not more than N3.
- Terracotta, fibre-cement and timber slates and shingles: AS 4597.
- For roof tiles—
- AS 2050; or
-
Part 7.3 of the ABCB Housing Provisions, provided—
- the building is located in an area with a wind class of not more than N3; and
- the roof tiles comply with AS 2049; and
- the roof has a pitch of not less than 15 degrees and not more than 35 degrees.
- for autoclaved aerated concrete wall cladding, AS 5146.1; or
- for wall cladding, Part 7.5 of the ABCB Housing Provisions.
Sequence | Number of cycles | Load |
---|---|---|
A | 4500 | 0 to 0.45 Pt |
B | 600 | 0 to 0.6 Pt |
C | 80 | 0 to 0.8 Pt |
D | 1 | 0 to 1.0 Pt |
E | 80 | 0 to 0.8 Pt |
F | 600 | 0 to 0.6 Pt |
G | 4500 | 0 to 0.45 Pt |
Table Notes
- Pt is the ultimate limit state wind pressure on internal and external surfaces as determined in accordance with AS/NZS 1170.2, modified by an appropriate factor for variability, as determined in accordance with Table B1 of AS/NZS 1170.0.
- The rate of load cycling must be less than 3 Hz.
- The single load cycle (sequence D) must be held for a maximum of 10 seconds.
Explanatory information
The requirements of H1D7(2)(a)(ii) must be read in conjunction with the provisions of AS/NZS 1170.2. The ABCB commissioned research to establish a nationally consistent testing regime for metal roof cladding assemblies in cyclonic areas. The results of this research are contained in H1D7(2)(a)(ii).
Low cycle fatigue cracking of metal roof cladding elements during tropical cyclones is a complex process where small changes in load, geometry or material properties can significantly affect the fatigue performance of the cladding system (includes immediate supports, fixings and cladding). The consequences of failure of an element can quickly lead to more elements progressively failing. These failed elements become wind driven debris and so pose a threat to people and other structures as potential missiles.
If a system does not successfully resist the fatigue loading sequence in Table H1D7, it does not comply. The test section consists of cladding elements, fastenings and immediate supporting members assembled together in a manner identical to those parts of the particular roof which the test section is intended to replicate.
H1D8
Glazing
2019: 3.6
H1D8
Glazing
2019: 3.6
- designed and constructed in accordance with AS 2047 for glazed assemblies in an external wall including—
- installed such that they comply with—
- AS 2047; and
-
Part 8.2 of the ABCB Housing Provisions, provided that they are—
- in buildings that are within the geometric limits set out in clause 1.2 of AS 4055; and
- located in an area with a wind class of not more than N3.
- complies with Part 8.3 of the ABCB Housing Provisions; or
- is designed and constructed in accordance with AS 1288 for all glazed assemblies not covered by (1) and the following glazed assemblies:
- All glazed assemblies not in an external wall.
- Revolving doors.
- Fixed louvres.
- Skylights, roof lights and windows other than in the vertical plane.
- Sliding and swinging doors without a frame.
- Windows constructed on-site and architectural one-off windows, which are not design tested in accordance with AS 2047.
- Second-hand windows, re-used windows and recycled windows.
- Heritage windows.
- Glazing used in balustrades and overhead glazing.
Explanatory information: AS 2047
- AS 2047 specifies requirements for the design, testing and manufacture of windows. The reference to windows in AS 2047 includes certain types of louvres and glazed doors that may be sliding, swinging, French or bi-fold doors.
- AS 2047 does not cover assemblies that are internal or revolving doors, fixed louvres, skylights, rooflights and windows not installed in the vertical plane, windows in greenhouses or horticultural buildings, frameless sliding or swinging doors, windows constructed on site, one-off untested architectural designed windows, second-hand, recycled or reused windows and heritage windows defined by relevant State and Territory authorities.
Explanatory information: AS 1288
In relation to building work covered by NCC Volume Two and the ABCB Housing Provisions, AS 1288 does not cover the selection and installation of glass for windows and doors in heritage buildings, restoration or repairs to leadlights, glass blocks, bricks or pavers.
Explanatory information: AS 4055
Clause 1.2 of AS 4055 sets out geometric limitations that include the following:
- The distance from the ground level adjacent to the building to the underside of eaves is not to exceed 6.0 m.
- The distance from the ground level of the building to the highest point of the roof, excluding chimneys is not to exceed 8.5 m.
- The width of the building, including verandas, but excluding eaves, is not to exceed 16.0 m.
- The length of the building is not to exceed five times its width.
- The roof pitch is not to exceed 35°.
H1D9
Earthquake areas
2019: 3.10.2
H1D9
Earthquake areas
2019: 3.10.2
Performance RequirementH1P1 for Class 1 and 10 buildings constructed in areas subject to seismic activity is satisfied if the building is constructed in accordance with Section 2 of the ABCB Housing Provisions.
Explanatory information
- Most domestic structures are not required to be specifically designed for earthquakes.
- There are certain limitations on the application to domestic structures such as Class 1a and 1b buildings in Appendix A of AS 1170.4. These limitations include building height, roof slope, etc. For additional information refer to Appendix A of AS 1170.4.
H1D10
Flood hazard areas
2019: 3.10.3
H1D10
Flood hazard areas
2019: 3.10.3
NCC Title
Flood hazard areas
NCC State
QLD
NCC Variation Type
Deletion
NCC SPTC Current
Flood hazard areas
NCC Notice
Building work in designated flood hazard areas is regulated by the Building Act 1975 and the Queensland Development Code 3.5 - Construction of buildings in flood hazard areas.
NCC Blurbs
NCC Title
Flood hazard areas
NCC State
VIC
NCC Variation Type
Replacement
NCC SPTC Current
Flood hazard areas
Building Classes
2,3,4,5,6,7a,7b,8,9a,9b,9c,10a,10b,10c
Performance RequirementH1P2 for a Class 1 building constructed in a flood hazard area is satisfied if the building is constructed in accordance with the ABCB Standard for Construction of Buildings in Flood Hazard Areas.
H1D11
Attachment of framed decks and balconies to external walls of buildings using a waling plate
2019: 3.10.6.1
H1D11
Attachment of framed decks and balconies to external walls of buildings using a waling plate
2019: 3.10.6.1
Performance RequirementH1P1 is satisfied for the attachment of a deck or balcony to an external wall if it complies with Part 12.3 of the ABCB Housing Provisions, provided—
- the deck or balcony is not located in an alpine area; and
- the height of the deck or balcony is not more than 3 m measured from the uppermost finished floor surface of the deck or balcony at any point to the top of any supporting footing; and
- the waling plate does not support—
- more than one floor; or
- loadbearing or non-loadbearing walls; or
- roof loads; and
- the deck or balcony does not cantilever off the external wall; and
- the total imposed load on the deck or balcony does not exceed 2 kPa; and
- the deck or balcony framing including member sizes, spans and spacing, bracing for racking and shear forces, fixings and structural supports complies with H1D2; and
- steel framing constructed in accordance with H1D6(3); and
- timber framing is constructed in accordance with H1D6(4); and
- the external wall supporting the deck or balcony is constructed of—
- the external wall referred to in (i) must be continuous from the upper most surface of the deck or balcony to the supporting footing and contain no openings or lintels below the deck or balcony; and
- the waling plate is fixed to the external wall in accordance with clause 12.3.2 of the ABCB Housing Provisions and attached by—
- fixing the waling plate through wall cladding complying with H1D7(4) or H1D7(5), provided the cladding is directly fixed to the external wall; or
- removing parts of the wall cladding so that the waling plate is directly fixed to the external wall, with—
- the junction of the waling plate and the external wall flashed in accordance with clause 12.3.3 of the ABCB Housing Provisions; and
- the cladding restored to its original strength by installing blocking supports as necessary on completion of installation; and
- the deck or balcony is braced to prevent lateral movement in accordance with clause 12.3.4 of the ABCB Housing Provisions.
Explanatory information
A 2 kPa imposed load is commensurate with domestic and residential activities associated with Class 1 buildings (e.g. dwellings with limited occupancy and restricted public access) and is not appropriate for applications where the deck or balcony supports heavy equipment, spa/bathing pools or circumstances where the deck or balcony is intended for community access (e.g. applications with a mid-high occupancy and possibility of public access).
If the design live load of the deck or balcony is more than 2 kPa, the framing members of the deck or balcony must be designed by a professional engineer or other appropriately qualified person in accordance with the relevant structural design manuals in Part 2.2 of the ABCB Housing Provisions.
H1D11(k)(ii) requires consideration to be given to restoring cladding, weatherproofing and structural properties. Other considerations include restoring the appropriate sound and thermal insulation, and the capacity to maintain an FRL where required.
H1D11 describes the circumstances under which the methods of attachment described in this Part are deemed appropriate.
Where a deck or balcony is constructed outside the conditions listed in H1D11, e.g. attachment to a masonry veneer wall, the method of attachment to the building or structure must be designed by a professional engineer or other appropriately qualified person in accordance with the relevant structural design manuals in Part 2.2 of the ABCB Housing Provisions. Such a design will need to consider the suitability of the wall to withstand the loads imposed by the deck or balcony, and the capacity of the connections.
Examples of external wall construction that are outside the application of H1D11 include a masonry external wall that is not fully core-filled, cavity masonry and masonry veneer construction where fasteners may be subject to withdrawal.
An alternative to attaching a deck or balcony directly to an external wall includes providing supporting piers, posts or columns or the like parallel to the wall line or at right angles to the wall.
H1D12
Piled footings
3.2.0
H1D12
Piled footings
3.2.0
Performance RequirementH1P1 is satisfied for piled footings if they are designed and installed in accordance with AS 2159.