One thing worth noting is the soil, if memory serves, the moon soil hs been described as being very sharp and clingy with some properties of asbestos, as in its very problematic. This is because there has been no water, winds etc to grind the sand as on earth.

Now on Mars the soil has been moved by winds and other natural phenomenon, so it should be far less problematic to just brush it off, not to begin on the more useful composition of it, I can imagine the iron will come in handy when the habitat gets to the point where they can start refining and producing.