I think even the old bricks are not so old, it's a small village, I guess till 40-50 years ago, they were using stones to build walls. (like part of what you see in the right wall).

Next time I will examine it, I think the wall on the back is completely different from the right wall (even the lower part of it).

The wooden door in the back is about half a meter in the ground, so looks like you're right, the ground was about half meter lower before, and probably there was a wall a bit more than half meter, just to separate the lands, then the wanted to build a house and made a new wall on that old one.

But again you don't see really old brick walls in that village, it's either stone walls or mud (?) walls.