Here is my proposal for your villa.
For me this was a delicate play of finding the right balance and the right proportion of space, that would provide a good relation between the open and the private, between the interior and the landscape, between the light and the shadow.
Positioning and orientation of all of the living spaces in the house are defined and optimized in a way that allows all of them to receive the best quality daylight during the entire year.
The service spaces are tucked away and they also serve as buffers between the the living-room area and the bedrooms. Thus, the privacy of the bedroom is never directly exposed to the view and sound of the living area. The living area in contrast, is fluid, open, three-dimensional and dynamic.
Contrary to your wishes, I have positioned the garage on the ground floor, instead of the basement. A ramp that would be functional would consume too much of the valuable garden space. It would also strongly influence the positioning of the house on the lot, by pushing the house towards the south, and opening up the lot on the useless north side. This way, the garage is made as a porch, in direct link to the main entrance (wardrobe) and the service entrance (pantry and kitchen). Apart from saving a lot of money on the underground garage and expensive driveway, I believe this way, you also get a better functional solution. With this solution, you are also free to decide weather or not you want to have the leisure spaces in the basement, without having to redesign the whole project.
The whole structure is consequently inscribed within a regular 90x90cm raster, which allows for execution of affordable and rational timber construction.