AS/NZS 3500.4 HEATED WATER SERVICES UPDATED
AS/NZS 3500.4:2003 Plumbing and Drainage - Heated Water Services, has been updated to a 2015 version. The purpose of the update seems to have been mostly for Australian purposes, however among other things, there has been some clarification of the requirements for the installation of solar hot water heaters.
However, AS/NZS 3500.4:2003, is cited and recognised by the NZBC, but AS/NZS 3500.4:2015 has not yet been cited. So at this point in time the 2003 version is the means of compliance with the NZBC, even though it is has been superseded by Standards NZ.
The main Acceptable Solution for this is NZBC G12/AS2 Solar Water Heaters, in particular section 5.0, where installation requirements must be to AS/NZS 3500.4:2003, part 4 Installation of Cold and Heated Water Piping and Controls, unless modified by the Acceptable Solution. This is slightly confusing as AS/NZS 3500.4:2003, Part 6 is Installation of Solar Water Heaters? The Standard is also cited for larger (200 to 450 litre) hot water storage tanks in roof spaces, NZBC G12/AS2, part 1.1.1.c.ii.
As a Verification Method for hot water services, AS/NZS 3500.4:2003 is the only method to satisfy NZBC G12/VM1.
Although not cited in NZBC G12/AS1, Masterspec mostly use AS/NZS 3500.4:2003 (and AS/NZS 3500.1:2003) as an option to NZBC G12/AS1 for pressure testing the water systems. The Standards have much more thorough and rigorous testing than the NZBC. The Standards, unlike NZBC, also take account of system fittings and fixtures that may not be suitable for the same full pressure test.
Until the NZBC cites the new 2015 version of these Standards, or MBIE issues a new directive, Masterspec will continue to use the compliant 2003 version. If you want to use the 2015 version consult with the BCA as to their requirements before changing the specification.
All related Masterspec work sections have been amended with "2003" being added to the Standards number. Remember if a Standard has no year stated it is automatically the latest version (refer 1233 REFERENCED DOCUMENTS, clause 1.1).
Masterspec will monitor the situation and keep you informed on developments.
NZBC G12 WATER SUPPLIES
NZS 3500.4 Plumbing and Drainage - Heated Water Services