Scaffolding will go up around the site and a crane will lift roof slates out of storage this week in preparation for roof renovations beginning in mid-September.
Dunedin Prison Trust chairman Owen Graham said the trust was grateful to get to a point where the second stage could begin, replacing the old slate roof with more than 15,500 new slates and completing exterior repairs and refurbishment of the cellblocks.
"Earlier in the year, with the city and country in Covid-19 lockdown, plans to get the $660,000 restoration project off the ground seemed unlikely.
"But thanks to the support from funders and a strong sense of doing right by local contractors in these challenging times we [the Dunedin Prison Trust] are about to start the restoration works."
While the trust was still awaiting decisions on securing the final $115,000 of funding to complete the second stage, "we have reached the point where we needed to commit to this project now", he said.
It also hoped to reinstate the two front gate pillars.
The project was expected to take until mid-March next year to complete, Mr Graham said.