Argyll and Bute Council is leading the work, which aims to transform the school into a modern site whilst maintaining its listed building status.
The new west wing of the school will open to pupils next week, Wednesday 14 November.
The next phase will see the demolition of the east wing and formation of a new part.
When the full project is complete the school will provide capacity for up to 300 pupils and 30 early learning and childcare places.
It will also house a new family centre, gym hall, library, early learning and childcare centre, and staff accommodation. A link will be made to connect the refurbished west wing to the new east wing, with a feature staircase.
-- Advertisement --
Welcoming the news, the Council's Policy Lead for Education, Councillor Yvonne McNeilly said: "We want the very best start for our young people, and I am in no doubt that this phase in the wonderful new state-of-the-art facility will help us to provide that.
"Not only will it enable pupils to realise their full potential, but it will enable them to really enjoy their learning experience. Our vision is that we will realise ambition, excellence and equality for all. This new school will help our young people to achieve that.
"I wish all the staff and pupils the very best of luck and many happy years of learning and look forward to completion of the next phase."
hub North Scotland Chief Executive, Michael Padzinski added: "We are delighted to successfully reach this important milestone in the work to create an excellent facility for teaching and learning. We look forward to continuing to work in partnership with Argyll and Bute Council to achieve the next phase of this exciting project."
(CM)
