Battle against alleged leaky homes giant James Hardie inches one step closer

David has landed a significant hit on Goliath in the leaky homes legal battle, with the Supreme Court ruling that the Australian parent company of James Hardie will be included in a class action against the building supplies giant.

Affected Kiwi homeowners say it takes them one step closer to the $250 million of compensation they say they're owed.

One of those homeowners is Lesley Wheatley who says seeing the inside of her Auckland apartment, riddled with rot, is a moment she'll never forget.

"When they take the cladding off all you see is blackened timber that you can poke your finger into, or it will just crumble away," she told Newshub.

"[There are] no words... and then James Hardie's name is at the top of the list of all the bad words. Just how did this happen?"

In a North Shore suburb later dubbed 'Leaky-homes-ville', Wheatley's was one of 14 timber-framed buildings in the block that suffered weather-tightness issues.

It's one of thousands across the country.

"I'd rather be diagnosed with cancer again," she said.

"It was financially devastating, the trauma of going through all this. You can't imagine."

The crisis, which began in the late '90s, has led to a long legal battle.

Adina Thorn has spent years fighting building supplies giant James Hardie, battling for closure.

She alleges their products were faulty and caused the leaks, which led to life-threatening mould.

"Everybody has a friend [or] a family member that's affected by this," Thom told Newshub.

"This is a national disaster and we're calling this company to account."

And with the Supreme Court now ruling to include the parent company in the class action, there will be no more delays going forward.

"These people haven't recovered. They are minus $300,000, $400,000, $500,000. This is not something you can fix in a lifetime."

The case against James Hardie is estimated to be worth $250 million and the owners of the 14 units at 'Leaky-homes-ville', who were all caught up in the saga, would each be eligible for a portion of that pay-out.

The legal action involves more than 365 buildings and around 1000 people - people like Wheatley, who are only just now starting to see the light at the end of this nightmare.

"We survived, that's how I feel," she said.

"We've been through it, we survived."

And by next year, they hope they'll be compensated, too.