Philadelphia residents are experiencing a lack of available apartment units, particularly for low-income residents.

Prior to the recession, many apartments in the metro area were converted to condominiums and developer efforts focused on building single-family housing, the Philadelphia Inquirer reports. In the suburbs, the availability of land parcels of an appropriate size was limited, and some locals opposed rental construction.

In and around Philadelphia, renters in the low- and middle-income segments of the population are most affected by the shortage, according to a recent study by the National Low Income Housing Coalition and the Housing Alliance of Pennsylvania. While less able to cope with rising prices, these groups are more numerous and more heavily impacted by the current situation.

Pennsylvania is only the 21st-most-expensive state, the news source notes. This suggests that owners and rental property management firms who are able to provide affordable housing units at reasonable prices will likely have little trouble filling them with renters in many areas of the nation. The most-expensive state is Hawaii, while Puerto Rico was found to be the least-expensive area measured, after all of the states and the nation's capital.