Owners of leaky buildings with fibre-cement products Harditex and Titanboard have been given High Court permission for a representative class action against building materials firm James Hardie.
The case could involve repair bills totalling $25 million.
The group has also secured an opt-in period for those who have not already issued proceedings.
Lawyer Dan Parker, who was taking the proceedings, said it could be the last chance for similarly affected owners wanting compensation for the defective products.
Mr Parker is representing more than 80 property owners: 19 for the Titanboard claim, and more than 60 for the Harditex claim.
But others could still join the class action if they opted in within the next two to 10 weeks, depending on the type of claim, he said.
Mr Parker said the claimants all faced hefty repair bills.
"You've got the same issue of people basically living in their home, suffering these issues and significant repair costs. And, you know, an expensive process to run as well."
Last December, Parker & Associates added the 19 commercial units whose owners alleged negligence and breach of the Fair Trading Act in relation to Titanboard.
The claimants say James Hardie was negligent in the design, manufacture and supply of the Harditex and Titanboard cladding systems.
The group is pooling resources to pay for the litigation.
Thousands of properties were built using Harditex and/or Titanboard through the 1990s and early 2000s.
In July the Supreme Court dismissed building product manufacturer Carter Holt Harvey's appeal over a Ministry of Education claim the company was liable for the cost of fixing about 890 leaky schools.
The judgement found that claims in relation to defective building products could be argued, and would not be subject to the 10-year limitation under the Building Act.
In December 2015, a separate $250 million class action claim was filed in the High Court in Auckland by Adina Thorn Lawyers on behalf of the owners of more than 1000 units and houses.
A court hearing in relation to that claim will take place in November to see if it can also be heard.
James Hardie denied the allegations.