OK guys i have a few questions so please bare with me. I have university life installed and im currently playing in Sunset Valley, not the actual uni. So when I click edit town and click on an empty lot i see you can switch between residential or community lot. When you click on residential lot you can then pick either regular lot or apartment lot.

1. My first question is whats the difference between picking either? Ive asked NPCs to be roommates in both and have gotten issues with both. Notably when I evict my sims to switch the lot into an apartment residency it disables the roommate tab in my phone that allows me to turn off roommate service, set max....

2. I made an upstairs room where I was planning to add 3 roommates however those NPCS then continue to enter the downstairs home and use my stuff at will, change the channel when im watching tv, try to enter my locked bedrooms, eat my food despite the fact that i placed the necessary utilities in their own pad....fridge, bed, bathroom etc. They keep using my place.

Heres My apartment guys, this is the downstairs

and heres the upstairs.
I was hoping to keep three of them upstairs not lounging around my main place. Itd be fine if they visited me and asked to come inside but they dont have any common courtesy they just barge in to their landlords place whenever they feel like it! What am I doing wrong? What do I need to change to get them out into their own part of the lot?

3. Is there any particular reason why an npc will not have the option to 'ask to be roommate?' It worked for two of the three I wanted but not the third, I dont see it. I have checked to see they are single, young adult, and are at best friend status with the sim asking. The sim asking is also not a teenager, child etc if that counts. I have noticed the move in option has also disappeared, Is it a bug like the one I mentioned in my first question? Id hate to think this is by actual design....

For all three questions? How about a link, kind stranger?

bump the bump

Sorry, I'm feeling too lazy myself to hit the search button today.

A LN style Apartment is a Regular residential lot with a public area (room marker) and an NPC door. There is only one usable unit for resident sims, active or otherwise, to live in. Behind the NPC door, all is black and you can't get in there. This is where "homeless" NPC sims go to hibernate instead of disappearing off the map when off duty as they would if no such buildings were available in town to give the illusion that other families live in the building. You can summon the NPC neighbors using the call box, but it's still not really the case that other resident households live there. Usually we see LN style Apartments in highrise shells with the one usable unit on an upper floor reachable by elevator, but they don't have to be arranged that way.

A Uni style Apartment is an Apartment type lot. There is again only one household, but the sims who live there get NPC roommates and unless you deploy some form of door locking, they all share the same living space. You cannot switch off the Roommate Service on an Apartment type lot, which is why that option is greyed out on the phone. It's really the Uni dormitory concept that can be used, if desired, in other worlds apart from Uni World. I find these types of lots annoying to work with.

It sounds like what you want is one lot with multiple distinct residential households living in their own assigned portions of it. You can't really do that in TS3, although there are some mods that can help you get a little bit closer to something like it.
http://nraas.wikispaces.com/Apartment+Mod
http://modthesims.info/download.php?t=554197

I just want to add that since it's realize the LN hidden and public markers has been made basegame, so you don't need any exp for this to work anymore. I wonder though didn't it come with Ambitions? I may remember wrong. I know it was used in LN. It's a nice way to fill a house with people for sims to talk too, but having fully working families from the towns resident population living in the apartment building isn't possible.

Homeless/townie population fill certain roles in a town and doesn't really need anywhere to stay for a world builder.
NPC's fill the roles you call for on the phone and need somewhere to stay in a town.
It's very easy to mix them together, but they are different. When I made my world I had 200 characters and made them fill the different roles. I guess most world buildes will just make some resident sims and don't bother with the rest. The game will just make some pudding faces as it's needed.

You're probably right, in fact I assumed both types of apartments had been added in with patches for those who don't have the EPs (but that might not be the case with the Uni type). I just refer to them as LN "Style" since Bridgeport is the type of world so many of us associate those with the most. But I've seen some very clever deployments of those in buildings that are not highrises in worlds that do not have urban centers, so the markers being base game is totally reasonable.