Nelson's mayor says the cost of strengthening the city's main entertainment venue could run to more than $27 million.
Rachel Reese says detailed reports indicate that could be the final figure of ensuring the Trafalgar Centre meets at least 67 percent of new building standards.
The sports and entertainment venue was closed in November last year due to fears of a high loss of life in the event of a moderate earthquake.
The city council has held numerous meetings in the past few months to decide how to proceed, and no final decision has yet been made.
Ms Reece said though the council still has a lot more to discuss, if the overall repair bill is estimated to be close to $27 million, the council would be forced to consider other options including closing the centre permanently.
Engineering and legal reports are being made available for the public to view on the council website.