I installed a wood burning stove last winter. I did it in a way that I doubt complies with code but I am pretty comfortable with. I put a layer of cement board down on the carpet it was fire rated dry wall as I recall. I then put one of the metal plates for the stove to rest on on top of the cement board. I then put a layer of red brick on top of that. The stove rests directly on top of these three layers. I did not have the space to put the legs under it so it rests on the bricks. I made sure there was at least 12 inches of clearance around the stove door before it reaches carpet. I took the stove pipe up and and vented it into the fireplace. I tapes a piece of sheet metal over the fireplace opening with metal duct tape, cut a six inch hole in it and put the stove pipe through it. The stove pipe empties directly under the chimney for the original fireplace.
I have been thinking about taking some of the bricks away so the center body of the stove is open to the air. I am thinking if I can get more airflow across the metal I will get more heat from it. My biggest concern with doing that is I lose the thermal mass of the bricks. Any thoughts are welcome.
I like the wood burning stove because it makes a huge difference in the comfort of my home. The fuel is renewable and mostly free. I live in Atlanta, GA and there is always someone saying "if you haul this tree away you can have it" so I have a chainsaw, an ax, a sledge hammer, a wedge, and a wood maul. It costs me a couple of hours to cut up enough wood for a week and the gas to go get it.
I think of this as being very efficient, for me.