Vale of Glamorgan Council aims to completely rebuild Pencoedtre High School and eventually cater for up to 1,250 pupils by 2026.
Bouygues plans to build the new school campus alongside the existing school, which will be demolished after the project is finished in 2021.
The 130,000 sq ft school building will rise to three-storeys at the main building with a dining hall, main hall and courtyard, a sixth form area, an all-weather sports pitch and games courts.
Architect HLM designed the school with Hydrock providing M&E, fire and acoustics design.
The site is in close proximity to both Whitmore High School and Ysgol Gymraeg Bro Morgannwg, both of which have recently received planning approval for redevelopment and extension proposals.
Morgan Sindall Construction will start work soon on the £29m Whitmore High School project, while ISG has started the £19m expansion of Ysgol Gymraeg Bro Morgannwg in Barry.