The ARC with most of the wallpapering/flooring done

Maybe a private retreat for the owners to get away from the business for awhile. A little fencing and some shrubbery to hide it all and voila !

Or - add an outside stairway and create a outdoor eating patio for the customers. Some umbrellas and café tables and you're all set.

Thanks for the ideas, Selkie! I like the idea of an outside stairway. I was considering some sort of eating area with small tables, but I'm still feeling quite indecisive at this point.