A new Education Department audit has found New South Wales schools have a maintenance backlog of more than half a billion dollars.

The latest audit — to be released later today — reveals planned maintenance costs have fallen from a projected $775 million in June 2016 to $570 million in December 2017.

Premier Gladys Berejiklian said the Government had cut outstanding maintenance work by more than $200 million after inheriting a billion-dollar backlog from Labor.

"In the last 18 months we've reduced the backlog by quarter of a billion dollars," Ms Berejiklian said.

"There is more work to be done of course, but we have the resources and we've dedicated those resources."

Education Minister Rob Stokes said a blitz addressing issues including floor and roof upgrades and painting had helped slash the backlog.

"The NSW Government's record school maintenance investment is having a real impact in addressing long-term maintenance challenges," Mr Stokes said in a statement.

The audit did not include any maintenance issues that posed a safety risk to students or staff.

The Government said any broken items in classrooms that impacted on teaching and learning were addressed as a "matter of priority".

Opposition education spokesperson Jihad Dib said the problems still had a negative impact on learning, and repairs should be prioritised.

"Imagine trying to learn or work in an environment that's got peeling paint, windows are broken the fans don't work, the carpet is threadbare that the toilets don't flush properly," Mr Dib, a former principal, said.

"Maybe these aren't considered major problems, but they are an overall problem and they do send a message that public education isn't valued."

He rejected claims Labor accumulated a billion-dollar maintenance list.