The report, released tonight, recommends scrapping rules that force developers to include a minimum number of car park spaces when building housing.
The "Wasted Space" report found that upwards of 40 per cent of car parks were left empty each night in apartments in Sydney, Melbourne, and Brisbane.
"State and local governments typically require new housing to include off-street parking — often much more than residents want, needlessly driving up the price of housing," the report said.
The report found these parking minimums increased construction costs by $70,000 for a two-bedroom Sydney apartment.