My mansion would be built like a Roman Villa...with a garden in the center/perhaps a fountain and rooms for living all around.
The section furthemost from the entrance would have more than one story, with a third story/study/observatory like tower.
My manse would also have a small theater in it with a popcorn and a soda machine on the first floor somewhere...perhaps in the West wing. Bedrooms would be beneath the tower and the Kitchen and den would be in the East Wing; with a service entrance their. The formal "Living Room would be in the West
Aperatures would be large as i love wind and light.
An American poet named Robinson Jeffers (one of my favorites) built a stone Tower he called Hawk Tower and his house was called Tor House. So I might want to make a Tower separate from the house.
If I did that them the far end of the house would have just two strories, with the Master Bedroom surveying the interior garden. There would be a balcony of course.
I would also study some true Roman designs before I proceeded with the final design with an eye toward fusing Roman ideas into my own desires.
Jeffers link:
http://www.torhouse.org/(sigh)
Ave Caesar
No bitterness: our ancestors did it.
They were only ignorant and hopeful, they wanted freedom but wealth too.
Their children will learn to hope for a Caesar.
Or rather--for we are not aquiline Romans but soft mixed colonists--
Some kindly Sicilian tyrant who'll keep
Poverty and Carthage off until the Romans arrive,
We are easy to manage, a gregarious people,
Full of sentiment, clever at mechanics, and we love our luxuries.
Robinson Jeffers