Don't forget that even doing the multi generation home means that there is little space for human expansion there. So while I grew up with my great grandparents the room they used up is now my siblings. Even in my cousins house they only got their own room because their great grandma died and grandfather died. Then my other cousin took over the 2 car garage and turned it into a living suite. And the Basement? Last cousin took it over. These are just adults that cant do any better. How are they going to find room for kids unless someone else dies?