Now the oldest boomers are old enough to be thinking about retirement communities, many of them have the notion that those should be green, or environmentally sustainable.

There are some builders and developers who are free with the terms "green" or sustainable. But luckily there are several new standards that you can use to evaluate those green claims.

The permanent and semi-permanent RVers, many of whom have sold everything – homes, condos, cars, furniture and all – to live as turtles, as one friend described it, carrying their homes on their backs for as long as they enjoy it.