I think it should be the same as your everyday carry.
Like anything else, the Home Defense gun is useless if its not available.
You have to have access yet only you should have access. It should be secure from kids and other non authorized people.
To do that it has to be on your person. Figuring it takes 3-5 seconds to kick in a locked door, we know its going to take longer then that to get from your couch or kitchen to the bedroom or closet and unlock your gun.
If its hidden where you can get to it, others can get to it,
UNLESS
Its concealed on your person. To do that it has to be comfortable, concealable, and accessible (not likely a child will be able to pick your pocket).
You're not going to conceal and carry a shotgun or rifle. You're not going to be able to comfortably conceal and carry a full size semi or revolver.
A small gun in your pocket beats a big gun in the truck or locked away by your bed or closet.
My first concern is no kids or grandkids have access to my guns, my second is that I do. Best way to accomplish this is to lock up all my guns in my safes, except the one that's on my person, only under my control, 24/7.