Hallo !
in Lübeck many old buildings have a 1/2 level at the buttom (http://de.wikipedia.org/wiki/Geschoss_%28Architektur%29#Sockelgeschoss) - in German Hochparterre mit einem Sockelgeschoss.
how to define the level-tag ? level 2.5 if you have to go a step to to the first level ?
regards Jan .-)