AMENDMENTS TO NZBC B1 STRUCTURE AND NZBC B2 DURABILITY
Published 29 March 2017
The Amendment to NZBC B1 and NZBC B2 Verification Methods and Acceptable Solutions involves, substantially for B1 and wholly for B2, the update of NZS 4223.2 Glazing in Buildings - Insulating Glass Units from 1985 to 2016, and NZS 4223.3 Glazing in Buildings - Human Impact Safety Requirements to 2016 plus amendment 1.
NZBC B1 STRUCTURE (Amendment 15)
The previous Amendment 13 (June 2016) to NZBC B1/AS1 formalised the requirement for glass barriers to structurally comply with NZS 4223.3:2016 section 22. This new Amendment 15 still uses NZS 4223.3:2016 but modifies clause 22.4.3 of the Standard. This modification is similar to the Standard except for new testing and deflection requirements. So the basic design of a barrier will be as per the Standard but proof of compliance may be more onerous due to the modification. It is worth remembering that not all glass screens, fences or balustrades are barriers, as barriers are to prevent falls of 1000mm or more, however other parts of the Standard may apply.
The other major amendment to NZBC B1/AS1 involves modifications to the requirements for timber deck structures using NZS 3604, Figures 7.10(b) and 7.10(c) and deletes the related part clause 188.8.131.52(c). These modifications mostly affect bolting requirements.
NZBC B2 DURABILITY (Amendment 9)
NZBC B2/AS1 has a new section 3.5 Insulating Glass Units (referred to as IGU's and sometimes double glazing). This section cites NZS 4223.2 as an Acceptable Solution, but modifies clause 5.3 of the Standard, that is to do with Marking of IGU's. This modification defines what information should be marked and that the mark should be permanent (labels are no longer allowed). It also requires the marking to be visible after installation, which is a different approach.
As Masterspec already used the latest versions of the NZS 4223 set, changes to sections have been relatively minor and mostly related to the modification requirements. However a large number of sections have been affected particularly the glazing and window sections.
All affected sections have now been updated.