How to create a split level house?

[gracefr]

I am trying to design a house on a sloped lot. I choose to use a split-level house. The first floor will be on the lower part of the land. The second floor is above the first floor but part of the second floor is on the higher part of the lot.

How do I
1) Setup this terrain (slope)
2) Build the second floor so that part of it is above the first floor while the other part is on the higher part of the lot.

Novice user thanking you,
Grace