Copper water pipe and fittings

Copper pipe

New Zealand has traditionally used copper pipe and fittings manufactured to NZS 3501. This Standard is cited in G12/AS1.

Guidance for plumbers, plumbing designers, plumbing distributors, building owners and building consent authorities about copper pipe and fittings manufacturing standards.

This information was confirmed as current in February 2016. It originally appeared in Codewords newsletters prior to January 2014.

  • Published on 1 May 2011
  • Of interest to Building consent authorities, Designers, Plumbers,
  • 1st edition

Only New Zealand and Ireland use copper pipe manufactured to the dimensions in this standard, and Ireland is phasing out this size of copper pipe.

The dimensions in NZS 3501 are based in internal bore sizes and the recognised standards in other parts of the world, including AS 1432 and AS 3688, are metric sizes based on outside diameter.

Copper water pipes


Copper pipe used in New Zealand and manufactured to NZS 3501, is made on indent order in special production runs by Australian copper pipe manufacturers. Australian copper manufactures export copper pipe to AS 1432 and copper fittings to AS 3688 to the Pacific and Asia. Copper pipe and fittings manufactured to these standards are cited in G12/VM1 because they are referenced from AS/NZS 3500.1:2003 Plumbing and Drainage - Water Services.

NZS 3501 copper complies with G12/AS1, and Australian copper pipe and fittings made to AS1432 and AS3668, comply with the Building Code by reference in AS/NZ 3500.1 cited in G12/VM1. It is then up to plumbing merchants, in conjunction with the plumbing industry, to decide which copper pipe and fittings will be stocked, sold and installed in New Zealand.

All guidance related to G12 Water supplies

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: