Height restrictions. Maximum floor-space ratios. Parking space mandates. Broad heritage protections. Minimum lot sizes. Setback requirements.
These are just some of the self-imposed barriers prolonging Australia's housing crisis, according to the federal government's independent think tank.
Layers of well-meaning controls imposed by governments over time were blocking or limiting the size of new developments, the Productivity Commission said in an interim report of an inquiry into the impact of regulation on Australia's housing shortage, released on Tuesday.
A lack of homes where people want to live has caused housing unaffordability to increase dramatically in recent years.
The amount of time it takes an average household to save up a 20 per cent deposit on a typical home had blown out to 11 years from eight years in 2005, said Productivity Commission chair Danielle Wood.
"We cannot solve our housing affordability problem unless we build more homes where people want to live," she said.
One of the key levers governments can pull to boost housing supply is to reduce regulations that determine where homes can be built and what form they can take.
"Regulation is important, but too much or poorly designed regulation can stop new homes being built, make projects slower and more expensive, and reduce the types of housing available to us," Ms Wood said.
"The rules should allow us to build enough housing in the right places, while still protecting the things Australians value."
The report found that easing zoning laws to allow up to three-storey developments across most residential land, similar to successful reforms in New Zealand, would help shift the dial.
It also recommended enabling mid- or high-rise apartments near existing public transport, reducing minimum lot size requirements and allowing homes to be built in commercial zones.
Controls that limit the range of dwelling types that can be built - such as maximum floor-space ratios, minimum dwelling sizes, storage requirements for apartments, setback requirements and height restrictions - should also be removed or reduced.
Most of these levers are at the hands of state, territory or local governments.
Some have already been pulled.
NSW's low- and mid-rise housing policy encouraging denser residential development within walking distance of activity hubs will increase the potential capacity of new homes by 650,000, the report found.
But of these, only 240,000 will be commercially feasible.
It underscored the need for governments to remove design restrictions that make developments commercially unviable, the commission said.
Slow and complex approvals processes also delayed new housing and made some developments unviable, the report said.
Builders reported battling to navigate overlapping approvals and different levels of government, referral agencies and infrastructure providers, who often did not talk to each other.
"One developer told us that preparing reports and waiting for approvals had added more than three years to the timeline of a 1600-lot development in Melbourne’s growth corridor," Ms Wood said.
