Willmott Dixon has started work on the prestigious contract to revamp and expand the Royal Welsh College of Music and Drama in Cardiff.
It beat rival contractors Sir Robert McAlpine, Bam Construct and Carillion to the £22.5 million job.
The project will see the construction of a 450-seat concert hall, a 160-seat theatre, drama rehearsal spaces and an exhibition gallery.
The new facilities, set for completion in early 2011, will link to the existing buildings to create a new landmark entrance to Cardiff from the North.
Past students of the college have gone on to ply their trade in theatres, concert halls, films, TV and radio across the world. Famous alumni include Anthony Hopkins, Peter Gill and Michael Forrest.
Willmott Dixon Wales managing director Neal Stephens said: “The new buildings will further enhance the college’s reputation as a fantastic destination for students, staff and visitors.
“We will be working with the college to ensure minimum disruption and inconvenience for all involved.”