Auckland mayoral candidate Vic Crone has come up with a novel way of cracking down on land-banking developers.
She wants to use water meters to find empty houses. Homes or properties where no water is being used would be slapped with hefty rates bills.
The council says land-bankers are sabotaging attempts to speed up the construction of new homes.
"I'm proposing to bring a targeted rate, working with Watercare to monitor which homes are available and which homes are unoccupied," she says. "We need to get as many homes as possible available for people to live in in Auckland."
Empty homes are just part of the picture. Empty sections contribute to the shortage as well.
Ms Crone says developers land-banking instead of building would pay higher rates for failing to act.
"And if they don't respond to that, they're going to leave the council with no choice but to rezone that land and collapse the value of it."
Progress is especially slow in the zones set aside for fast-tracked construction -- the so-called "special housing areas" where developers get quicker resource consents.
Around 56,000 new sections have been created, but only 1000 homes have been built.
Deputy Mayor Penny Hulse blames land-bankers and says only a law change could force developers to act.
"What we also need is an imperative to stop the people making money out of land-banking," says Ms Hulse.
Housing Minister Nick Smith couldn't be reached today, but last month he told Newshub land-banking is not a problem.
That puts him at odds with both the current council and the woman who is looking to take over as mayor.