This is a subject that has created a huge amount of governmental paperwork and regulations. The rules were upgraded in November 2001.
Your friends with pools built prior to November 2001 have a different set of rules to you.
The current rules and gates must comply with AS1926.1.
I thought about presenting the rules for you in detail however the Western Australian Building Regulations web site has 22 pages with diagrams to explain the requirements.
My summary is:
All private swimming pools or ponds that are in excess of 300 mm deep must have a compliant barrier that restricts access by young children to the pool and its immediate surrounds.
The non-scalable barrier or fence must be 1200 mm or higher with a gate that opens outwards from the pool area.
Doors and windows from the house must not allow direct access to the pool area.
Types of fences
Fences can be made of many materials however most are metal, timber, brick or glass.
Panels are available in pre made sections and can be installed by contractors or the talented owner. There are several styles and range from $200/ metre upwards.
Glass panels are supported by metal posts. This is the lowest priced glass fencing and prices are around $500/metre to supply and install.
Fully frameless glass
This is the top of the range in swimming pool fencing.
Heavy duty panels of safety glass are supported by stainless steel stirrups that are supported in a concrete foundation.
An estimate to supply and install standard panels is $800/ metre.
Special sized panels can be supplied at extra cost to secure fencing over steps, retaining walls and garden beds.