...you're in your house, and therefore you want to have your self-defense ducks in a row. Whether you're in the shower or the kitchen or in your office concentrating on what you're reading on TFL, you want the same thing: easily-accessible self defense.
So have your alarm on when you are inside your house (I love that new Brinks commercial about alarm systems, guy goes off to work, wife goes in, shuts door and turns ON the alarm, and the BG who was watching the guy leave kicks in the front door only to hear the whoop, whoop, whoop of the alarm...). Get a dog if you don't have one. Even a chihuahua can be loud enough, although I'd suggest something a little larger
. Don't leave your windows unlocked. And leave your gun within reasonable reach.
Pretty much the same self defense strategy as any time you're in your house.