Carpentry, plumbing and painting teachers at NSW TAFE are being made redundant at one of the state's largest institutes despite a nationwide shortage of apprentices, internal documents obtained by Fairfax Media reveal.

The move comes as the state government's vocational education restructure pushes the training of apprentices on site while core trades move towards the scandal-plagued private sector.

According to the "change management" documents drafted in April, five carpentry teachers will lose their role at the South Western Sydney Institute. They will follow three glaziers, four painters and six plumbers, who were notified of their redundancies last year.

"There is a need to operate in a business model where there is a focus on generating revenue through commercial opportunities, using resources efficiently, identifying innovative responses to customers and reducing reliability on government funding," the documents state.