John and Glin Esling are North Shore leaky-building victims whose lives have been ruined in the past six years.

In 2004, the couple bought a unit at 1/7 Andersons Rd in the Oteha Valley area. At the time, they were based overseas but thought the townhouse was fairly new, low-maintenance and a good short-term residence.

Instead, the place leaked so much an upper balcony had to be removed and Mr Esling said the complex suffered severe failings.

"Water gushed into some parts and walls have begun to separate from rotten timber framing.

"It became apparent there was water coming down in behind the walls," said the disillusioned retired surveyor, who is in his 60s.

"This is a complete cancer on our society. It's depressing because you have an asset which is actually a liability. How the hell can we be rated on properties that have very little intrinsic value?" asked the $1500-a-year ratepayer.

Owners who paid about $400,000 would now be lucky to recover $200,000, he estimated.

He is being represented by lawyer Adina Thorn at leaky-building specialists Hoskins Thorn.

She is acting for the body corporate and seven of 11 owners and said the Eslings' unit and others needed extensive repairs including full recladding.

Some areas around windows revealed dangerously high moisture readings at about 100 per cent, she said.

"The Eslings have suffered considerably," she said. She picked up the couple's case after they went to the state's Weathertight Homes Resolution Service but one party, a developer, sought successfully to have the case transferred to the High Court.