I found out “the hard way” how to build them. As the mod author says, it’s unlocked by researching Steam Power, which gives access to a housing that produces them.
Now, regarding the “understanding flow,” there are issues. This isn’t mentioned in the initial documentation or on the mod’s front page (I don’t know why the mod author doesn’t just ask an AI to summarize their tips and place it there—oh well).
Then, when you start getting tips, the only one about civilians only appears when you research the steam engine! So the core concept of the mod—having civilians—is not explained for a long time. (I'm playing on ultra death world with Rampants, and steam tech only came after 6 hours of gameplay!)
You start with a depot, but you can’t do anything with it, and there’s nothing explaining what to do next.
The mod is probably awesome—it clearly shows a lot of effort went into it. I’m almost ready with my new base to finally plop down lots of houses and such. But the explanations are lacking, and it’s not because the mod is complex—it’s the information flow that’s off. As I said, at worst, just ask an AI to make a summary and put it somewhere.