Did you know that expanding and adding more neighborhoods to existing worlds is possible?

I would love to have more lots but I wonder if people with low-end computers would be able to run the game even on low settings. I always remember a friend of mine who had a low-end computer that could just run TS2 but if we ever tried to place a new lot to the world, the game would crash every single time.
I wonder if that could be another reason why, who knows lol. Wish I could understand coding better!