5 floors :P My god, that's a huge house. :P

the ground floor is included

I would say 5 and I would call it a building.

http://en.wikipedia.org/wiki/Storey here is the link...

I was wrong. Below is the answer to your question There are two major schemes in use across the world. In one system, used for instance in the British Isles, the floor just above the ground floor is assigned the number 1 (or "first"); in the other system, used in the United States, that same floor is number 2 (or "second"). In both systems, the numbering of higher floors continues sequentially as one goes up, as shown in the following table: Displacement from ground level British convention American convention 3 story heights above ground "3rd floor" "4th floor" 2 story heights above ground "2nd floor" "3rd floor" 1 story height above ground "1st floor" "2nd floor" at ground level "Ground floor" "Ground floor" or "1st floor"