It is difficult to make precise comparisons between the levels of grants paid and the actual costs of running schools at primary and post-primary levels. However it is self-evident that the maintenance and running costs for second level schools are much greater on a unit cost basis than those in primary schools.
In general, post-primary schools are larger than primary schools and have a lower pupil teacher ratio resulting in more classrooms and specialist rooms such as laboratories, workshops and kitchens. This leads to higher unit costs in second level schools for heat, light, power, maintenance and cleaning.