I found this interesting in terms of the age of houses in Jacksonville compared to other cities around the USA:
Housing units Built 2005 or later Percent Rank Built 1969 or earlier Percent Rank
Jacksonville, FL 598,524 64,813 10.83% 14 156,949 26.22% 78
http://www.bizjournals.com/bizjournals/on-numbers/scott-thomas/2012/06/austin-has-newest-housing-stock-in-the.html?ana=RSS&s=article_search&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+industry_21+%28Industry+Residential+Real+Estate%29 (http://www.bizjournals.com/bizjournals/on-numbers/scott-thomas/2012/06/austin-has-newest-housing-stock-in-the.html?ana=RSS&s=article_search&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+industry_21+%28Industry+Residential+Real+Estate%29)