St Leonards Catholic School in Durham will be rebuilt to the west of the school site, replacing the existing disused and RAAC-affected buildings once demolished.
The 110,000 sq ft three-storey school will include sports, assembly and dining halls and a wide range of departments, including specialist teaching spaces for art, technology and music at ground floor level.
The existing Springwell Hall will be reconfigured, refurbished and utilised as part of the redeveloped campus. The existing Sixth Form building will also be retained.
Ryder Architecture designed the new school that was originally expected to cost around £46m to deliver.
The new building is hoped to be ready for occupation during 2026.