I'm doing this challenge where I'm playing a male trying to impregnate as many women as possible. But a majority of them always have this '' this sim's household is full so she can't get pregnant '' note whenver I try to click on Try For Baby. How do I fix that? Because I'm not even sure that a lot of them even have houses, I'm wondering if the game/nraas mods has merged all homeless sims into one household.

How do I fix this?

What?! I could've swore on that I have been able to before, oh well. Any way to fix this?!

The Nraas Wiki has several mods that can allow more than 8 sims in a household. What I linked should give you some ideas on which mods to obtain.

Even with NRaas mods, you cannot impregnate a homeless sim. While the homeless "household" limit is a factor, so that message is not totally incorrect, the homeless household also cannot accommodate babies or toddlers. But what you can do is make some of these homeless sims residents first by moving them into their own house(s). Note that Service Sims will instantly lose their Service assignments that way. Role Sims will be okay if you have Register and allow residents to fulfill Role assignments, as long as you never make them the active household.

Homeless sims who are performing regular Rabbit Hole and probably Showtime type job functions should be fine if brought in as residents.

Doesn't Nraas move homeless sims into homes? I mean, other than the option to run them out of town in the first place.

It depends on what kind of homeless sims we are talking about.

There is a setting in StoryProgression that is supposed to coax the homeless who are not Role/Service Sims into moving into homes and becoming residents. Frankly, I've never had any luck with that (probably a malfunction with the Home Inspection function) and use MasterController's Add Sim to make that happen on command when I want to instead. The alternative to running them out of town is to just leave them be. They are volatile though, and often wander out of the game individually on their own, usually when the player least wants them to and as co-workers most often if you switch active households.

But those in the NPC/Service "household" are also left alone. Guess I shouldn't be calling them homeless as that's confusing, but was concerned that the OP was trying to impregnate the maid or a cash register attendant and that won't work (unless the register attendant is also a resident).

no it does not. Some of the service sims *pretend* they lives in apartaments, but they of course doesn't, they just hibernate like anyone unused service sim. Only *residents* actualy lives in town, the rest is just an illusion called when needed for a specific task.

[EDIT]
according to above: settling homeless with SP never worked for me either, anyway - there's not really a point for settling them down because no resident can get "service" job - except consigment clerk and probably other register-type jobs. No way your kid or other resident kid would work as paperboy/girl for example. So - when they would be crashed in some house, the game generate another homeles' to take the job actually abandoned.
[/EDIT]

Right, but there are also homeless sims that the game generates to provide Rabbit Hole co-workers and bosses for others when it thinks there aren't enough residents in town to take those slots. Sometimes I've seen entire homeless families spawn that way, just with no one younger than a child.

Those are the ones I believe the SP setting is supposed to help guide into houses and become residents. But it tends to not work well, and you do have to have "Manage the Homeless" on to get that option -- which means they are all also subject to cleanup and being run out of town if the housing thing isn't successful or the player doesn't step in quickly enough to help them out.

I just find it easier to manage them all myself. There aren't that many homeless non-Service/Role sims in any given world anyway, or at least there shouldn't be.