The number of children attending primary schools is expected to fall by almost a quarter over the next 17 years, with the decline most acute in Dublin at 28%, according to Department of Education projections.
Enrolment estimates which were published today see post-primary school enrolment continuing to grow strongly for the next five years before those numbers too begin to reduce.
In all there will be an 11% increase in the number of students in post-primary schooling by 2024.
The estimates are based on Central Statistics Office projections, as well as assumptions regarding migration, the birth rate and other factors.
Between 2000 and 2018 the primary school system experienced dramatic expansion with an almost 30%, or 126,000, increase in pupil numbers.
This new analysis now forecasts a fall of 134,000 by 2036, with this averaging out at around 10,650 fewer pupils annually between 2021 and 2028.
It estimates that after 2036 primary school enrolment will begin to grow again.
The report finds that the fall in enrolments will not be evenly distributed.
It predicts that enrolments in primary schools in Dublin will fall by 28%, while in the mid-east region, which includes the Dublin commuter counties, and the midlands, enrolments will fall by just over 12%.
These regional enrolment projections are based on a modelling scenario which assumes demographic movement out of the city and into suburban and commuter belt areas.
When it comes to increased enrolment at post primary level, this too is predicted to be geographically uneven.
Post-primary numbers in Dublin are expected to increase by 15% by 2024.
The increase will be slighter in other parts of the country: by almost 6% in the west and by just over 6% in the southeast.
This data will be used by the Department of Education in planning new schools and school buildings for coming years.
Commenting on the report, Minister for Education Joe McHugh said the projection was "a hugely important piece of work, especially in the context of the massive investment in school building projects under Project Ireland 2040".
He said the report would "play an important role in future planning at a regional level for our primary and post-primary schools over the coming years".
