Part H1 Structure

The Objective is to—

1. safeguard people from injury caused by structural failure; and
2. safeguard people from loss of amenity caused by structural behaviour; and
3. protect other property from physical damage caused by structural failure; and
4. safeguard people from injury that may be caused by failure of, or impact with, glazing.

(1) A building or structure is to withstand the combination of loads and other actions to which it may be reasonably subjected.

(2) Glazing is to be installed in a building to avoid undue risk of injury to people.

(1) By resisting the actions to which it may reasonably be expected to be subjected, a building or structure, during construction and use, with appropriate degrees of reliability, must—

1. perform adequately under all reasonably expected design actions; and
2. withstand extreme or frequently repeated design actions; and
3. 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
4. avoid causing damage to other properties.

(2) The actions to be considered to satisfy (1) include but are not limited to—

1. permanent actions (dead loads); and
2. imposed actions (live loads arising from occupancy and use); and
3. wind action; and
4. earthquake action; and
5. snow action; and
6. liquid pressure action; and
7. ground water action; and
8. rainwater action (including ponding action); and
9. earth pressure action; and
10. differential movement; and
11. time dependent effects (including creep and shrinkage); and
12. thermal effects; and
13. ground movement caused by—
    1. swelling, shrinkage or freezing of the subsoil; and
    2. landslip or subsidence; and
    3. siteworks associated with the building or structure; and
14. construction activity actions; and
15. termite actions.

(3) The structural resistance of materials and forms of construction must be determined using five percentile characteristic material properties with appropriate allowance for—

1. known construction activities; and
2. type of material; and
3. characteristics of the site; and
4. the degree of accuracy inherent in the methods used to assess the structural behaviour; and
5. action effects arising from the differential settlement of foundations, and from restrained dimensional changes due to temperature, moisture, shrinkage, creep and similar effects.

(4) Glass installations that are at risk of being subjected to human impact must have glazing that—

1. if broken on impact, will break in a way that is not likely to cause injury to people; and
2. resists a reasonably foreseeable human impact without breaking; and
3. is protected or marked in a way that will reduce the likelihood of human impact.

(1) A building in a flood hazard area must be designed and constructed, to the degree necessary, to resist flotation, collapse or significant permanent movement resulting from the action of hydrostatic, hydrodynamic, erosion and scour, wind and other actions during the defined flood event.

(2) The actions and requirements to be considered to satisfy (1) include but are not limited to—

1. flood actions; and
2. elevation requirements; and
3. foundation and footing requirements; and
4. requirements for enclosures below the flood hazard level; and
5. requirements for structural connections; and
6. material requirements; and
7. requirements for utilities; and
8. requirements for occupant egress.

(1) This Verification Method is only applicable to components with a resistance coefficient of variation of at least 10% and not more than 40%.

(2) For components with a calculated resistance coefficient of variation value less than 10%, then a minimum value of 10% should be used.

(3) Compliance with H1P1(1), (2) and (3) is verified for the design of a structural component for strength when—

1. the capacity reduction factor

   $\varphi$

   satisfies

   $\varphi \le Average({\varphi }_G,{\varphi }_Q,{\varphi }_{W,\mathrm{...}})$

   , where

   ${\varphi }_G,{\varphi }_Q,{\varphi }_{W,\mathrm{...}}$

   are capacity reduction factors for all relevant actions and must contain at least permanent (G), imposed (Q) and wind (W) actions; and
2. the capacity reduction factors

   ${\varphi }_G,{\varphi }_Q,{\varphi }_{W,\mathrm{...}}$

   are calculated for target reliability indices for permanent action

   ${\beta }_{TG}$

   , for imposed action

   ${\beta }_{TQ}$

   , for wind action

   ${\beta }_{TW},\mathrm{...}$

   in accordance with the equation:

   $\beta =\ln \left[\left(\frac{\overline{R}}{\overline{S}}\right)\sqrt{\frac{C_S}{C_R}}\right]/\sqrt{\ln (C_R.C_S)}$

   , where—

   1. $\left(\frac{\overline{R}}{\overline{S}}\right)=\frac{\left(\frac{\gamma }{\varphi }\right)}{\left(\frac{\overline{S}}{S_N}\right)}\left(\frac{\overline{R}}{R_N}\right)$

      ; and

   2. $\begin{array}{l}{C}_R=1+V_R^2\\ C_S=1+V_S^2 \end{array}$

      , where—

      1. $\frac{\overline{R}}{R_N}$

         = ratio of mean resistance to nominal; and

      2. $\frac{\overline{S}}{S_N}$

         = ratio of mean action to nominal; and

      3. $C_S$

         = correction factor for action; and

      4. $C_R$

         = correction factor for resistance; and

      5. $VS$

         = coefficient of variation of the appropriate action as given in Table H1V1a; and

      6. $VR$

         = coefficient of variation of the resistance; and

      7. $\gamma$

         = appropriate load factor as given in AS/NZS 1170.0; and

      8. $\varphi$

         = capacity factor for the appropriate action; and
3. the annual target reliability indices

   ${\beta }_{TG},{\beta }_{TQ},{\beta }_{TW},\mathrm{...}$

   are established as follows:
   1. 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

      ${\beta }_{TG},{\beta }_{TQ},{\beta }_{TW}$

      must be calculated for the equivalent Deemed-to-Satisfy product in accordance with the equation given at (b).
   2. The target reliability indices

      ${\beta }_{TG},{\beta }_{TQ},{\beta }_{TW},\mathrm{...}$

      thus established, must be not less than those given in Table H1V1b minus 0.5.
   3. For situations where it is not appropriate to compare with an equivalent Deemed-to-Satisfy product, the target reliability index

      $\beta$

      must be as given in Table H1V1b.

(4) The resistance model for the component must be established by taking into account variability due to material properties, fabrication and construction processes and structural modelling.

(1) Compliance with H1P1(1)(c) is verified for structural robustness if (2) and (3) are complied with.

(2) The structure is assessed such that the building remains stable and the resulting collapse does not extend further than the immediately adjacent storeys upon the notional removal in isolation of—

1. any supporting column; or
2. any beam supporting one or more columns; or
3. any segment of a load bearing wall of length equal to the height of the wall.

(3) It is demonstrated that if a supporting structural component is relied upon to carry more than 25% of the total structure, a systematic risk assessment of the building is undertaken and critical high risk components are identified and designed to cope with the identified hazard or protective measures chosen to minimise the risk.

(1) Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements H1P1 and H1P2 are satisfied by complying with H1D2 to H1D11.

(2) Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable.

A Class 1 or Class 10 building must be constructed in accordance with—

1. Section 2 of the ABCB Housing Provisions; or
2. the relevant provisions of H1D3 to H1D12; or
3. any combination thereof.

(1) Performance RequirementH1P1 is satisfied for earthworks associated with the construction of a building or structure if they are in accordance with Part 3.2 of the ABCB Housing Provisions, provided that the site is classified as A, S, M, H or E in accordance with 4.2.2 of the ABCB Housing Provisions and the work is undertaken in normal site conditions.

(2) Performance RequirementH1P1 is satisfied for an earth retaining structure associated with the construction of a building or structure if it is designed and constructed in accordance with AS 4678.

(2) Section 4 of the ABCB Housing Provisions may only be used where—

1. the footing is on a Class A, S or M site (classified in accordance with AS 2870) with a uniform bearing capacity; and
2. any slab—
   1. is not more than 18 m long or wide; and
   2. does not contain permanent joints excluding construction joints; and
   3. is of a geometric shape containing only external right angles, other than a slab in (c); and
3. any footing and slab in (b) has not more than one re-entrant corner; and
4. the footing and slab are not constructed on soil classified as an aggressive soil type; and
5. the structure supported by the footing does not contain—
   1. more than two trafficable floors; or
   2. a wall height exceeding 8 m, excluding any gable; and
6. the footing does not support more than one concrete slab; and
7. 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
8. single leaf earth or stone masonry walls do not exceed 3 m in height; and
9. the site is considered to be normal as defined in Part 3.2 of the ABCB Housing Provisions; and
10. the site is not located in an alpine area; and
11. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(1) Performance RequirementH1P1 is satisfied for masonry veneer if it is designed and constructed in accordance with—

1. AS 3700; or
2. AS 4773.1 and AS 4773.2; or
3. Part 5.2 of the ABCB Housing Provisions provided—
   1. the building is located in an area with a wind class of not more than N3; and
   2. masonry veneer walls—
      1. are constructed on footings and/or slabs that comply with H1D4; and
      2. comply with Part 5.6 using components that comply with Part 5.7 of the ABCB Housing Provisions; and
   3. the building site soil classification is A, S or M in accordance with AS 2870; and
   4. the framing that the masonry wall is tied to complies with H1D6; and
   5. the building is not constructed in an alpine area; and
   6. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(2) Performance RequirementH1P1 is satisfied for cavity brick unreinforced masonry if it is designed and constructed in accordance with:

1. AS 3700; or
2. AS 4773.1 and AS 4773.2; or
3. Part 5.3 of the ABCB Housing Provisions provided—
   1. the building is located in an area with a design wind speed of not more than N3; and
   2. cavity masonry walls—
      1. are constructed on footings and/or slabs that comply with H1D4; and
      2. comply with Part 5.6 using components that comply with Part 5.7 of the ABCB Housing Provisions; and
   3. the building site soil classification is A, S or M in accordance with AS 2870; and
   4. the building is not constructed in an alpine area; and
   5. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(3) Performance RequirementH1P1 is satisfied for single leaf unreinforced masonry if it is designed and constructed in accordance with:

1. AS 3700; or
2. AS 4773.1 and AS 4773.2; or
3. Part 5.4 of the ABCB Housing Provisions provided—
   1. the building is located in an area with a design wind speed of not more than N3; and
   2. single leaf unreinforced masonry walls—
      1. are constructed on footings and/or slabs that comply with H1D4; and
      2. comply with Part 5.6 using components that comply with Part 5.7 of the ABCB Housing Provisions; and
   3. the building site soil classification is A, S or M in accordance with AS 2870; and
   4. the building is not constructed in an alpine area; and
   5. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(4) Performance RequirementH1P1 is satisfied for reinforced masonry if it is designed and constructed in accordance with:

1. AS 3700, except—
   1. ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
   2. 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
2. AS 4773.1 and AS 4773.2.

(5) Performance RequirementH1P1 is satisfied for an isolated masonry pier system if it is designed and constructed in accordance with one of the following, as appropriate:

1. AS 3700, except—
   1. ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
   2. 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.
2. AS 4773.1 and AS 4773.2.
3. Part 5.5 of the ABCB Housing Provisions provided—
   1. the building is located in an area with a wind class of not more than N3; and
   2. isolated piers are constructed on footings and/or slabs that comply with H1D4; and
   3. masonry units comply with 5.6.2(4) of the ABCB Housing Provisions and have a minimum compressive strength of—
      1. 6.2 MPa for solid or cored units; or
      2. 15 MPa for hollow units; and
   4. 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—
      1. ‘(for piers—isolated or engaged)’ is removed from clause 8.5.1(d); and
      2. 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
   5. the building site soil classification is A, S or M in accordance with AS 2870; and
   6. the building is not constructed in an alpine area; and
   7. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(6) Performance RequirementH1P1 is satisfied for masonry accessories if they are constructed and installed in accordance with:

1. AS 3700; or
2. AS 4773.1 and AS 4773.2.
3. Part 5.6 of the ABCB Housing Provisions provided—
   1. the building is located in an area with a wind class of not more than N3; and
   2. the building is not constructed in an alpine area; and
   3. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements.

(1) Diagrams depicting framing members and associated terminology used to describe them are set out in Figures H1D6c, H1D6d and H1D6e, and in most cases are applicable for both steel and timber frame members.

(2) Terminology and spacing for structural steel members are set out in Tables H1D6a and H1D6b, and Figures H1D6a, H1D6b and H1D6f.

(3) Performance RequirementH1P1 is satisfied for steel framing if it is designed and constructed in accordance with one of the following:

1. Residential and low-rise steel framing:
   1. Design: NASH Standard ‘Residential and Low-Rise Steel Framing’ Part 1.
   2. Design solutions: NASH Standard ‘Residential and Low-Rise Steel Framing’ Part 2.
2. Steel structures: AS 4100.
3. Cold-formed steel structures: AS/NZS 4600.

(5) Performance RequirementH1P1 is satisfied for structural steel sections if they are designed and constructed in accordance with one of the following:

1. Steel structures: AS 4100.
2. Cold-formed steel structures: AS/NZS 4600.
3. For structural stability, strength and deflection, and subject to (6), Part 6.3 of the ABCB Housing Provisions.
4. For corrosion protection, clause 6.3.9 of Part 6.3 of the ABCB Housing Provisions.

(6) For the purposes of (5)(c), Part 6.3 of the ABCB Housing Provisions may only be used where—

1. the building is located in an area with a wind class of not more than N3; and
2. the first dimension of steel sections is installed vertically; and
3. all loads are evenly distributed (unless otherwise noted or allowed for); and
4. the building is one for which Appendix A of AS 1170.4 contains no specific earthquake design requirements; and
5. the structural steel members are not subject to snow loads; and
6. the structural steel members are in buildings within geometric limits set out in clause 1.2 of AS 4055.

(7) The use of structural software is subject to the following:

1. 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.
2. Structural software referred to in (a) can only be used for buildings within the following geometric limits:
   1. The distance from ground level to the underside of eaves must not exceed 6 m.
   2. The distance from ground level to the highest point of the roof, neglecting chimneys, must not exceed 8.5 m.
   3. The building width including roofed verandahs, excluding eaves, must not exceed 16 m.
   4. The building length must not exceed five times the building width.
   5. The roof pitch must not exceed 35 degrees.
3. The requirements of (a) do not apply to design software for individual frame members such as electronic tables similar to those provided in—
   1. AS 1684; or
   2. NASH Standard – Residential and Low-Rise Steel Framing, Part 2.

(1) Diagrams depicting relevant roofing and supporting members and associated terminology used to describe them are set out in Figure H1D7a and Figure H1D7b.

(2) Performance RequirementH1P1 is satisfied for sheet roofing if it complies with one or a combination of the following:

1. Metal roofing:
   1. AS 1562.1; and
   2. 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.
2. Plastic sheet roofing: AS 1562.3.
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.

(3) Performance RequirementH1P1 is satisfied for roof cladding if it complies with one or a combination of the following:

1. Terracotta, fibre-cement and timber slates and shingles: AS 4597.
2. For roof tiles—
   1. AS 2050; or
   2. Part 7.3 of the ABCB Housing Provisions, provided—
      1. the building is located in an area with a wind class of not more than N3; and
      2. the roof tiles comply with AS 2049; and
      3. the roof has a pitch of not less than 15 degrees and not more than 35 degrees.

(4) Performance RequirementH1P1 is satisfied for timber and composite wall cladding if it is designed and constructed in accordance with—

1. for autoclaved aerated concrete wall cladding, AS 5146.1; or
2. for wall cladding, Part 7.5 of the ABCB Housing Provisions.

(5) Performance RequirementH1P1 is satisfied for a metal wall cladding if it is designed and constructed in accordance with AS 1562.1.

(1) Performance RequirementH1P1 is satisfied for glazing and windows if they are—

1. designed and constructed in accordance with AS 2047 for glazed assemblies in an external wall including—
   1. windows, other than those listed in (2); and
   2. sliding and swinging glazed doors with a frame, including French and bi-fold doors with a frame; and
   3. adjustable louvres; and
   4. window walls with one-piece framing; and
2. installed such that they comply with—
   1. AS 2047; and
   2. Part 8.2 of the ABCB Housing Provisions, provided that they are—
      1. in buildings that are within the geometric limits set out in clause 1.2 of AS 4055; and
      2. located in an area with a wind class of not more than N3.

(2) Performance RequirementH1P1 is satisfied for glazing in glazed assemblies if it—

1. complies with Part 8.3 of the ABCB Housing Provisions; or
2. is designed and constructed in accordance with AS 1288 for all glazed assemblies not covered by (1) and the following glazed assemblies:
   1. All glazed assemblies not in an external wall.
   2. Revolving doors.
   3. Fixed louvres.
   4. Skylights, roof lights and windows other than in the vertical plane.
   5. Sliding and swinging doors without a frame.
   6. Windows constructed on-site and architectural one-off windows, which are not design tested in accordance with AS 2047.
   7. Second-hand windows, re-used windows and recycled windows.
   8. Heritage windows.
   9. Glazing used in balustrades and overhead glazing.

(3) Performance RequirementH1P1(4) is satisfied for glazed assemblies at risk of human impact if they—

1. are designed, constructed and installed in accordance with—
   1. for glass, AS 1288; and
   2. for windows, AS 2047; or
2. comply with Part 8.4 of the ABCB Housing Provisions.

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.

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.

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—

1. the deck or balcony is not located in an alpine area; and
2. 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
3. the waling plate does not support—
   1. more than one floor; or
   2. loadbearing or non-loadbearing walls; or
   3. roof loads; and
4. the deck or balcony does not cantilever off the external wall; and
5. the total imposed load on the deck or balcony does not exceed 2 kPa; and
6. 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
7. steel framing constructed in accordance with H1D6(3); and
8. timber framing is constructed in accordance with H1D6(4); and
9. the external wall supporting the deck or balcony is constructed of—
   1. 190 mm thick fully core-filled concrete masonry, reinforced with vertical N12 bars at not more than 600 mm centres; or
   2. steel framing complying with H1D6(3); or
   3. timber framing complying with H1D6(4); and
10. 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
11. the waling plate is fixed to the external wall in accordance with clause 12.3.2 of the ABCB Housing Provisions and attached by—
    1. 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
    2. removing parts of the wall cladding so that the waling plate is directly fixed to the external wall, with—
       1. the junction of the waling plate and the external wall flashed in accordance with clause 12.3.3 of the ABCB Housing Provisions; and
       2. the cladding restored to its original strength by installing blocking supports as necessary on completion of installation; and
12. the deck or balcony is braced to prevent lateral movement in accordance with clause 12.3.4 of the ABCB Housing Provisions.

Performance RequirementH1P1 is satisfied for piled footings if they are designed and installed in accordance with AS 2159.