The Environmental Planning and Assessment Amendment (Development Contributions) Act 2005 provides for the use of planning agreements, which may be applied for affordable housing purposes.
Resources:
The Centre for Affordable Housing's National Leading Practice Guide and Toolkit contains more detailed information about voluntary negotiated agreements.
Planning NSW provides an overview, practice notes and a template planning agreement:
> Practice Notes and Template Planning Agreement
> Changes to the public notice requirements for planning agreements
Some examples of planning agreements policies:
> Canada Bay Planning Agreements Policy
> Randwick Council Planning Agreements Policy
> Burwood Planning Agreements (Planning Agreements Policy 2005)