NSW Premier Gladys Berejiklian has defended her government's education infrastructure plan amid claims it isn't keeping up with Sydney's burgeoning population.
As more than 800,000 students began to walk through the school gates on Tuesday, Ms Berejiklian and Education Minister Rob Stokes visited the newly-built Wentworth Point Public School in Sydney's west.
It was an example of the 1500 classrooms to be delivered through new or upgraded schools in the next four years, the premier said.
Opposition Leader Luke Foley claims NSW is in "crisis", with an additional 280,000 students needing classrooms over the next 15 years.
But Ms Berejiklian said there had already been a net increase of 600 classrooms since her party formed government.
"We're able to do this because we've worked so hard to have a strong budget position," she told reporters.
"We've done a lot so far but we're re-doubling our efforts over the next few years."
The Wentworth Point school has also been criticised because classrooms are not air conditioned.
Mr Stokes said the site used passive design principles and its waterfront location to help ease the heat's impact in summer, referring to it as "deliciously cool".
"As and when air conditioning is required, of course we will look at it and we have a clear policy in relation to its provision," Mr Stokes said.
Ms Berejiklian said the government had inherited policies that dictated when air conditioning should be installed, including a school's location, average temperature and demographic.
"This is part of good sustainable development which will last us another century," she said.
The Wentworth Point project took longer than anticipated due to remediation works on the site and local government approvals, Ms Berejiklian added.
New syllabuses in English, mathematics, science and history will be taught for Year 11 students in 2018.