Home vacancies and the nation’s homeownership rate were roughly flat in the first quarter of 2011 compared to the same quarter last year, according to U.S. Census data released this week.

The rate of home vacancies, at 2.6 percent, was unchanged compared to first-quarter 2010, though was well above levels seen before the beginning of the housing downturn in 2005, when it hit 2 percent for the first time since before 1996.

The U.S. homeownership rate, which government policies had helped boost to the brink of 70 percent by 2004, sat at 66.4 percent in the first quarter, down a slight and statistically insignificant 0.7 percent since the first quarter of 2010.

The rental vacancy rate in principal cities — the Census Bureau defines a principal city as the largest city in a given metropolitan or “micropolitan” area — was 9.8 percent, in the suburbs it was 9.3 percent, and outside of metropolitan statistical areas (MSAs) it was 10 percent. The differences were not statistically significant, the Census Bureau said.

Homeowner vacancy rates, however, did vary by location. In principal cities, the rate stood at 3.2 percent, significantly higher than the rates in suburbs and outside MSAs, which had rates of 2.4 percent and 2.3 percent, respectively.

Regionally, the rental vacancy rate was higher in the South (13.2 percent) and the Midwest (11 percent) and lower in the Northeast (7.5 percent) and the West (9 percent).

The same pattern fit homeowner vacancy rates, with the South (2.8 percent) and Midwest (2.7 percent) statistically similar, with the West (2.4 percent) and Northeast (2.2 percent) falling close to each other.

The report also included estimates of the total housing inventory in the U.S., showing an increase of 659,000 units, to 131 million units, between the first quarter of 2010 and 2011.

There was a decrease in vacant homes from last year by 99,000, according to the estimates. The number of vacant homes for sale climbed by only 2,000 on a year-over-year basis. Correspondingly, the number of vacant homes held off the market increased by 270,000, taking the total from 7.1 million to 7.37 million.

At the same time, the number of homes vacant for rent declined by 338,000, to just over 4 million.