NSW's private schools may soon be able to build classrooms, childcare centres, gymnasiums and lecture theatres as high as 22 metres on their grounds under a fast-track development process, which critics say lacks transparency and accountability.

The proposal is part of a suite of reforms announced by the NSW Government in a bid to encourage the private sector to absorb some of the demand on the overcrowded public school system, which is expected to accommodate a further 170,000 students over the next 15 years.

Private schools may be able to build classrooms,gymnasiums and lecture theatres as high as 22 metres on their grounds. Credit:Michele Mossop

Announcing the reforms in February, Education Minister Rob Stokes said the policy package would streamline the planning approval process and "make it easier to deliver well-designed, high-quality schools where they are required".

At least 15 councils across Sydney have raised objections to the reforms. Their criticism centres on key measures that will allow private schools to build millions of dollars worth of new buildings either without development approval from councils, or through a fast-track pathway of "complying development".