The transition period for these changes were 12 months, ending on 1st November 2024 with the exception of lead in plumbing. This will have an extended transition date until 1 September 2025.

From the 2^nd November 2024, the most update to date versions of acceptable solutions and verification methods will need to be used.

A summary of the changes can be found below. Click here for the full details.

Plumbing and Drainage

Surface Water

E1/AS1 has some minor amendments including the standards referred to within Table 4 Acceptable Material Standards for Downpipes and Table 6 Acceptable Material Standards for Roof Gutters.  Table 4 also now includes polyethylene pipe.

There is only a minor amendment to E1/VM1 to figure 3 Pipe flow relationships for different combinations of internal diameter, velocity, and gradient.

Plumbing and drainage Standards

The adoption of the latest version of the AS/NZS 3500 plumbing and drainage standards is a key part of these amendments. MBIE participated in the development of these standards and the new versions include a number of New Zealand-specific requirements, making some of the previous New Zealand Building Code modifications to the standards no longer necessary. These standards are cited as compliance pathways in several Acceptable Solutions.

Lead in plumbing products

The amended Acceptable Solution G12/AS1 limits the maximum lead content in any product that contains copper alloys, intended for use in contact with potable water for human consumption. This includes products such as pipe fittings, valves, taps, mixers, water heaters, and water meters. This amendment also clarifies that copper alloy water supply system components complying with this Acceptable Solution must be dezincification resistant to comply with AS 2345.

Water temperatures

MBIE has amended Acceptable Solution G12/AS1 to lower the maximum hot water temperature delivered at the tap for most buildings from 55°C to 50°C. The amendments also include additional temperature control devices to give plumbers more ways to limit hot water temperatures. These changes do not apply to hot water used in kitchens or laundries, nor to the minimum temperature of hot water in a storage tank. The changes apply only to fixtures used for personal hygiene in new plumbing systems.

Protection of potable water

The amendment to Acceptable Solution G12/AS1 to improve the requirements to protect potable water from backflow contamination.

Water supply system components

MBIE has amended Acceptable Solution G12/AS1 to improve the requirements for plumbing components in water supply systems. G12/AS1 Table 1 Material for Hot and Cold Water, has been expanded to include cross-linked polyethylene and stainless steel whilst galvanised steel has been removed.  Also, the relevant standards referred to have been modified.

The inclusion of Expansion vessels as an option in lieu of expansion control valves in valve vented hot water storage systems, amending requirements for labelling of non-potable water pipework and removing reference to NZS 5807.2

G12/AS2 only includes a minor amendment in relation to allowable diameter of roof penetrations in profiled metal roofs using an EPDM boot.

MBIE has also amended Verification Method G12/VM1 to include a new design method to size water pipes. AS/NZS 3500.1 and .4 are now G12/AS3.

Foul Water

NZBC G13/AS1 Sanitary Plumbing, Table 1 Pipes, traps and fittings, has been expanded and now includes polypropylene pipes and stainless steel pipes and NZBC G13/AS2 Drainage, Table 1 Materials for drainage pipes, has been expanded to include stainless steel and vitrified clay.

Protection from Fire

The changes to Acceptable Solution C/AS1 require interconnected smoke alarms as the minimum fire safety system required in each household unit.

The amended Acceptable Solutions C/AS1 and C/AS2 now cite NZS 4514: 2021 for the installation of interconnected smoke alarms to improve the fire safety in new residential homes.

New versions of standards for sprinkler systems, fire alarm systems, interconnected smoke alarms, and smoke control systems have been cited in Acceptable Solutions C/AS1, C/AS2, F7/AS1 and Verification Method C/VM2.

Fire safety system standards

• NZS 4512:2021 Fire detection and alarm systems in buildings
• NZS 4514:2021 Interconnected smoke alarms for houses
• NZS 4541:2020 Automatic fire sprinkler systems

NZBC C/AS1 and NZBC C/VM1 have been split into two separate documents, with the layout of these documents modified

NZBC C/AS1 Appendix C Fire Safety Systems and Appendix D. Modifications to standards have been added and within NZBC C/AS2 Appendix A Fire Safety Systems and Appendix B Modification to Standards, have been overhauled.  These appendices include information previously included within F7/AS1 and now cite NZS 4514:2021 for the installation of interconnected smoke alarms to provide the fire safety in residential homes

Within NZBC C/AS1, clause 5.3 External Cladding Systems has been amended and Appendix E Fire Test Methods, has been added.  The requirements and classification of non-combustible and limited combustible materials now align with NZBC C/AS2.

Within NZBC C/AS1, Part 3 Means of Escape, has been substantially expanded.  This now includes requirements for the height and width of escape routes, maximum travel distances and external safe path protection.

There are numerous other minor changes within C/AS1, C/AS2, C/VM1 and C/VM2, including updating standard references to the latest version such as AS/NZS 3000:2018 and AS 1668.1:2015, and NZBC C/AS1 refers to G9 in relation to electrical fire safety, this now aligns with NZBC C/AS2.