In March, when the Ministry of Justice announced a deal had been struck with the council, and the courthouse would reopen under the council's ownership, Waitaki Mayor Gary Kircher said he hoped the 132-year-old courthouse would again serve as the Oamaru District Court within the year.
Yesterday, he said there were some factors that might delay the start of the work in July.
"Ideally, we want to get things under way,'' Mr Kircher said.
"There's a strong desire on our part and on the community's part to get hearings back into the courthouse as soon as possible. And so, the sooner we start work, the sooner they will get back in there - out of the porta-court and into the real courthouse.
"Obviously, work's happening now, physical work ... There's a wee bit of time. And there's a few unknowns yet.''
The courthouse, in Lower Thames St, was identified as requiring earthquake-strengthening and closed in November 2011.
The criminal court was initially transferred to Timaru, before transferring in 2012 to the Oamaru Opera House.
In 2014, it was relocated again to the so-called "porta-court'' in Humber St, where it remains.
Two ministry estimates for the cost of strengthening work, an initial estimate of up to $6million and a later one of $2million, seemed to put the work out of reach.
The ministry said it was too great a cost for a court that operated less than a day a week on average.
The community and the council disputed the costs and the ministry agreed to transfer the court to the council - for a nominal fee of $1 "if demanded'' - and the ministry would lease the building for court services for a 10-year term.
Oamaru engineer Michael Forgie's engineering report and costings estimate, which was under way, might be required to be peer-reviewed by the ministry, Mr Kircher said.
And the council had had only "initial discussions'' with Heritage New Zealand, which would be involved in the process.
Although in March Justice Minister Amy Adams announced the council had decided to strengthen the courthouse to at least 67% of the new building standard, this week, council chief executive Michael Ross said the work under way would provide the council with plans to strengthen the building to 100% of new building standards "in the interests of the long-term future of the building''.
He expected the difference in cost to be minor, he said.
The costs incurred by the council to strengthen the building would affect the deal struck with the ministry.
"The actual lease has yet to be prepared,'' Mr Ross said.
"The lease amount will be based on the costs to upgrade the building, which we are yet to confirm.''
