From marketwatch.com:

These aren’t just friends turned roommates. Couples, multigenerational families and people with no relationship to each other are joining the growing ranks of those who are in “doubled-up” households.

Technically, these are households with at least one additional adult who is not in school, and not the householder’s spouse or partner. This year about 30% of adults, 69.2 million people, are living in doubled-up households, compared with 27.7%, or 61.7 million, in 2007, according to a September report on income, poverty and health insurance from the Census Bureau. 

In spring 2011, there were 21.8 million doubled-up households, or 18.3% of all households, up from 19.7 million, or 17%, in spring 2007.

While the benefits of house-sharing are clear — splitting expenses and pooling resources — running such a household can be tricky. Even within a single-family household, the daily morning chaos of getting everyone out the door on time, clean and happy, is no low bar. Now double that.

Read the full article here:

http://www.marketwatch.com/story/more-adults-in-doubled-up-households-2011-11-22