House Buried in Terrain

[Evergreen Bldrs]

Hi all,

I am very new to Home Designer Pro 2014. In fact this is my first house. I love it so far, but have run into an issue. I created my terrain with appropriate contour lines. Now, my garage is buried by the terrain.

I think when I create a flattened area it must be tied to the elevation of the highest contour line within the flattened area.
So.....when I draw a small flattened area it is the correct height in relation to the house, but when I make the area bigger (moving it into higher ground) it automatically raises the flattened area so half of the wall is now covered.
What am I doing wrong?

I've watched the training videos but to now avail. Thanks for any help so my provide!

Jeff