Click image for larger version. 

Name:	tower-keep-page-01-650a.png 
Views:	93 
Size:	426.8 KB 
ID:	66657

Steps up to a platform, drawbridge to an attached platform. Voila.
So this would make the 'Basement' the actual ground level.

Five stories above ground - would look epic considering that most houses in a medieval town were like 1.5-ish.

Thanks Madcowchef.

-GP