Parents are furious that plans to move Chatswood Public School to a bigger site have been dumped even though the school has had to ban handball, hold four separate assemblies and stagger lunchtimes to deal with the "severe" overcrowding.

The Parents & Citizens Association has also been paying $10,000 a year to have the school's toilets cleaned between recess and lunch because of pressure on the facilities, which they say have not been upgraded despite a 54 per cent increase in enrolments since 2012.

Year 2 students Ashleigh Ho and Victoria Spencer outside Chatswood Public School. Credit:Louise Kennerley

School Infrastructure NSW earlier this year announced plans to build a kindergarten to year nine education precinct on the bigger Chatswood High School grounds, and a year 10 to 12 campus on the smaller primary school site.

But last week parents were told that idea had been abandoned. Under a new plan, both schools will get upgrades but remain on their own sites. The department would begin looking for somewhere to put a new school.