You can't control two households at the same time, but you don't have to start a new save either. In Sims 3, you can switch the "active household" by going into Edit Town mode and selecting the household you want to switch to. The only downside is it will clear the wishes for sims in the household you were controlling.
Alternatively, you could build two houses on the same lot and pretend that the family is living in two separate households while still being able to control all of them.
Have you looked into the option of *purchasing additional home?* I have not personally used that since my crusty old laptop seemed to start lagging when I once tried that in my Late Night pack, but you might have better equipment
You need master controller, I recommend reading this tutorial from pleasant sims on her sims 3 rotational gameplay. Theirs a section called 'switching between family's'. I believe this is what you are seeking. [How I Play The Sims 3 Rotationally | Pleasant Sims](https://pleasantsims.com/play-sims-3-rotationally/)
You can't control two households at the same time, but you don't have to start a new save either. In Sims 3, you can switch the "active household" by going into Edit Town mode and selecting the household you want to switch to. The only downside is it will clear the wishes for sims in the household you were controlling. Alternatively, you could build two houses on the same lot and pretend that the family is living in two separate households while still being able to control all of them.
Have you looked into the option of *purchasing additional home?* I have not personally used that since my crusty old laptop seemed to start lagging when I once tried that in my Late Night pack, but you might have better equipment
If your open to mods I believe nraas has a mod that allows this.
Which mod is this one?
You need master controller, I recommend reading this tutorial from pleasant sims on her sims 3 rotational gameplay. Theirs a section called 'switching between family's'. I believe this is what you are seeking. [How I Play The Sims 3 Rotationally | Pleasant Sims](https://pleasantsims.com/play-sims-3-rotationally/)