Buildings can be adaptable in many ways. Some are obvious, like the large house that becomes an attorney's office a couple generations later. American houses once were home to many generations of the same family, but we've so custom-fit today's house designs around single market demographics that when you enter another stage of life, you have to find somewhere else to live. This house breaks that mold, and is able to welcome three generations or more of a family to live there at once. Here's how it works.