More than a hundred applications have been made to a proposed class action targeting the makers of faulty steel mesh in concrete floors.
The legal action by Auckland's Adina Thorn Lawyers, with backing from a London law firm, aims to gather claims of more than $100 million.
The lawyers say several international insurers have advised the seismic mesh could compromise insurance policies, by calling into question whether homes are compliant with the Building Code.
Adina Thorn said hundreds of homeowners from across the country had signed up.
"We're building the class, and if the class is big enough there's going to be a funded class action against a number of steel manufacturers and suppliers across New Zealand.
"Obviously there has to be a certain viability to be able to be funded, but at the moment it's looking good."
Ms Thorn said people uncertain of whether they are eligible for the class action should register and let her inspectors make a judgement call.