There's also LiDAR data you can find/use. If you're lucky enough to find also CAD that would be great.
http://isiforums.net/f/showthread.php/22897-Emery-s-Public-LiDAR-Database?highlight=
http://isiforums.net/f/showthread.php/22897-Emery-s-Public-LiDAR-Database?highlight=