I installed a homeworld university in my current save, which seems to be functioning fine, however, I've noticed inactive families are getting roommates that aren't even from the NPC or homeless pool. They are literally being created to fill the house (one is a single dad with 3 toddlers) even if the house is nearly full to begin with. Is this happening because my game thinks it's now a university world and it's filling up the households (i.e. do I just need to try fixing the households) or is there a larger fix I need to do for this to make it stick? There are at least 3 households that have taken on roommates. I've set the whole town to not be rentable in SP, but perhaps I've missed one refering to roommates.

Not rentable isn't a bad idea for those who do not want to have the landlord/tenant feature engaged, but that's not the same thing as Roommates. Roommates are NPCs. Tenants are resident households who either cannot or do not wish to purchase their own houses and prefer to rent instead (thus building up no real estate equity but making life along the way perhaps more affordable), or those who annoyingly have their own homes purchased out from under them and become tenants, while hopefully getting credited with the real estate sale.

Anyway, I have no experience with Homeworld Universities so I'm admittedly not the best person to be answering. But I guess I would want to know if the lots these households live on have somehow become Apartments as can be seen when the lot type is viewed in Edit Town or if instead somehow the town's Roommate Service got engaged on them.

Thank you for the explanation between which sims were NPCs and which sims were just in need of housing! I had never seen these sims before, but looked in one of my sims relationships and it showed that she knew them.

I went through and changed households to the homes where this is happening. First, I checked to make sure the room mate system had not been enabled and it has not. Also, in edit town, the house (as well as all others), still look and appear to be a normal home and only give me the normal options (split, evict, etc.).

The sims that were added seem to have been sims that went to HS and elementary school with one of my active sims, along with a sim created to be their father. Oddly, after I started the game up, the toddlers I spoke of before, were deleted from the game by either overwatch or errortrap (along with a boatload of other sims). I don't know why the game decided to move in these old "co-workers" to an already existing home. There are plenty of children at the HS and elementary school and none of my active household is currently going to those schools. I have allowed for homeless sims with SP, so I don't know why these sims didn't stay that way.

I did pull some recently added mods from my mods folder, although I cannot see how they could have been the culprit (a lighting mod, zerubu's UC, no crappy bunk beds, no bad photos, unlock simport rewards). I also added some households to my library (everyone from Nraas) from my old mac since I can hardly get it to stay on and am afraid it may be on it's last leg, so I'm getting all the files I can off of it.

I haven't let the game run since pulling these mods, so I will probably let it run for a bit and see if it helps. I may just do a TA on those offending sims and see if the game moves in any other homeless sims.

On a small side note, is there a way to set in SP how large a litter of kittens and puppies can be at the largest? I don't recall households ever having 3 pets at a time and the routing issues are a bit of a nightmare in these homes.

Is SP > General Options > Options: Households > Manage the Homeless set to True or False? Is the story progression checkbox in the built-in Game Options set to off (unchecked) so that EA's version of story progression should never take hold in the event there is a delay in NRaas SP kicking in at the game's startup?

My reason for asking is that with Manage the Homeless on False and the checkbox not selected in Game Options (which shouldn't in an otherwise perfect world make any difference anyway as long as SP's progression remains enabled at all times), I have never seen the game shove homeless sims into existing households as described and as other players have sometimes found happening. The only exception is if a homeless sim sires (fathers) a child, they should be forced to move into town one way or another so that their genetics can be used when the baby is born.

But regardless, it does sound like something just kind of hiccuped here.

I don't know how to control litter sizes, but SP's default value for Maximum Size:Pet per household is 6. Maybe reducing that per household or across the board would cut down on the litter overflow?