This is a very simple question. I am LOUD! 
Even with the new studio I am constantly aware of the ridiculous decibels I emit. When we began to move into the building I warned the landlord (his office backs up to mine) to periodically expect insane levels of sound. He took it like a champ! While I am working to improve the acoustics of the room I now would love to find a way to improve his situation as well. He hasn't put up a fuss but I would like to build relationships that last for a long time - not have a lease with someone why "tolerates" my favorite (income producing) pastime. 

This is not a new scenario. The last condo we lived in must have driven the neighbors insane! 4 hours of broken thirds and fingered octaves? That could drive anyone to the brink of insanity. Lets face it people, practice shouldn't sound good. Practice is the music equivalent of working out in the gym - your hair looks bad, you smell terrible and you make funny noises. Yet, we do it for the results all the working out (practicing) produces.

So fear not about the noise, try to be courteous whenever possible and become the artist you know is hiding under hours and hours of practice.