homes in the 80s when I was a kid. It's not really a new concept. As my parents' family grew, they had no choice but to look into bigger homes in the area, so they did. But couldn't find one they liked better. So they did a major add-on and remodel to fit the family.

Young and small families start smaller, then when they need more room and a place teenagers are comfortable hanging out they look for something bigger. Feels pretty natural to me.