A house is a sterile object built for shelter. A home is a house with emotional attachment.
You can beautify your house and it would be your home. A home is usually full of charm and memories.
You walk around your house to look for your keys. You sit on a couch at home and watch TV.
If you're not doing anything particular that day, and you were bored or tired of sitting, you might just walk around the house to stretch or get some fresh air (back porch). That's a mechanical activity, so you should use "house."
Once you sit down again, you're at home, watching TV. That's a comfortable activity, so you should use "home".
Home is a place of comfort in your mind. "Home Sweet Home"
--lotus