The project was initially expected to start more than 12 months ago and was originally estimated to cost around £40m before inflation impacted the industry.
Entirely funded by the Department for Education, Yeovil College campus will be redesigned and developed over the next four years.
Bath-based groundwork contractor Pennys has started work on site.
The footprint of the newly-developed site will comprise 12,500 sq m of new build development, replacing 8,800 sq m of demolished buildings taking overall campus building space to 21,700sq m.
The project includes a new sports centre, a technical construction centre, and a large teaching centre, which will house all commercial outlets, including re-envisaged salons and restaurants, as well as much of the teaching space from across the curriculum.