We've always been the sort to knock on neighbours doors to say 'hello' when we've moved in, and always let them know if we're having work done that might cause them noise/dust.
Anyway, we have new neighbours. Hadn't seen them, so knocked on door and said a quick 'hello, welcome and if ever want to check anything'. One of them was in, but the other hasn't come around to say 'hello' and a few of the neighbours are surprised they haven't spoken to anyone (large cul-de-sac).
So we have two things coming up now that will affect them. Ongoing problems with our roof, roofer is coming back tomorrow to replace membrane on our side near (but not on) the party wall. He is removing our flashing which overlaps theirs and replacing. Then next week, we're having a new bathroom the other side of their bedroom, so they'll be noise from that. If the fitter cuts tiles outside, he'll be doing it on the other side so it won't affect them with dust/noise.
Would you let them know? She wasn't in when I got back from work and DH said not to bother.