A "Help Save the Regent" campaign spearheaded by The Star community newspaper reached its $2 million target last week.
The Dunedin City Council had agreed to provide $2.7 million for initial work if the Otago Theatre Trust could raise $2 million.
However, Regent Theatre manager Sarah Anderson said this week up to $1 million still had to be found for "non-urgent" work.
"The Star campaign went really well but, when the job was originally priced, some expenses were not accommodated for," she said.
"We carved off some expenses so we could fit in the $6.9 million budget. Things that are non-urgent, like painting the auditorium and fitting out the dressing rooms. The dressing rooms will be functional, but not palatial. So, we're still fundraising for an extra $750,000 to $1 million to cover that."
The auditorium would also be repainted and recarpeted, new seating installed and fire protection systems renewed, she said.
The main redevelopment project includes rebuilding the stage area to incorporate a modern 65-line counterweight fly system and tower for hauling stage scenery, increased basement and storage areas, new dressing rooms and a larger orchestra pit.
Chairman Michael Shield said refurbishment work had already started.
"We're absolutely thrilled with how the whole community's got behind us and supported the Regent.
The work on the flytower is going on now while we've got some down time and there are no shows on," he said this week.
"That way, we'll save a few weeks of work when the theatre closes in October."
The theatre will close for refurbishment after the Otago Festival of the Arts, on October 20, and reopen in July next year.