Christchurch has officially opened a transitional cathedral made from cardboard in Latimer Square, replacing the neo-Gothic structure destroyed in a 2011 earthquake that killed 185 people in New Zealand's second largest city.

Completion of the innovative structure, designed by Japanese architect Shigeru Ban, marks a major milestone in the city's recovery from the devastating magnitude 6.3 quake that levelled much of the downtown area, acting dean Lynda Patterson said.

"The old cathedral symbolised the city in many ways and we think this cathedral is a symbol that Christchurch is regrouping and rebuilding," she said.

"The community has a cathedral again. It's a place where people can come for quiet contemplation in the city centre and somewhere we can hold concerts and art exhibitions."

Built from 600-millimetre diameter cardboard tubes coated with waterproof polyurethane and flame retardants, the cathedral is a simple A-frame structure that can hold 700 people.

Despite the unusual building material, it has a design life of 50 years, with the Anglican Church planning to use it as a cathedral for at least a decade while it builds a permanent replacement for the late 19th-century building lost in the quake.

It has a concrete base, with the cardboard tubes forming two sides of the A-frame and containers helping brace the walls.

One end of the cathedral will be filled with stained glass and a polycarbonate roof will help protect it from the elements.

It is the most ambitious piece of "emergency architecture" attempted by Mr Ban, who has forged a reputation for using low-cost, easily available materials to build structures in disaster zones from Rwanda to his native Japan.

In an interview with AFP last year, Mr Ban said cardboard was a surprisingly strong building material and described projects such as the cathedral as part of the "social responsibility" of being an architect.

The project has not been without setbacks. It was originally slated for completion in November last year and the budget has reportedly increased from NZ$4.5 million ($3.9 million) to around NZ$7.0 million ($6.1 million).

Last month, some sections of cardboard tubing became sodden when a torrential downpour hit before the roof was completed, although they were swiftly cut out and replaced.

Ms Patterson said it was a relief to finally stage the building's dedication service on Thursday evening.

"I still keep having dreams that the ground has shifted and I'll go there and it's a building site again," she said.

She added that reaction to the cathedral from parishioners and the public had been "overwhelmingly positive".

"From time to time we wondered if we'd ever get there," she said.

AFP