The tricky part with "no permit needed" is that while you can just go and do whatever, if someone charged with enforcement suspects you're doing something that requires a permit, they can still demand you prove you don't (and stop work until you do), and if you guessed wrong and you did indeed need a permit, you're double-fucked.
That's why for many of these processes, there's also something like a certificate of no-permit needed, where you go through an abbreviated permitting process spending a lot of time and money while all of the clerks and officials stare at you like you're a moron before finally giving you a piece of paper saying you didn't need to do any of that in the first place.
And that's why a lot of people with a lot of experience and a good understanding of the law skip getting a "no permit needed" certificate.
I am assuming it's similar in other countries.