Your house probably got struck by lightning.
Even though it is unlikely, it seems to be the only possible theory left, and makes perfect sense. The house probably started burning from the inside after the lightning struck, and as soon as the roof caught fire and got destroyed, the fire on the walls and floor got extinguished by the rain from the thunderstorm that caused the lightning in the first place.
This explains why only wood got destroyed without glass, chests and the door getting destroyed. The pattern of destroyed blocks could also possibly be created by the fire, since there are remaining blocks scattered around, which is typical of fire to do.
Edit:
As sandman9601 said in [his well-explained answer][1], the missing blocks can be a result of a bug or error, since the dirt that was below the wood planks didn't turn into grass. However, this does not mean that my theory is invalid. Grass does not spread/grow during the night or thunderstorms, which is why it didn't cover much ground.sandman's theory is not impossible, but still less likely than lightning striking.