@4812Tthe 'care for self' function appears if you are playing with a sim on one lot but you have multiple sims in your household who are not on that lot. You can select a number of options for the other sims in your household by clicking on the little icon which appears on their little sim picture on the bottom of the screen. A number of options appear include "care for self" (i.e. take care of needs), "bring here", "switch to this sim", "build skill" (if i recall correctly). It is a temporary feature which ends when all your sims are on the same lot.
For example, you are playing with a household of 2 sims. You leave Sim-1 at home and take Sim-2 to the gym and play at the gym lot. Sim-1 will be slightly greyed out and you have the option to set 'what they do while you are not there', including the option to "care for self". When you are finished playing at the gym lot with Sim-2 and you return to your home lot, the 'care for self' function will disappear as both sims will now be on the same home lot.
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Alternatively, do you mean the 'autonomy' function? Accessed via Game Options -> Gameplay -> Autonomy. There are three options:
Full: autonomy is on for all sims, meaning that all sims in your household will automatically 'do stuff' which fulfils their needs/wants
Disable for selected sim: autonomy is OFF for the selected sim, but ON for everyone else in the household, meaning that the Sim you have selected will NOT do anything of their own accord, but all other sims in the household will
Off: autonomy is off for all sims in the household, meaning that all sims will NOT automatically 'do stuff' which fulfils their needs/wants
Edit: detail
@Thats_Me_Madz@4812T
Good answer! The only thing I'll add to that is the reason the house got unfurnished is because when you moved the sim out, you opted to take all the furnishings with you. If you do that, there will be nothing left in the home.
In order to leave it furnished, you have to choose to not take them with you. But if you do that, you might leave some personal things behind.
What I usually do, is before moving out, I take any personal stuff I want them to keep, like paintings, purchased items I want them to take with them that didn't come on the original lot like exercise equipment, post cards, decorations and such, put it all in the household inventory and sell everything else. The household inventory is taken with them.
If the house is already unfurnished, there might be something you can do. If it's a vanilla lot, one that was already there when you hit "New" game, you can start another new game, edit the lot in build mode and upload it to your library. Then, exit and load up your other save where its empty and place the lot back from your library.
If it was one you created, you can place it from your library if you managed to save a copy while it was furnished, but if you didn't, then you'll just have to furnish it again. Remember to save a copy though to your library. I always save copies of all my custom lots to the library JIC.
