Thanks for the reply! I like what you're saying about shadowing a localized spot where there's a change; the stairs for example. As to keeping the maps separate, I didn't explain the particular use I'm going to be putting these buildings to, but they are for a skirmish game (Mordheim) played on a virtual table-top, so there's a lot less exploration and more finding the perfect nook to put a crossbow sniper. I think I'll favour utility over aesthetics in this particular case and just use the same shadow effect for each level and accept that it won't look ideal but will get the required information across.

Again, thanks for the tip.

cheers,
Meshon