The plot is 13.5 width by 25 length.
the hard structure building should consist of 4 houses. two at ground floor and two at first floor. the wall thickness should be 25 cm (bricks & cement).
Each house consist of (living room, kitchen, one bathroom, three bed rooms & small storing area)
The two first floors are completely isolated from the ground floor houses (one external stair for both 1st floor houses).