I have a good relationship with my neighbors. If you are good with your neighbors, they put up with a whole lot as long as you don't push it. I always keep my forging limited to Saturdays most of the time, and even then just daytime. Saturdays are the traditional days here in Belgium when people mow their lawn, cut trees, use angle grinders outside etc.
Even with a power hammer, there is only so much forging you can do in a sensible manner because you still need to do all the time consuming grinding, polishing, scales, etc..