In Western Australia, the design, construction and installation of private swimming and spa pools and their safety barriers is subject to strict building requirements.

The Building Regulations 2012 (the Regulations) requires all private swimming and spa pools that contain water that is more than 300 mm deep to have a compliant safety barrier installed that restricts access by young children to the pool and its immediate surrounds,

In Western Australia, there are two sets of safety barrier requirements depending on when the private swimming pool was installed or when plans for the installation of the pool were submitted to the permit authority for approval.

Generally:

Post 1 May 2016 private swimming pools are required to have safety barriers that comply with the edition of the Building Code of Australia (BCA) currently in effect. The BCA references AS 1926.1:2012 (Safety barriers for swimming pools) and AS 1926.2:2007 (Location of safety barriers for swimming pools) incorporating amendments 1 and 2;
Pre 1 May 2016 private swimming pools can continue to comply with their existing requirements under the Regulations or alternatively comply with the new requirements (that is the BCA).

Security Doors Around Private Swimming and Spa Pools

Doors that form part of the pool barrier must have the following characteristics:

be fitted with a self-closing device that will automatically return the door to the closed position. It must allow the self-latching device to operate without the application of manual force from any position that the door is capable of opening, including when resting on the latch;
be fitted with a self-latching device that will prevent the door from being re-opened without the application of manual force on the latch release mechanism;
the operating part of the latch release mechanism must not be less than 1500 mm above the floor;

You can get more detailed information from the Government of Western Australia, Department of Commerce, Building Commission.