I can clear a room easy. Give me a can of pork and beans and in less than five minutes... CLEAR!!!
Just kidding. I cleared the house the other day. The alarm panel had some weird error message so I did it just to be safe. It is different when it is a property you are familiar with. You know the full layout of the house including the furniture (either potential hiding places for the bad guy or cover for you). It was at night so I grabbed a 3-Cell Maglight and went room to room. It might even help if you use your blueprints to make a house clearing plan (just in case).
I stay further away from the doorway and sweep my light in an arc. Just remember that most interior walls don't offer squat when it comes to protection. If you hug the doorway, the bad guy can shoot your unexposed parts through the wall. Don't laugh but I kind of point the gun "gangster" style (up high pointing downwards) I feel there is less of a chance for a gun grab since you aren't sticking your arms out as far into the uncleared room. I also feel it is safer than keeping it close to my body in case the bad guy takes a shot at the gun.
One other thing to consider is letting your dog do the searching for you if you normally keep it outside. Their noses should be able to lead you right to a bad guy if he is hiding in your house. My dog would probably eat the bad guy and I wouldn't have to lift a finger. I love my dog but I'd rather she take a bullet and flush out the bad guy instead of me getting shot. If I'm out of commision, I can't protect anyone else in the house!