Plumbing and drainage work and building consents

Last updated: 4 October 2018

If you are undertaking plumbing and drainage work, you may not need a building consent if an authorised person completes the work.

You must employ an authorised person to carry out building work listed in Part 2 of the Building Act's Schedule 1 in order for it to be exempt from needing a building consent. If an authorised person does not complete the work, then it is not exempt.

Work in Part 2 relates to sanitary plumbing and drainlaying.

The term ‘authorised person’ is defined by the Building Act. For building work in Part 2, it covers:

  • registered certifying plumbers and drainlayers
  • registered plumbers and drainlayers working under supervision
  • plumbers and drainlayers with a provisional licence working under supervision
  • trainee plumbers and drainlayers working under supervision. must make sure the plumber or drainlayer you are using for your building work has current authorisation from the Plumbers, Gasfitters, and Drainlayers Board.

You must make sure the plumber or drainlayer you are using for your building work has current authorisation.

Check the online register of the Plumbers, Gasfitters and Drainlayers Board to make sure.

Part 1 and Part 3 of Schedule 1 also list work that can be done without a building consent.

Building consent exemptions includes building work listed in Part 1 that doesn’t need a building consent and can be done by anyone.

Engineer-designed exempt work includes information about work listed under Part 3 that doesn’t need a building consent if designed or supervised by a Chartered Professional Engineer.

What the exempt work includes

The following guidance includes plumbing, drainage and water heaters, and is from Part 2 of our guide to Building work that does not require a building consent.

Plumbing and drainage
32. Repair, maintenance, and replacement of sanitary plumbing and drainage
33. Drainage access points 
34. Minor alteration to drains 
35. Alteration to existing sanitary plumbing (excluding water heaters) 
Water heaters
36. Repair and maintenance of existing water heater 
37. Replacement of open-vented water storage heater connected to supplementary heat exchanger
38. Replacement or repositioning of water heater that is connected to, or incorporates, controlled heat source

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: