i like the way the first screenshot is going, the others still look a little bland to me.
the plain metal walls and the snow don´t melt well together as it is, like two seperate entities that dont belong together
give it some subtle supportstructure, concrete footing, some framing
second thing, i know you probably won´t see it ingame that good, but having thick snow lying on the ground and none on the roofs leaves me with an unfinished feeling....
i know, i know, early stage
just mentioning