The data suggests some Nevadans turned to family to survive a years-long economic downturn that has brought record foreclosures, joblessness and bankruptcies to a state once awash in job openings and newly built homes.
"There are people sleeping in every vacant room they can," said Mike Young, president of the Nevada Association of Realtors. "They are struggling, and it shows the breadth of the problems we have."
Nevadans weren't too picky about who they shacked up with last year. They also shared a roof with extended family members and nonrelatives, the figures released Wednesday show.
For example, in 2000, nearly 47,000 homeowners were living with relatives other than a spouse, child, sibling or parent. In 2010, that number grew to nearly 79,000, including more than 23,600 nieces, nephews, cousins or other relatives under 18. That's a 68 percent increase.
The number of unrelated housemates also increased, with more people living with roommates, unmarried partners and other nonrelatives. Still, only 16 percent of Nevadans lived with people they weren't related to last year.
Much older housemates were not uncommon. Grandchildren roomed with grandparents, with that population growing from nearly 35,000 in 2000 to 62,000 in 2010, a 77 percent hike. Adult children bunked with their elders, too, with the number of adult children living with their parents nearly doubling during that decade.
Meanwhile, more homeowners let their parents or siblings move in, according to the Census. In all, roughly 5.4 percent of Nevada homes consisted of family members from more than two generations.
Hispanics had the largest average family size, with 3.98 people, followed by Asians, blacks and then whites, with 3.02 people.
The changes partly reflect Nevada's record population boom during the last decade, when it grew by 35 percent, the largest percent in the nation. Census data does not detail cause and effect; it's merely a snapshot of a state at a given time.
But sociologists and housing experts said stories of one-roof families became more widespread after Nevada's robust job market started to shrink in 2008. The state's unemployment rate in June was 12.4 percent, the highest in the nation.
Economic downturns are likely to send adult children back to their parents' homes, often with the grandchildren in tow, while spousal loss and declining health can push parents into the homes of their adult children, according to a University of Nevada, Las Vegas sociology study from August 2010.
The study predicted that Nevada's ongoing economic recession and housing crises would have profound effects on household relationships and encourage more multigenerational living.
Paul Bell, a longtime real estate agent in southern Nevada and president of the Greater Las Vegas Association of Realtors, said he has observed more grandchildren and children moving home to help their aging grandparents and parents.
Recent graduates are also returning home to save money, Bell said.
"The unemployment rate is definitely having that type of impact," he said.