Central and local government are developing a comprehensive plan to deal with the leaky homes crisis.
The plan follows indications that the cost of fixing home owners' rotting houses is three times greater than earlier thought.
The mayors of six metropolitan areas were summoned to Parliament on Monday for talks with Building and Construction Minister Maurice Williamson.
The meeting was called after Mr Williamson received a report on leaky homes from accountancy firm PricewaterhouseCoopers.
The report is reported to put the cost of fixing rotting homes at $11.5 billion, much higher than the $3.6 billion mentioned by Mr Williamson at a select committee six weeks ago.
The plan under formulation is understood to involve central and local government, builders, developers and owners themselves in the process of repairing homes.
Where public money is used, people would be asked to sign a waiver, guaranteeing the money would be repaid from their estate when they die.