Pipe suitability for hot and cold water services

Interpretation

Water supply pipes and fittings manufactured in accordance with standards cited in Acceptable Solution G12/AS1, or those specified in a CodeMark certificate, are deemed to comply with the Building Code, when correctly installed.

This means that water supply pipes and fittings that must be accepted by a building consent authority as complying with the Building Code are those that:

• comply with Acceptable Solution G12/AS1, Section 2.0 Materials
• hold current CodeMark product certificates.

Pipes and fittings not covered by the paragraph above may be considered by a building consent authority as an alternative solution. This guidance outlines factors for consideration when assessing if alternative pipes and fittings will comply with the Building Code.

Product certificates

CodeMark

All pipework systems with a current CodeMark product certificate must be accepted by building consent authorities as meeting the requirements of the Building Code. The certificate must be current, and the product must be used in accordance with the details noted on the certificate.

Search the CodeMark product certificate register.   

WaterMark

Products for use in water supply systems that have been certified and marked in accordance with the requirements of the Australian WaterMark Certification Scheme and listed on the WaterMark Product Database may be deemed to meet the requirements of the Building Code for their intended purpose.

Search the WaterMark schedule of products - watermark.abcb.gov.au 

AS/NZS 3500 Water services

Verification Method G12/VM1 previously referenced earlier editions of joint Australian/New Zealand Standards AS/NZS 3500.1 Plumbing and drainage – Water services and AS/NZS 3500.4 Plumbing and drainage - Heated water services. As part of the Building Code updates published in November 2023, these standards are now cited in Acceptable Solution G12/AS3. G12/AS3 requires the materials and products used with these design and installation standards to comply with Acceptable Solution G12/AS1 Section 2.0 Materials.

Earlier editions of the AS/NZS 3500 plumbing and drainage standards normatively cited specific product standards for acceptable pipes and fittings. These specific product standard conformance requirements were removed in the 2021 edition of these standards to avoid inconsistencies with the Australian WaterMark product certification scheme. New products and materials appendices were added to these standards to aid in determining if plumbing products and materials are fit for purpose.

Evaluating alternative materials for hot and cold water

Pipes and fittings that are not manufactured in accordance with standards cited in Acceptable Solution G12/AS1 may be considered by a building consent authority as an alternative solution. 

The guidance provided below includes factors for consideration when assessing if alternative pipes and fittings will comply with the Building Code. Information on some of the items below may be able to be obtained from the manufacturer or supplier of the product or material. Factors to consider include:

• the type of usage likely to occur
• the nature and temperature of the water to be conveyed and the risk of corrosion, degradation and leaching
• the nature of the environment, the ground and the possibility of chemical attack therefrom
• the physical and chemical characteristics of the materials and products
• compatibility of materials and products
• the pressure rating of pipes and fittings and
• accessibility for inspection and maintenance.

Additional factors to consider when evaluating alternative products and materials as being suitable for use with hot and cold potable water services:

1. Overseas approvals

Many products that are manufactured overseas have approvals that specifically include use with potable water. For example, the British Board of Agrément (BBA), Deutscher Verein des Gas- und Wasserfaches (DVGW), National Sanitation Foundation (NSF) and American National Standards Institute (ANSI) certified products and materials.

2. Manufacturing and installation Standard(s), including durability tests:

• Identify the Standard(s) the pipe and fittings are manufactured and installed to.
• Determine if these contain tests to establish the durability of the pipe and fittings for New Zealand conditions.
• For plastic heated water pipes, confirm the stress regression curve for the plastic material demonstrates the required level of durability to meet Building Code clause B2 Durability at the intended operating temperature.

3. Statements/tests for not contaminating the water:

• Identify how the manufacturer/supplier shows that the pipe and fittings will not contaminate the potable water supply. For example, test certificates verifying compliance with AS/NZS 4020 or BS 6920.
• Identify how the manufacturer/supplier demonstrates the product is lead free.

4. Resistance to light transmission through the pipe wall:

• Determine how the manufacturer/supplier shows the pipe will not transmit light to prevent algae growing in the pipe.

5. Resistance to ultraviolet light - for external installation:

• Determine how the manufacturer/supplier shows the pipe is resistant to ultraviolet light when installed in locations exposed to sunlight.

6. Clear identification to avoid confusion with similar products:

• Confirm the product is clearly identified with visible external marking complying with the manufacturing Standard, particularly when compared with similar-looking products intended for a different use.

7. Manufacturer's data relating to intended use:

• Check the manufacturer's information demonstrates how the product contributes to compliance with the Building Code, including clauses G12 Water supplies and B2 Durability, and explains how the product should be used and installed.

8. Appraisal results and accreditation:

• Review any independent supporting documentation showing compliance with the Building Code.

If you want to substitute a pipework system originally specified in your building consent application, you need to show the council how it meets the Building Code requirements.

Read about product substitution and variations.

Summary of pipes and fittings materials and standards

Materials for hot and cold water that must be accepted by building consent authorities are as follows:

• Copper pipes - NZS 3501 or AS 1432 (Type A, B, C)* 
• Copper alloy fittings - AS 3688
• Polybutylene (PB) pipes and fittings - AS/NZS 2642 Parts 1, 2 and 3
• Cross-linked polyethylene pipes - AS/NZS 2492**
• Cross-linked polyethylene pipe fittings - AS/NZS 2537: Parts 1, 2, 3 and 4
• Stainless steel pipes - AS 5200: Part 053 

Materials for cold water only that must be accepted by building consent authorities are as follows:

• PVC-U pipes and fittings - AS/NZS 1477
• Polyethylene (PE) pipes - AS/NZS 4130 
• Polyethylene (PE) pipe fittings - AS/NZS 4129

*Copper pipe and associated fittings are not dimensionally compatible with copper pipe made to NZS 3501.

**Cross-linked polyethylene pipes used for hot water shall have a nominal pressure rating of PN16 or PN20.

All guidance related to G12 Water supplies