Vale of Glamorgan councillors have criticised the government for not coming up with more cash. Education and lifelong learning minister Jane Davidson said it will be providing pound;13 million over the next three years, in addition to pound;5.6m since 2002-3.
The council is planning to redevelop St Cyres, Cowbridge and Llantwit Major secondaries. The first is spread across two sites and the second across three.
Problems with the schools include old and leaking temporary classrooms and rotting buildings. A phased programme of work over 10 years could start at Cowbridge as early as next spring.
The council is increasing its borrowing and using education funding for the project, along with grants from the Assembly government, and receipts expected from the sale of surplus school sites.
But it estimates it is still pound;15m short of the pound;68m needed for the three secondaries and other school improvements.