Iron / Steel Building Material Type
With the addition of deep drilling for iron, there can easily be a surplus on long missions (and hopefully outposts). It would be nice to reskin the aluminum as another type such as steel or iron, with greater durability vs. storms than aluminum. Perhaps keep the roof style of concrete (and redo the ramps/roof of concrete to actually look like concrete).
Somewhat related; it will also be nice if all building materials had comparable piece behavior in terms of rotation/orientation, double-doorways, double-windows, etc. I know I may need to find a suggestion specific to that of course.