There can be a number of reasons for the compass changing like that: magnetic, electrical, or metal interference being the most likely.
If you are measuring from the center of the house or room and the directions skew like that depending on where you are in the room, go with the directions you know that are so.
If you move around a room and no matter where you are in the room, the compass is always off in the same way, go with that since the room's energy is consistently skewed in the same way.
If you are standing in the front door facing out and your compass skews its directions as you move it 5" this way or that, stick with the reading you get from standing on the threshold in the center of that entrance.
Much Love, Shawn