"Conditions are awful. The children and staff have to put up with an awful lot - the doors are coming off and the ceilings come down," BBC quoted headteacher Lyndsay Bradley, as saying.
Architects behind the new building, dubbed the 'Weetabix school,' claim that the high quality of insulation will mean that the body heat of the children will help keep the building warm.
The timber superstructure is coming from Austria.
Highland councillor Michael Foxley said it would be the most sustainable school in Scotland, but conceded it would not be cheap to build.
"The difference between this type of building construction and others is that has a high level of energy insulation, which creates a very safe non-toxic environment for people to live and work in the building," he said.
"It's not a cheap project because of its location, but it is a forerunner of future sustainable projects from which we will learn a lot.
"There is currently no capability within Scotland to produce this type of mass timber construction," he added.
However, the councillor hoped the capability could be gained locally to create jobs in the future.
Architect Sam Foster said that the buillding is being constructed from environmentally-friendly materials.
"The building itself has been designed to be incredibly efficient. It's very well insulated and airtight, which stops heat getting out," he said.