Starfield's outpost system is an evolution of the base-building feature that debuted in Fallout 4, but despite some neat features, it ended up feeling like a regression for many players. You can't build an outpost on a space station (without mods, at least), and the game seems more focused on features like shipbuilding instead.

The great news is that modders are continually improving the feature, and the new B.A.S.E. mod created by LixZg created an experience much closer to that seen in Fallout 4, including the ability to build actual buildings, complete with windows, stairs, and multiple floors.

It fits naturally into the flow of the existing building tools, and works very similar to Fallout 4 - you can place a concrete foundation in order to make a flat area to build upon - with the ability to place doorways, multiple walls, floor and ceiling types, and even stairs and windows.

You can then place the existing furniture from Starfield inside your buildings, and it should all come together nicely. Several other mods enhance the base building system but note these might cause a few glitches or bugs.

LixZg promises more features are coming, including more staircase variations, shapes and pieces, and even catwalks. You can download the mod here.