The new 110,000 sq ft, three-storey Deyes High School in Maghull will consist of over 60 classrooms, and other facilities, such as a main hall, sports hall, dining and kitchen areas and a part-covered multi-use games area.
Once the £36m building is in operation, all the original buildings, apart from the current sixth form block, will be demolished.
Sustainable design features include a full Biosolar green roof, solar panels, and high performing thermal insulation and passive ventilation solutions.
Air source heat pumps will be installed and there will be no dependency on fossil fuels for heating or hot water.
Sean Fenner, regional director at Kier Construction North & Scotland, said the new teaching building would complete in spring 2024, followed by external works completion in the spring 2025.