It is common sense for most of the population, that 3 in the morning is not the time to be starting your circular saw in the backyard. So why is that pesky neighbour insisting on doing just that? Well, unless someone asks that neighbour no one will ever know. So maybe the best approach would be to go and calmly talk to your next door neighbour and explain why you find their behavior disruptive and possibly work out a better way of doing things that might suit both of you. The neighbour may have a perfectly good explanation for what they are doing and it has not occurred to them that they were affecting anyone else.
If a rational discussion does not resolve your issues, than you have the option of recording the time and date of the occurrences of each offense and formally writing a letter to your neighbour listing each offense and detailing the course of your future actions if the situation does not resolve itself. The next step is up to the individual and how far they want to push a situation. One choice would be to find a mediator; the other choice would be to contact the local authorities.
A word of caution is in order here, the authorities will be more responsive if you have tried to do everything you could on your own before involving them and another point is whatever it is you decide to do, you are the one that has to live next to this neighbour for who knows how long. As long as you are comfortable with your decisions and not being deliberately cruel to anyone, it is entirely up to you how to handle that pesky, disruptive neighbour.
