Guernsey’s States has approved the final version of the new model for secondary education by 23 votes to 15.
The island will operate a “one-school, two-site” system from 2021, rather than the current system of four schools.
The total cost of the transformation is expected to be up to £157m, with approximately half of the cost being spent on developing the two campuses.
Deputies also agreed to conduct a review of special educational needs and disabilities provision.
The new funding structure included £77.9m for redeveloping the sites, £51.1m for the specialist further education facility at Les Ozouets and up to £22.4m for renovations to La Mar de Carteret Primary School.
The two sites of the combined institution will be developed at the sites of current secondary schools, Les Beacamps and St Sampsons High School.
The name of the new school, Lisia, was announced in July.