Auckland Council's top building official says wide-scale demolition of rotting townhouse units might be the best solution - but many properties can be fixed.
Building policy manager Bob DeLeur said the wrecking ball was needed sometimes, but was not always the answer.
"Many [properties] are being remediated at substantially less cost than it would cost to demolish and rebuild these complexes," he said.
"In some instances, demolition may be the best option but property owners should seek good advice before deciding on that route."
The building industry had changed substantially since the rotting homes problem was discovered more than 10 years ago, but solutions took time.
He backed Hunn Report co-author David Kernohan, who said that after 10 years, little had changed.
Home Owners and Buyers' Association chief executive Roger Levie, working with owners of hundreds of rotten units, is planning demolition and rebuilding on the valuable sites.
Mr DeLeur said the building industry had come a long way and the introduction of new standards, treated timber and new compliance documents had changed how buildings and cladding systems were constructed.
"Comments that buildings constructed today still leak are misleading in the sense that historically buildings have always leaked," he said, answering Mr Levie's claim that a third of the 15,000 new houses built annually needed repairs.
"It is how those leaks are managed that is the mitigating factor - changes have occurred in the design of our building systems, the introduction of treated timber."
Last year's introduction of the Licensed Building Practitioner scheme and further changes would bring a progressive transformation.
But he took issue with Mr Levie's saying the council was not doing enough to encourage people to act before the 10-year limitation period.
Mr DeLeur said there had been widespread publicity about leaky houses through the media and the introduction of the Weathertight Homes Resolution Service Act and the Weathertight Homes Tribunal.
Councillor Cameron Brewer wondered if the council had done enough to help victims of the $22 billion scandal.
"The council has allocated $487 million of borrowed money towards paying out leaky home owners over the next 10 years.
"I would hate to think it is making good ratepayers unnecessarily sweat if they've already jumped over all the hurdles and gone through all the many necessary hoops to secure Government and council support."By Anne Gibson @Anne Gibson Email Anne