17 Dec 2019

Masterspec has almost completed its review of the latest updates to six Acceptable Solutions and Verification Methods. The majority of updates to Masterspec sections we expect to be completed by the 1st February release. But for those of you working in the office over Christmas or on long term projects, we thought it might help if we give you few big-picture pointers on issues that you should be aware may affect you.

On 28 November 2019, the transition period started for updates for these Acceptable Solutions and Verification Methods. They will become compulsory on a complex range of different dates (see critical updates below), so from those particular dates, if any previous versions of AS's or VM's are to be used they will be considered an alternative solution.

Summary of critical updates
The following is a brief review of key updates with a few additional comments from Masterspec:

B1 Structure: B1/AS1 (Amendment 18)

Good Ground
The Definition of Good Ground has been modified with the list of ground types that are not considered Good Ground being amended. Ground prone to liquefaction and lateral spread has had the limitation of only in "the Canterbury Earthquake Region" deleted, so it will eventually apply to the whole country.

MBIE has decided that, in order to enable Local Authorities to map such ground, this requirement won't become mandatory until 29 November 2021. Which means the old definition of Good Ground can be used until then.

Expansive Soil

The expansive soil requirements from NZBC SH/AS1 have been translated into NZBC B1/AS1 with an addition of a new section 3.2 Slab-on-ground in Expansive Soils. This section, in effect, adds new clauses to NZS 3604 and provides guidelines on; what is expansive soil, building parameters on expansive soils and slab modifications for expansive soils.

We believe this requirement will become mandatory from 31 March 2020. Also, SH/AS1 will then be revoked (removed) from the Building Code documents.

B1 Structure: B1/AS1, B1/AS3, B1/VM1 (Amendment 18)

Minor changes

These amendments consist mainly of Standards updates, these include:

  • AS/NZS 1163: 2016 Cold-formed structural steel hollow sections, Amendment 1 added, only minor correction.
  • AS/NZS 4600: 2005 Cold-formed steel structures, Amendment 1 added, involve quite a few minor corrections, including equations and figures.
  • AS/NZS 2566.1: 1998 Buried Flexible pipelines - Structural Design, Amendment 1 added.
  • AS/NZS 2566.2: 2002 Buried Flexible pipelines - Installation, Amendment 1, 2 & 3 added. These are mostly minor amendments except for the addition of more pipe material variants and the new material Polypropylene (PP). 
    Note, these added amendments do not now align with those in NZBC E1/AS1 or NZBC G13/AS2 (also these Standards are not cited at all in any of the NZBC G12/AS's)
  • AS 1397: 2011 Steel sheet and strip – Hot-dipped zinc-coated or aluminium/zinc-coated, has been updated from the 2001 version.

We believe these requirements will become mandatory 31 March 2020.

B2 Durability: B2/AS1 (Amendment 12)

Very minor correction
B2/AS1 clause 2.2.1 Schedule Maintenance, now references section 100 of the Building Act (was section 44).

Mandatory 31 March 2020.

E2 External Moisture: E2/AS4 (New AS)

E2/AS4 Light Steel Framing Weathertight Solutions for Buildings up to 3 Storeys or of 10m. A new short Acceptable Solution with a long name. The AS helps extend the compliance pathway for light steel framed buildings using the National Association of Steel Framed Housing (NASH) new document Building Envelope Solutions 2019. In June 2019 the Building Code Updates added the NASH documents to NZBC B1/AS1 for structure, now this new E2/AS4 adds them to weathertight solutions.

Requirements will become mandatory 28 February 2020.

H1 Energy Efficiency: H1/AS1 (Amendment 4)

Energy Efficiency Large Buildings - Lighting

What on the surface appears to be a minor amendment to H/AS1, turns out to be quite a significant change. In the updated H1/AS1, NZS 4243.2: 2007 Energy Efficiency Large Buildings - Lighting, has had Amendment 1 of the Standard cited. Amendment 1 changes the Standard quite dramatically by deleting all the existing methods of working out lighting efficiency and adding back only one new method. This new method is the Power Density Limits Method (PDLM). H1/AS1 clause 6.1.1 has been updated to reference the new section 3.3 (only) in the updated Standard, which of course now only uses PDLM.
Note, if using H1/VM1 clause 1.3.1 and modelling to NZS 4243.1 section 4.4, there is a "comment 1" that says you don't have to comply with NZS 4243.2 section 3.3.

Requirements will become mandatory 31 March 2020.