The current lead-time for bringing new greenfield land onto the housing market typically takes around five years but can take as long as ten years.
The GAA's reforms will cut out duplication in planning to make sure the housing production pipeline flows as quickly as it can.
An increase in the supply of developable land will create downward pressure on housing prices.
The GAA is advising the Planning Minister on development trends and monitoring land supply across the growth areas, to keep demand pressures in check.
The GAA is also undertaking, with the Urban Development Program, a detailed analysis of land availability in the growth areas to give a more complete picture of timing, availability and competition for land supply.
The GAA is also supporting councils across the growth areas to prepare 37 Precinct Structure Plans - the masterplan of new communities.
In Hume, the GAA is working with Hume City Council to increase the supply of zoned land in Craigieburn and Greenvale, allowing more developers to enter the market.
Casey-Cardinia is a priority area. Five Precinct Structure Plans (PSPs) will be completed by 2008, putting 28,500 new lots on the market, or about eight years supply.