Nationwide, based only on housing affordability, 76% of U.S. communities are affordable for the regional typical households. However, once transportation costs are included, the percentage of affordable housing drops to 28% for the regional typical household making their area’s median income.

Housing is considered affordable when no more than 30% of a household’s income is spent on housing. This does not take into account transportation costs which are usually the 2nd largest expense in any household. A more complete measure of affordability combines housing and transportation costs which should take up no more than 45% of a household budget. The Center for Neighborhood Technology (CNT) has updated their Housing + Transportation (H + T) Affordability Index with American Community Survey 2009 5-year estimates, and now covers 900 metropolitan and micropolitan areas across the country – almost 180,000 neighborhoods and 89% of the U.S. population.

Below is a comparison of the difference between the percentage of affordable housing alone vs. affordable housing and transportation in CT based on county, according to the H + T Affordability Index.

                                           Housing Cost Only <30%              H + T Cost <45%

Fairfield County                        5.4% affordable                      42.5% affordable
Hartford County                       79.4% affordable                      48.6% affordable
Litchfield County                     81.9% affordable                      31.4% affordable
Middlesex County                   65.1% affordable                      22.2% affordable
New Haven County                 63.4% affordable                      26.7% affordable
New London County               80.2% affordable                       31% affordable
Tolland County                         72.7% affordable                       21.5% affordable
Windham County                     85.9% affordable                       16.6% affordable

Since the 2000 Census, housing and transportation costs have increased at a greater rate than incomes have in that same time: from 2000 to 2009, median housing costs  increased by 37% and average transportation costs increased by 40%, but median income increased by just 22%.  Interestingly, the H + T Affordability Index shows that inefficient neighborhoods- neighborhoods where transportation costs were greater than 15% of national median income - had an average increase in transportation costs that were twice that of transit oriented areas (access to transit, jobs, etc) - areas where transportation was less than 15% of the national median income.

For the CNT article about the Index go here. 
The H+T Affordability Index is located here.