Here's my guess at last.
If you look at the plan below the roof model, I started using the rear slope (7:12) to complete the front high roof as indicated in previous posts. However I thought this looked worse so I changed it in the model to be 12:12 all sides of the front high roof. I also dropped the garage roof eave in the model, as I think this makes the symmetrical part work better. However that requires that you push the door wall of the garage out a little (no big deal), so the resulting roof works with the master bedroom roof.
I left the "terrace" uncovered. I think that is a better design and creates the roof ridge of the central 7:12 in accordance with the elevation (not so high). Besides the plan has a dotted line at the "porch" indicating it is covered perhaps and the "terrace" is not. I scaled off the graphic and I think my roof is scaled different than yours, but the concept is there.
The top of the high front roof is not to be flat really. You'd have a low slope in four directions, but you'd not see it really. Or a skylight with a dramatic shaft in the great room.
OK-- so I see in yours the high pitch is only on two sides, that makes the ridge for the front element work. That looks pretty good. I wonder though if you can make the lower roof each side of that have more ridge and be symmetrical, plan allowing, to create a better visual support for the high roof. Good luck. Peter
House-plans B.skp