Yeah, there has been a lot of talk about this. I think there was a reference from one of the staff or heavy modders that rooms should be at least 6x8? I’ll see if I can find that, but in the meanwhile here are a couple links of relevance:
You (and several others) have talked about ideas like giving “morale points” (or some such) to furniture, windows, lighting, that sort of thing. It sounds like a good idea. It might - especially for multi-room dwellings - require that the longstanding “free-standing walls break roofs” bug actually get fixed if you define a dwelling as a roofed space but otherwise, the idea of having nice things leading to people feeling happier? That makes sense. Start with an open barracks - meh. A Hearthling can live in those. But eventually getting individual homes (especially if the “personal space” markers that have been described as suggestions get implemented) with fine quality, comfy beds, a couple chairs, a writing desk and table? Yeah, a Hearthling can live in there with style