Same way I'd defend against any other threat in my house. Alarm goes off, call 911, hole up in my room looking towards the stairs (I sleep on the second story) Wait for cops to show up or badguys to come up the stairs. I have insurance on all the crap downstairs, if they steal my TV and bounce I could care less but you come up the stairs I'm going to stop you.
Glock 17 (Dad's old duty sidearm)
And some other stuff