The Health and Safety Executive prosecuted Sherborne School and Peter Eldridge, the director of a company responsible for the refurbishment project, after an investigation found they had failed to identify and prevent the risk of asbestos exposure.
Dorchester Crown Court heard how insulation boards were removed in an unsafe way, exposing building contractors and a teenage work experience student to asbestos fibres.
The HSE investigation found that from the initial design stages in May 2008 right through to undertaking the construction work in July 2009, there was inadequate planning and a failure to carry out a full asbestos survey.
Samples taken from the building in 2008 had identified the presence of asbestos and it had previously been removed from other parts of the school.
The court heard that neither Eldridge nor the school had appointed a CDM coordinator for the refurbishment project.
Sherborne School was found guilty of breaching safety regulations and was fined a total of £60,000 and ordered to pay £13,000 in costs.
Eldridge, of Sherborne, Dorset, was also found guilty of safety breached and was fined a total of £10,000 with costs of £6,000.
Speaking after the prosecution, HSE Inspector Joanna Teasdale, said: “Both Peter Eldridge and Sherborne School knew about the risks posed by the presence of asbestos in the school buildings, and yet they failed to manage the risk of exposure to asbestos fibres during the refurbishment project.
“As a result several people, including at least one teenager, were put at unnecessary risk. In being exposed to asbestos fibres they could develop a serious and potentially fatal illness.
“Although Sherborne School was the client, it still had a duty to manage the control of asbestos on its site, and to be aware of the requirements of removing asbestos safely.”