Hello, I have a suggestion.
I believe compressing the rear roof into one tile high (maybe into the beam's tile) would make it look more natural.
Assuming the game's camera is at 45° and the roof slope is 30°, then the angle at which the camera "sees" the roof is 15°. Since sin15° ≈ 1/4, a rear roof covering 2 tiles in space should visually appear only 1/2 tile high.