The rules for these contributions are set out in policy C599 - Community Amenity Contributions in Direct Control Provisions, which was approved by City Council on Tuesday July 10, 2018, and updated on December 7, 2020. This policy establishes how much must be contributed, the types of development that must have contributions, and what is considered an amenity.
The Guidebook for Community Amenity Contributions explains how the policy works in plain language.