Government schools in Canberra's north are more likely to be short for space, while deep in the city's south schools are running well below capacity, an annual census of ACT schools shows.
The number of school students in the ACT has continued to expand with the territory's population, with 78,752 students enrolled, up 2.10 per cent from last year.
Growth has been strongest in independent schools, with enrolments up 2.55 per cent. Government schools saw increases of 2.51 per cent.
Catholic sector growth has been slower, with enrolments only increasing by 0.23 per cent overall.
A spokesman for the education directorate said the ACT government expected enrolments to grow about 3 per cent every year for the next decade, with urban infill programs driving growth in established schools.
Lyneham High School is the only school in the ACT to be oversubscribed, with 101 per cent of places filled. The census showed 1101 students enrolled.
Twelve schools operate are more than 90 per cent full, down from 15 schools in 2018.
Canberra College, with 976 students enrolled, is operating at 96 per cent capacity. Canberra College Cares, which shares the same site, is running at 77 per cent capacity.
In the city's south, Gilmore Primary School, which had 110 full-time students in 2019, is the second least-subscribed school in the ACT. It is running at 35 per cent capacity.
At its peak, the Tuggeranong school had more than 800 students between kindergarten and year 6 but as Canberra's young population has shifted to the north, enrolment levels have fallen.
Only Margaret Hendry School, which opened in Taylor earlier this year, is running at a lower capacity in the ACT, at 24 per cent.
Six of the 10 schools running at the lowest capacity are located in Tuggeranong.
The executive director of the Association of Independent Schools of the ACT, Andrew Wrigley, said the sector was "delighted parents are choosing independent".
"There is great education in all sectors. But my position has always been that parents should be active in the choice of school," he said.
Mr Wrigley said the challenge for the sector was ensuring schools could manage capacity and there was interest from the sector in more land for new independent schools.
Independent schools attracted students from all over Canberra so there wasn't a consistent pattern of capacity need, Mr Wrigley said.
The census does not include capacity data for independent and Catholic schools.
ACT Council of Parents and Citizens Association president Kirsty McGovern-Hooley said small school communities were often very proud and enjoyed better access to their principals and school leadership teams.
"It goes back to that original idea of Canberra schools being small and community based. The parents would reflect they the accessibility to the principal, that they knew everybody, that they had a really great community feel in those schools," she said.
"[The parents] just felt that had been a really great advantage."
Ms McGovern-Hooley said there was opportunity to engage communities with under subscribed schools to make better use of them as community hubs, but the education directorate had overestimated the potential for growth in Canberra's south.
An education directorate spokesman said there were "strong indicators of future growth in Tuggeranong as well as in other areas where schools currently operating at lower capacities are located".
Chief Minister Andrew Barr said on Friday that there was no need for another "difficult" round of school closures. He oversaw the last round as education minister in 2006.
The director of Catholic education in Canberra and Goulburn, Ross Fox, said Catholic schools had also seen the same pattern of growth in the north and schools running below capacity in the south.
Schools running below capacity was not necessarily a bad thing and could allow more flexibility with teaching spaces, he said.
"Additional enrolments allow you to consider additional curriculum offerings and programs within your schools. We're always willing to welcome families," Mr Fox said.
"If you're not running at capacity, it does give you some flexibility with things like music rooms, learning support and other creative use of spaces - whether it's for language programs or technology maker spaces, which are very popular."
MORE EDUCATION NEWS
The sector was keen to work with the ACT government to identify more land in the city's north to cater for growing demand, he said.
Despite sluggish growth in the Catholic sector overall, Mr Fox there had been a strong vote of confidence in the sector with a 5 per cent increase in kindergarten enrolments and an 8 per cent increase in year 7 enrolments.
The education directorate said there was strong indication schools running below capacity would see growth.
"These indicators include notable increases in enrolments from 2017 through to 2019 and higher enrolments in cohorts in the entry years," a spokesman said.
"Demographics in our suburbs change over time, which has an impact on enrolments at our schools. This, along with individual family preferences, such as school locations, will differ from school to school."
Correction: A previous version of this story said wrongly that Canberra College was the ACT's most oversubscribed school, operating at 112 per cent capacity. It is operating at 96 per cent capacity. This was the result of a data-matching error.