Disciplinary action can now be taken against the engineer whose company designed Christchurch's CTV building.
The building has become a symbol of the February 2011 earthquake - when it collapsed and killed 115 people.
Today the Court of Appeal ruled Engineering New Zealand can continue disciplinary procedures against the owner of the engineering firm that designed it.
Alan Reay's firm designed the Canterbury Television building in 1986. He was the sole practitioner and a very experienced engineer.
But Reay was accused of letting an inexperienced employee, David Harding, complete much of the structural design, with very little supervision.
Disciplinary proceedings against him were quickly dropped.
Reay had resigned from the governing industry body, Engineering New Zealand - which was previously known as the Institution of Professional Engineers.
In December the High Court ruled Engineering New Zealand made a mistake when it decided it had to dismiss disciplinary proceedings against him due to his resignation.
Reay was quick to file an appeal against the decision - with his lawyer announcing it had been lodged in February.
It's now been overturned.
Engineering New Zealand has welcomed the Court of Appeal decision, with chief executive Susan Freeman-Greene saying it will continue its complaints process against Reay.
"We restarted our complaints process after the High Court decision in December, ahead of the outcome of this appeal. We can now continue that process," she said.
"It's really important this a fair, robust and transparent process that determines whether there are professional disciplinary issues.
"The investigation into the complaint about Dr Reay is currently at the Investigating Committee stage. The role of the Investigating Committee is to determine whether there's a matter to answer."
Freeman-Greene said if the complaint then proceeds to a Disciplinary Committee, the hearing would be open to the public.