I sympathise with your mom's headache, but suay suay he had to
drill today.
If the timing allowed for noise is raised to 11:30pm, then you will
bear with the noise?
Likewise, you don't have enough money to buy private property, else
you will not have to take banging and clanging from
neighbours.
I say live and let live, it's not everyday they do this, sometimes
it's something pressing they have to settle.
I think common courtesy is needed, even if you confront him, do
tell your neighbour in a polite manner, I won't bump into him in
the lift, but chances of you bumping into him is very high and it's
not very plesant to meet someone whom you have mutual bad
feelings.