Solid 3.5ominoes with Holes

Take the two solid trominoes with unit height and add a unit cube at their vertical faces. If this cube can be diagonally sliced with one cut you get 20 different pieces, which can be used to construct flat and 3-dimensional figures. Since faces with a 45 degree slope can't be put on each other, little holes on these faces are provided, which can be connected by little boxes preventing the pieces to slide down.