Building Outbuilding Seperate from Main House

[JHarbinson]

I am working on a plan where the main house is complete.  I am trying to create a separate outbuilding.  When I want to create a second floor on this building, the program adds a floor to the main house.  I only want to work on the outbuilding.  How do I separate the two as individual structures?

[Jo_Ann]

Allow the program to create a 2nd floor.

Move to the 2nd floor of the program, and delete the 2nd floor walls on the house.

[JHarbinson]

The main house is already 2 stories and is complete.  Creating a new floor causes the main house to add a third. 
 

Is there any way to only build a floor on the separate outbuilding?

[Robborito]

If you have a second floor - work away and build your other house.

Then you can elevate this second house to suit the levels of land/terrain.

Here's one I've been working on.

Jeff