How to make more sims without building a new house

Answer from: Answerer
You must get a man & a woman to be partners (I'm not sure if it works with lesbians or gays). When you use the guy in conversation, you'll see a choice that says "Ask to move in", or something like that. Click on it. The girl will most likely accept. After she moves in, sell all of her house, move her pet, & sell the stuff you don't want. You will make some money from this.

Answer from: The kid
You could also make two sims "good friends" and then the option to move in together is also available then. Just have the sim living in the share house ask the other sim to move in with them.

Answer from: Soccer3
You have to make to sims be good friends or partners. Then you have them move in together and one of the sims houses is empty. You can click on it and click add a new sim.r

Answer from: dani
Yes, but why when you move them in together, the option to add a new sim to the now empty house is so expensive? They want 40k for me to add a sim

Answer from: nica
You could just remove the old house and build a new one(preferably the unfurnished one). That way you will have a new house and a new sim. :) Regarding the original question, you can make more sims by simply buying a cradle and creating a baby from there(btw, you'll need a married couple to do this). A baby costs about 3 LP I think.