The boss of the design firm behind the CTV Building, which collapsed in Christchurch's February 2011 earthquake killing 115 people, has been granted an appeal in a long-running saga over whether New Zealand's professional engineering body should have pursued disciplinary action against him.

The Institution of Professional Engineers (Ipenz) lodged a complaint in December 2012 against Dr Alan Reay of Christchurch design firm Alan Reay Consultants which was responsible for designing the ill-fated six-storey Christchurch office block.

A Royal Commission of Inquiry into the Canterbury earthquakes had earlier criticised Reay for giving his inexperienced structural engineer David Harding "sole responsibility" for the building's mid-1980s design.

Ipenz decided it could not continue with disciplinary proceedings against Reay after he resigned his voluntary membership of the institute.


But in March last year, the attorney-general appealed that decision to the High Court.

In December last year, the High Court at Wellington largely granted the attorney's application to strike out parts of Reay's statement of defence.

Reay then appealed that decision to the Court of Appeal.

In a new judgement released today, appeal judges Randerson, Wild and Winkelmann decided that Reay's appeal will be allowed.

Lawyers for both parties have agreed to lodge amended documents to the High Court setting out their respective cases.

The attorney-general must now file an amended statement of claim by no later than November 11, while Reay has until November 25 to file a statement of defence to the amended statement of claim.

"As this court has several times emphasised, judicial review is intended to be a simple and straightforward procedure enabling the court to give a decision with the requisite speed," the appeal judges said.

The Government last year announced it is looking to strengthen the regulation of engineers to "ensure they have the right knowledge, skills and competence" to design safe buildings and to hold them more accountable for substandard work.