Christchurch's new stadium could be a 25,000-seat $496m venue with a retractable pitch, according to a new report.

Photo: Christchurch Stadium Trust

The feasibility study by the Christchurch Stadium Trust, established to manage the stadium, details four options for a multi-use arena next to the central city.

A blueprint for the new stadium was drawn up in 2012 as part of the earthquake recovery plan, and the original idea was to have a 35,000-seat covered arena with a retractable roof.

But the trust's study found that option would be too expensive, and too big.

Read the full report here (PDF, 5.8MB).

The report instead detailed four other options with the cheapest, at $368m, catering for 25,000 people and having a roof covering up to 80 percent of the venue.

The most expensive would have 30,000 permanent seats, a solid roof and retractable pitch, with a price tag of $584m.

But the preferred option was a $496m stadium, which would have 25,000 permanent seats, a solid roof and retractable pitch.

The city council has already promised a quarter of a billion dollars for the project, which would take more than five years to build.

Despite the report's conclusions, Greater Christchurch Regeneration Minister Nicky Wagner said cost was not the most important element in the choice of a new stadium.

She said while cost was a factor, the design of the stadium must be flexible enough to host sport, concerts and exhibitions.

"A covered roof gives more options, but if you can remove a retractable pitch, which is a new technology that has been used overseas, not used in New Zealand, that also means you can also have not only turf-based activities, but also hard-floor activities."

Christchurch mayor Lianne Dalziel said the city would get the most versatility from the preferred option, but additional funding would be needed.

Ms Dalziel said the council had committed $253m to building a new arena, and other funding partners would need to be found.

Canterbury Rugby Union chair Trevor McIntyre said while it was an expensive facility, it was what the community wanted and would help to make Christchurch an international destination.

Mr McIntyre said he did not believe the Canterbury Rugby Union should have to contribute to the building costs.

Construction could start at the beginning of 2019.

The study was commissioned by the government and the city council.