One in five people working on future NSW infrastructure projects will be apprentices, the state government says.

The measure aims to create at least 4000 more apprentices over the next four years, Premier Gladys Berejiklian told reporters in Sydney on Thursday.

Despite 20 per cent of workers being apprentices, Ms Berjeiklian said it was not a cost-saving measure and would not save the government money on projects.

Deputy Premier and Skills Minister John Barilaro said “there is no doubt this program will have a generational impact on workers who will be able to tell their families ‘I got my start in life on a NSW government project'”.