Abstract: A drainage system for draining water away from a building having a horizontal base and walls extending vertically from the base. The drainage system includes first drain means located in a first trench provided in the ground beneath the base inside the perimeter thereof. The first trench extends around the perimeter of the base and inside of the vertically extending walls. Second drain means is located in a second trench provided in the ground adjacent the ground surface and adjacent the perimeter of the horizontal base. The second trench extends around the perimeter of the horizontal base and outside of the vertically extending walls. A gravel filling is provided in the first and second trenches and covers at least partially the first and second drain tiles.