31 Jan 2019

In BC Update 243 MBIE announced that from the 30 November 2018 the transition period started for amendments to seven Acceptable Solutions and four Verification Methods. During the transition you can use either the old version or the new amended version. On the 31st March 2019 the amendments will become compulsory and the new amended versions must be used. However, after March if any previous versions were to be used, they must be considered an alternative solution proposal.

Summary of changes

The following is a brief description by MBIE of the changes to each amended Acceptable Solution or Verification Method, with a few additional comments from Masterspec.

B1 Structure: B1/VM1 (Amendment 17)

  • Paragraph 2.1: Added a reference to Amendments 4 and 5 of AS/NZS 1170.2:2011, Structural Design Actions - Wind Actions.

    Amendment 4 deals with debris loadings and internal pressures, Amendment 5 covers some table amendments. They do not affect Masterspec sections.

  • Paragraph 5.1.4A: Section 13 of NZS 3404.1:1997, Steel structures standard, which covers the design of component members and structures, has been replaced by AS/NZS 2327:2017, Composite Structures - Composite steel-concrete construction in buildings.

    This addition allows a wider range of composite structures to be designed under the NZBC.  Guidance notes on AS/NZS 2327 added to some Masterspec sections.

  • Paragraph 5.1.9A: B1/VM1, Appendix C: Corrosion Protection has been replaced with the new technical specification SNZ TS 3404:2018, Durability requirements for steel structures and components.

    Reference is given in B1/VM1 but is handled under B2/AS1 (see B2 notes below). This addition allows more designers to specify corrosion protection systems, refer to B2 comments.

  • Paragraph 12.1: Added a reference to Amendment 1 of NZS 4211:2008, Specification for performance of windows. 

    Amendment 1 adds Extra High wind zone, refer to E2 comments

Note; NZS 3404.1;2009 version has been withdrawn by Standards, which means NZS 3404.1;1997 version is the current version and is also cited by NZBC.


B2 Durability: B2/AS1 (Amendment 10)

  • Paragraph 3.6.1: The new technical specification SNZ TS 3404:2018, Durability requirements for steel structures and components has been added as an Acceptable Solution for structural steel building elements.

    This amendment provides clarity on acceptable methods of steel protection and avoids the need to justify alternative solution proposals. SNZ TS 3404 references and is based on the much more extensive AS/NZS 2312 set of Standards.

    Masterspec has added SNZ TS 3404 as a reference along with the existing references to the various parts of AS/NZS 2312. The AS/NZS 2312 set (referenced by SNZ TS 3404, but is not cited by NZBC.) has also been retained to keep a wider range of options, including proprietary ones, available for steel protection. Masterspec corrosive zone tables have been amended to include reference to SNZ TS 3404.


E2 External Moisture: E2/VM1, E2/AS1 (Amendment 8)

  • Paragraph 1.2: Added a reference to Amendment 1 of NZS 4211:2008, Specification for performance of windows.

    Amendment 1 adds Extra High wind zone category which brings it in line with NZS 3604. This new wind zone will require either Class 1 or Class 2 testing on new cladding systems for E2/VM1 compliance. The new testing requirements are for ensuring adequate weathertightness performance of claddings in Extra High wind zones.

    A rigid underlay is required in this situation, but is not part of the VM test of the cladding system. Note that the revised testing requirements will apply to all new testing, however current test certificates will remain valid. Masterspec sections were already using the Extra High wind zone, so they remain the same.

    Note; NZS 4211 has the same wind zones as NZS 3604 but uses different pressures for test purposes.


G12 Water Supplies: G12/VM1, G12/AS1, G12/AS2  (Amendment 11)

  • Cited Standards AS/NZS 3500.1:2015, Plumbing and drainage - Water services and AS/NZS 3500.4:2015, Plumbing and drainage - Heated water services, have both had an Amendment 1 added.

    Both of these Amendment 1's have added common Stainless Steel piping and jointing methods to the Standard, this effectively makes Stainless Steel piping an Acceptable Solution.

    Note; although this has not affected any of the Masterspec sections, while checking them we did take the opportunity to update and clarify, in the same sections, G12/AS1 requirements for overflow trays for storage HWCs.

G13 Foul Water: G13/AS1, G13/AS2, G13/AS3  (Amendment 7)

  • G13 cited Standard AS/NZS 3500.2:2015, Plumbing and drainage - Sanitary plumbing and drainage

    Has had Amendment 2 of the Standard added.

  • G13/AS1 Sanitary Plumbing, Paragraph 7.1.3 and G13/AS2 Drainage, Paragraph 6.1.3

    Have had a references added allowing air testing of pipework for water tightness to AS/NZS 3500.2, 15.3.

    This amendment provides another acceptable method of testing sanitary and drainage pipe work. Masterspec sections now include this option.

  • G13/AS3 Plumbing and Drainage, Paragraph 2.0.1:

    References added for Sections 15 (Testing) and 16 (Vacuum Systems) of AS/NZS 3500.2.

    As above, Section 15 amendment provides another acceptable method of testing drainage and this has been included in the Masterspec sections. Section 16 includes an acceptable solution for vacuum drainage installations. Vaccum drainage systems are very complex, the Masterspec sections do not cover such systems. However we have added a reminder guidance note recommending expert design advice if you need a vacuum drainage system.


Simple House: SH/AS1

  • MBIE had proposed to revoke SH/AS1 as part of the November 2018 Update.

    However they found that the ‘Slab-on-ground in expansive soils’ information for foundation design within SH/AS1 is not contained in any other Acceptable Solution. MBIE proposed to transfer this information to B1/AS1 in a future amendment. Once transferred, SH/AS1 will be revoked.