Can you build a two story house on Sims 2 for GameCube?

No you can not. No Sims games for Nintendo products have been made to build two-story houses. However, buy the Sims 2 Pets on PC and you CAN build them. Remember that you have to have a Sims @ or Sims @ Expanded Edition save on your computer before you can play the game. I went ahead and bought the game, now I can't play it nor can I return it until I buy the other games.