Plumbing modifications

If a plumber considers that the plumbing work they intend to carry out will not comply with the deemed to satisfy requirements of the plumbing regulations, they can apply to the VBA for a modification of the regulations. This will allow the relevant regulations to be modified (not apply) to the specific plumbing work being carried out. The plumbing regulations include Plumbing Regulations 2018 (the Regulations), the Plumbing Code of Australia and the Australian technical standards.

The VBA has power under the Building Act 1993 to make a declaration modifying the application of the plumbing regulations to specified plumbing work (which is the subject of the modification application).

The declaration will usually include specific conditions that must be met to ensure the plumbing work is still safe and meets the performance criteria.

Modification application process

Modification applications may be made by a registered or licensed plumber, the property owner or occupier, a plumbing inspector, the Secretary of a government department and public authorities.

The applicant should apply and have the modification approved by the VBA before the work commences.

To apply for a modification, you must complete and submit:

  1. the Plumbing modification application form (PDF, 213.83 KB) and return it with any relevant supporting documentation to the VBA.
  2. the Plumbing modification payment authorisation form (PDF, 169.62 KB). The fee is listed on the form.

You can submit your application by:

  • Email:
  • Fax: +61 3 9618 9062
  • In person: Victorian Building Authority, 733 Bourke Street, Docklands 3008
  • By mail: Victorian Building Authority, PO Box 536, Melbourne 3001

Note: For modifications to the Gas Installation Code you should contact Energy Safe Victoria.

What happens after you apply

We will assess the modification application, and then either approve or reject the application. If the application is approved, we will mail the approval to you. If the application is declined, we will contact you to discuss the application and/or to obtain further information.

The approval process may take up to 10 working days from receipt of application. If we request any further information, allow 10 working days from when we receive this information.

If your work is selected for an audit

If your plumbing work had a modification approved and it is selected for audit, you should advise the VBA Booking Officer of the modification when you book the audit. You will need to take a copy of the plumbing modification approval letter to the audit. You should also include modification declaration details on your compliance certificate for the plumbing work.

Modifications for laying of drains under a building

You may no longer need to apply for a modification if you are laying a sanitary drain under a building where the drain will service another building.

The Plumbing Regulations 2018 changed the requirements for the laying of a sanitary drain under a building in Victoria. The Regulations specify that work on a below-ground sanitary drain must comply with Clause 3.2 of AS/NZS 3500.2. However, you can get an exemption from Clause 3.2 if certain conditions are met.

You can find more information in our fact sheet Regulatory requirements for the laying of sanitary drains under buildings (PDF, 839.12 KB).

For more information

Refer to the Building Act 1993:

  • Section 221ZZO – Modification of plumbing regulations
  • Section 221ZZP – Matters Authority must consider before making a modification declaration
  • Section 221ZZQ – Procedure applying to hearings under this Part