or so, and the pattern of your shotgun is but 1" wide per yard of forward travel from the muzzle (unchoked barrel and 00 buckshot). Most attacks are not made with a gun, check out the Dept of Justice website for the Annual Crime Survey. So it makes far more sense to ccw a pistol around your house than to count upon being able to run and get any sort of longarm.
you also want a AA cell flashlight, preferably also always carried with you, at least when it's dark, with a side button, not the silly, expensive ones with the button on the butt of the light. Then, your weak hand's thumb can encircle the light, holding the light and gun in a normal 2 handed firing position, not some hokey, bass ackwards version of a grip! The side button lets you turn the light off and on.
Me, in my house, I'm TURNING ON THE LIGHTS if I think there's an invader. I'm not wanderiing around in the dark, showing a light, letting him see and hear me coming, and letting him "jump" me, throw a crowbar at me from the dark, etc. The flashlight is just for checking unlighted sheds, the yard, etc, and you really SHOULD have a dog and lights back there, anyway. Few burlgars, etc, carry guns, or can hit jack squat with one if they do have it. Pointing a gun-light and the gun, too, at people is a bad idea. I want the light held separetely from the gun. That "invader" is probably your kid, come in late, etc. Don't risk suffering the horror of shooting a loved one, guys.
It doesn't need to be a big, mean dog, just one that barks at strangers. Big dogs are too likely to get you sued for tearing up some little kid that lets him out, and they cost a lot to feed, too.
A fast man, starting from a standing position, can cover 10 ft in 1.0 second, 20 ft in 1.5 seconds, 30 ft in 2.5 seconds, having built up some speed as he came, you see. Drop a coin from as high as you can hold it, it will hit the floor in 1.0 second. Drop it from waist height, it hits the floor in 1/2 second. You can and should learn to get 5-6 hits per second with a good handgun, guys. Don't hesitate, don't turn your back, and be sure to wear ear protection and use cover whenever possible.
A powerful gun, used indoors, is horrifically loud. In fact, the flash and blast of a 12 ga load is so bad that it can nearly make you drop the gun! I kid you not! The difference between magnum buckshot and a trap load is tremendous, when fired indoors, don't kid yourself about this. If you can go get a gun, you have time to put on a set of electronic muffs, too, and turn them on, or insert a $30 set of Norton "earvalve" ear plugs. Then you can hear normal sounds, but your ears will be protected by the blast. the flashes, at night, indoors, will steal your (night-adapted) vision, rendering you blind in the dark, if you don't have a light. Bird shot pellets often bounce back from even telephone poles. I had a bunch of such pellets almost imbed themselves in my shins after such a shot. So they can strike your face after hitting, say, the refrigerator! There's a LOT more to having the odds heavily in your favor in a defensive situation than simply picking up a 12 ga.