2 months ago there was a story about a huge family mansion in Meath being demolished after a court found they did not have the proper planning permissions, and the council was unwilling to grant the permissions after the fact. Also just last week a judge ordered the demolition/removal of 26 mobile homes from a site in Dublin set up without permissions.

Friends of mine recently got planning permission for a house they've been living in for about 3 years already.

So you can def roll the dice on such things, maybe you get away with it for decades, maybe your house gets flattened.

My (also an immigrant like you) take on Ireland is that many of these systems are run and controlled by humans, and you can get pretty far by trying to make that human connection with the people controlling your fate. My wife was initially refused maternity benefit, because she did not have enough social security contributions. She works part-time, and she was missing 1 contribution (about €120) out of something like 38 for the year. After friends (the same from above) suggested we phone them and talk to the people, the maternity benefit application was approved. I find that there is a lot less "sorry can't help you, computer says no" here.