The school was targeted by arsonists in 2000

The council's initial designs for Lytchett Minster School in Dorset had to be changed after it was found they would cost up to �2m over budget.

Independent architects have also said the designs did not fit in with the existing Grade II listed manor house.

Pupils have been taught in temporary classrooms since the arson in 2000.

'Other schools benefit'

The school's revamp has been delayed before when a rare protected tree was found at the site.

Dorset County Council says it hopes that designs for the maths, science and humanities block will go before its planning committee in the Spring.

Toni Coombs, the council's cabinet member for children's services, said: "We understand that everyone at Lytchett Minster School wants to have the new teaching block in place as soon as possible.

"However, we have agreed that officers should step back and take a fresh look to find a solution that successfully marries educational requirements and site constraints.

"It is important for us to keep the cost of the project within the agreed budget so that other Dorset schools can also benefit from new investment in modern school buildings."