According to census data in the year 2000 there were 5,249,750 housing
unites in Pennsylvania. This represents a 6.3% from 4,938,140 in
1990.

Of those housing units, 4,012,005 were located in either urbanized
areas or urban clusters, and 1,237,745 were located in what is
classified as a rural area.

Homeownership rate in Pennsylvania is about 71.3%. Pennsylvania's
vacancy rate,
http://www.cnful.cn/pa/index.htm