Rags to riches

One of the R2R challenges requires you to build a home with a specific number of rooms, get married, raise a family, become a grandparent, etc, but you can just do it your way and complete the challenge with a single sim and a modest sized home.

Here's a guide to one of the original challenges that you can modify as you like.

https://snootysims.com/wiki/sims-4/rags-to-riches-challenge/