How much is she paying you to design your house?
Something like this? - pit on one side, solid on the other!
On special on that site - 4k for a 6m*5m roller shutter door version. Was in one recently, 9m*6m roller shutter to the front, side door, 6 cars at a squeeze. Nice bit of kit.
Rough concrete base, and Swisstrax Floor (shameless plug ) and jobs a good'un!