Thanks to Nisrine El Ahmadi,(Belgium) for the idea of this challenge.
Make a stairway, with stairfoot and stairhead 1 and a landing, using a full set of pentominoes (see picture).
Make the stairway in such a way that the area is maximized.
The pentominoes have to be in one plane, and touch by a full sidelength of a unitsquare (point or corner connection isn’t enough).
Look at the example below to have a better understanding of the challenge.