Response to Question
Plumbing and Drainage Act 2018 (PDA);
Section 64; Complying with code requirements for plumbing and drainage work
(1) A person who carries out plumbing or drainage work must ensure the work complies with the code requirements for the work.
Maximum penalty—100 penalty units. Penalty Infringement Notice $1334.00
Plumbing Code of Australia (PCA);
BS5.1.3 Protection types and Hazard Ratings
Cross-connection hazards within the site must be rated in accordance with—
The following are High Hazard for the purpose of individual protection:
(ii)Bidets and douche hoses.
AS/NZS3500.1:2018
Section 12 INSTALLATION OF WATER SUPPLY TO SPECIFIED FIXTURES.
12.2.1 Bidet
A bidet SHALL be installed with a registered break tank or a testable device conforming to AS/NZS 2845.1 or AS 2845.2.
12.2.2 Bidette
A bidette SHALL be installed with a non-testable device of 25mm air gap.
12.2.3 Toilet seat douches
Where the douche outlet, in all positions, is at least 25mm above the overflow level of the pan, backflow prevention is not required.
Where the douche outlet, in any position, is less that 25mm above the overflow of the pan, a high-hazard backflow prevention device, conforming to AS/NZS 2845.1 or AS 2845.2 shall be installed.
WMTS-051:2016
Section 8.3 Backflow prevention
The douche seat shall be supplied with a low hazard mechanical backflow prevention device complying with AS/NZS2854.1
Therefore; when installing a bidet or bidet seat the plumber MUST ensure he or she complies with the section 64 of the PDA, section BS5.1.3 of the PCA and the deemed to satisfy provisions of section 12 of the AS/NZS35001.2018.