Forget years of falling prices, recent record low mortgage rates, and tax credits that help offset the cost of buying a home.

What may appear to be favorable market conditions for putting a roof over your head hasn't been enough to offset the high cost of housing for tens of millions of Americans.

From 2005 to 2008, more households have been added to the ranks of those that spend more than 30 percent or more of their income on housing and households that can least afford the extra cost suffer most, according to "Housing Affordability Trends for Working Households" a new report from the Center for Housing Policy.

Between 2005 and 2008:

• The share of all U.S. households with a "severe housing cost burden" rose from 14 to 15 percent. Households with a severe housing cost burden are those that spend more than 50 percent of their income on housing costs, including utilities.

• The share of all U.S. households with a "moderate housing cost burden" rose from 18 to 19 percent. Households with a moderate housing cost burdens spend 31 percent to 50 percent of their income on housing.

• The share of all "working households" with a severe housing cost burden increased from 20 to 21 percent over the three year period. A working household is one in which members combined to work at least 20 hours per week and on average have a total income at or below 120 percent of their area's median income. Working households account for more than 47 million households and 40 percent of the nation's population.

• The share of working home owners with a severe housing cost burden rose the most, from 18 to 20 percent, while working renters' numbers remained at 22 percent.

Working households often provide essential services the nation relies upon, including work in schools, public safety, retail sales and food service, among other blue and pink collar service industries.

The report said the increase in the number of housing cost burdened households was due largely to higher utility costs which rose by nearly 23 percent, or more than double the rate of inflation.

Also, most homeowners have not moved since the housing crisis started so they have not benefited from lower prices, but many have suffered interest rate adjustments that have resulted in higher mortgage payments.

Reduced employment and unemployment has also taken a toll.

Now, rising home prices could further take a toll on affordability.

Download Housing Affordability Trends for Working Households.

Published: January 21, 2010

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A journalist for 35-years, Broderick Perkins parlayed an old-school daily newspaper career into a digital news service offering editorial content and consulting services. Perkins' San Jose, CA-based DeadlineNews Group includes the flagship news site, DeadlineNews.Com, offering real estate, personal finance and consumer journalism, and a backshop, the Deadline Newsroom.