On Thursday, 175 students from kindergarten to year 6 arrived for their first day. This year, there will be one class each for years 1 to 6, while the 40 kindergarten students will have two separated class groups.

College principal Paul Humble was not expecting such strong enrolments.

"I was always going to be cautiously optimistic but there's been just such a fabulous uptake and interest from the community and not just our local community but from all over the region," Mr Humble said.

Unfortunately, the use of the newly built stage 1 junior school buildings - which include four classrooms and a separate learning space - has been delayed.

A stipulation in the school's original development application requires that some shade cloths be installed before the classrooms can be put to use.

Consequently, for their first day of school, junior school students were placed into makeshift classrooms in the library and shared senior school spaces.

"There's no problem with the buildings at all, we're just waiting for the finalisation of a shade sail, that's it," Mr Humble said.

"We'll be in where we need to be next week."

Students in stages 2 and 3 will continue to occupy the existing buildings across the school's 33-acre footprint. Now beginning construction, the rest of the junior school is expected to be completed throughout 2021.

"I don't consider it to be an issue, it's just a little bit of re-rooting, [but] we're always hopeful everything would be ready to roll. It will just take a day or so more than we would hope for."

When fully constructed, the junior school will be able to accommodate 250 students.

This year, the senior school is also welcoming a large intake of 730 students from years 7 to 12. There will be 110 students doing their HSC this year, and the first intake of 18 International Baccalaureate students will also finish this year.

Additionally, making the leap from primary to high school will be 140 year 7 students.

"Every year that goes through, it gets largest," Mr Humble said.

"We have our largest intake of year 7 ever coming in this year."

Over the next 18 months, the college will also go through the process of becoming the region's first certified International Baccalaureate Primary Years Program school.

Until the school has secured approval to use the new rooms, Mr Humble said, there has had to be some strategic changes to senior and junior school class schedules to accommodate the needs of both.

"The joy of being a K to 12 school is that we've got space to be able to utilise, so they're in current classrooms," Mr Humble said.

"We have a lot of really good people that work out the timetables, so we prepared for all eventualities."

Despite the rain on Thursday morning, Mr Humble said he was pleased to see how many families arrived to drop-off multiple students in different year groups.

"About a third will be current families, which is great. That's one of the benefits of being a kindy through to 12 school, you can have the whole family in the one place," Mr Humble said.

"Seeing the drop-off [on Thursday] with kids in year 2, year 6, year 8, [from one family], it's just lovely. It's a really nice feel and that's part of what we're trying to develop here."