Renovating or refurbishing wet areas in your home

This page has information on the approvals you need to renovate wet areas of a house, shed or garage in the Northern Territory.

Wet areas are rooms such as a bathroom, toilet, ensuite, powder room or laundry.

Your building project will fit in one of the following approval groups: 

  • work that needs a plumbing certificate
  • work that needs a plumbing certificate and a building permit
  • work that does not need approvals.

If your renovation is for an apartment or townhouse, you may need different approvals. For more information, talk to a building certifier. Read about engaging a registered building certifier.

Always use a licensed and registered plumber

You should always use a licensed plumber for plumbing work, including work to fixtures and fittings, whether or not you need a plumbing certificate.

A licensed plumber checks plumbing work and installations against current plumbing codes and standards.

Go to the Plumbers and Drainers Licensing Board website to find a licensed plumber.

Getting plumbing certification

A certifying plumber and drainer is a licensed plumber who is also registered with the Building Practitioners Board.

A certifying plumber and drainer can issue your plumbing and drainage work a certificate of compliance when it is done. 

If your project involved any drainage works, the certifying plumber and drainer will also lodge a copy of the plumbing certification documents with the Director of Building Control to be included on the building file for the property. 

Read about access to building files.

Go to the Building Practitioners Board website to find a certifying plumber.

Keep building work documents safe

Keep all your building work documents, such as plumbing certificates and inspection reports. You may need these to support the value of your property if you decide to sell it. 

Work that needs a building permit and plumbing certification

The table below lists wet area building work that requires a building permit before you start work and certification at the completion of work.

Before starting work you must engage a registered building certifier. 

You will also need to engage a certifying plumber and drainer.

Read about engaging a registered building certifier and getting a building permit.

Type of work


Putting in or taking out partitions or walls

  • dividing a room to create a separate area
  • removing a partition to incorporate a toilet in a bathroom
  • enclosing an outside laundry

Breaking into or altering the walls or floors

  • putting new plumbing through or into the wall or floor
  • installing or increasing the size of a window or door
  • adding or removing a wall

Installing new fixtures or fittings where they do not already exist

  • putting in a new bath
  • putting in a shower where there used to be a bath

Work that needs plumbing certification only

The table below lists wet area building work that requires only certification by a certifying plumber and drainer at the completion of work.

Type of work


Replacing any external sanitary drainage or installing a new water supply

  • digging up pipes and putting in new ones

Replacing any plumbing fixture or fitting with a different component, providing there is no alteration to existing services

  • changing a bath to a spa (if wall or floor penetration is not required)
  • removal and capping of fixtures such as a shower, bath, toilet and hand basin.

Work that does not need approvals

The table below lists wet area building work that does not need building approval or plumbing certification.

Type of work


Maintenance or repair of fittings, fixtures and floor and wall tiling

  • replacing damaged tiles
  • changing a tap or fitting
  • repairing or changing a hand basin or toilet cistern.

New joinery work

New cabinets and benchtops provided there is no extension or inclusion of new plumbing work.

Replacing existing plumbing fixtures or fittings with similar

  • a new bath to replace an old bath
  • a basin to replace a basin
  • replacement of taps, faucets and the like.

Shower screen

Installing a new or replacing an existing shower screen.

Retiling an existing wet area

  • replacing small areas of damaged tiles
  • overall retiling of a wet area.

If your work involves removing and replacing tiles, it may damage the waterproof membrane that protects the floor and walls. You can protect the membrane in these areas by reinstalling waterproofing and checking it is done in accordance with Australian Standard AS3740 (Water Proofing of Wet Areas).

Last updated: 31 March 2016

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