The fire in Loreto on the Green was back in the 80s, early 90s at the latest. Very popular school though, I asked about dd for secondary when she was 3 and the waiting list was already closed for her intake of 12 year olds.
I have heard good and bad things about every school over the years.
DD goes to Rathdown as a catholic and there are many catholics there. The Protestant ethos is not a particularly religious one, but a sense of learning to be nice girls and participating in society and helping others. They have Service three times a year (start of the year, christmas, end of year) in the church a short walk away. But they also do things like each class makes a harvest basket just before midterm (filled with donations to the local foodbank but great bonding and creative activity for the classes and school). They have a House system, where merits for helping others, really good effort in class and results at annual sports day are added for the annual House Cup between the 4 Houses representing the original founding schools that merged many years ago. Facilities are pretty good, including a decent library accessible to all students (not necessarily the norm in Irish schools).
The general ethos is an expectation that the girls will all do their best academically, they are taught about study skills in 1st year and encouraged to do afternoon and/or evening study in school, even as day pupils, early on. So once those expectations are laid out, they focus on other soft skills and extra curriculars, as they are all working on their subjects as a matter of course. There are great extra curriculars that all are encouraged to join - loads of sport, Lego club (building and programming robots), debate, choir, model UN, book club, lots of music and art, the girls themselves run SUCH (the school's charity that raises money for a chosen charity every year through a show involving the whole school and various other events), etc.
There is a wide range of subjects, a few do extra subjects (e.g. a group of my DDs year wanted Italian as an extra language, so a teacher was brought in for a couple of afternoons to do that with those interested).
5th and 6th year boarders are in senior house, which are single rooms like Uni halls, with bed and study desk. They can either study there, or in the Prep hall with the other boarders, (all juniors do communal study, they share mostly 4 to a bedroom in junior boarding house), although any seniors who don't seem to put the effort in alone in their rooms are brought back to the Hall. Evening study for day pupils is in a different hall, but there is still interaction at the break mid-evening.
The cycle is roughly 3 weeks at school, and the 3rd weekend boarders are expected to leave, as well as midterms and holidays. Some leave every weekend (relatively local in Ireland), but there are a number of international students and other Irish who stay in many/all weekends. There are fun activities and outings for boarders at weekends, and they are allowed visit friends locally as well with permission.
Sorry, that was longer than I intended but mainly meant to show that the non-catholic thing is not a rampant indoctrination into Church of Ireland, more a sense of caring for the well-being and rounded growth of the whole person for each student. Despite being a very strong academic school with very good results annually.
In many schools, (I.e. not just Rathdown), there is a study hall where any students not having a timetabled class will go for supervision, to do homework and study in that period. Generally 5th and 6th years have 1 class cycle that they don't have a class per week (2 singles and a double) as many will do 7 but the timetable covers 8 to fit everything and the choices into the week. But this also means that those with an Irish exception have somewhere to go for those periods (4 or 5 singles a week). Or there may be an option, depending on the school, to have another class instead.