I'm sure you ran across this: http://lilsimsie.tumblr.com/post/157671494755/not-so-berry-legacy-challenge
and there is a thread here that is active about the challenge https://forums.thesims.com/en_US/discussion/914114/not-so-berry-legacy-challenge/p22 that I'm sure would welcome and give advise or recommendations to you.
Hopefully, they or others here can direct you better but it looks like every generation has a color and things they have to accomplish. So your house could reflect that color and have space for things they need to do in that generation or even some of the items included. You could always also look on the gallery at builds made and get more insight that way also.