Patsy Inder said the Ministry of Education confirmed an $8 million upgrade, which would take place over four or five years.
"While we are excited about the news, it will be a long time before the cogs start turning.''
Finalising the design would take a while and construction was likely to begin next year, she said, "but we're not sure exactly when''.
The school's roll was "reasonably steady'' at 180.
"It was much bigger in the '70s. We have suffered from rural decline like everyone else has.''
The school would be able to repay the community's ongoing support with "up-to-date facilities''.
"We need buildings that can handle the Central Otago climate, the heat of summer and ice in the winter.''
Better insulation and electrical systems were high on the priority list, she said.
"We want buildings that utilise the sun but can also block out glare, facilities that work for 5 to 18-year-olds.''
Ms Inder said she hoped the school would be completely rebuilt.
"The current buildings were great for the 20th century but we're 16 years into this century.''
The ministry proposed spending between $8 million and $8.5 million but it could cost more, she said.
Board of trustees chairman Dave Hutton-Atkins said the rebuild would give the children a feeling of pride.
"We'll get a school that's fit for the community.''
The board had recognised the school's need for an upgrade for a while, he said, "but we didn't think it would be anything to this extent''.
There were too many buildings for the number of pupils so some condensing would be needed, he said.
Ministry of Education head of education infrastructure service Jerome Sheppard said it was working "very closely'' with the school and its community to develop a plan to address property issues.
"Most of the buildings are between 40 and 60 years old, and are becoming difficult to maintain.
"We would expect to have more details about costs and timeframe later in the year, depending on when detailed plans can be finalised and approved,'' he said.
