2nd building 2nd floor?

[Notnam]

I've been working with Home Designer suite for a few days now and have created the first & second floor layouts for the main house.

However, I have a seperate two storey building (included in the plot but not attached to the main house) that I've started to layout now, but I can't form the second floor because the program is trying to create a 3rd floor on the main house!

I'm an absolute newbie at this and, of course, what I should have done is complete all building layouts/floors simultaneously, but if anyone can suggest a workaround and/or solution it would be most appreciated?

Many Thanks.