I see that your question has been without an answer for more than a month, so, this information comes too late for you. But anyway,...

1) Bring your sketch as an image to an elevation view in the generic adaptive template (or in the mass template if you are interested in creating mass floors and schedules).

2) In the elevation view, scale the image. You can use that human figure that you drew, as a reference for the scale.

3) Draw reference lines or splines tracing over the image, to form those closed shapes that you see on the second image.

4) Select those shapes, and do Create Form. Add other elements as necessary, voids if required, etc.

5) Load the family into a project, and convert faces to walls, floors, roofs, etc.

See post #2.