Would the attic be practical in your opinion or just a storage space?
Which attic do you mean now?
No, there is no particular reason for this construction, it is simply built like in the surrounding area...
In the area within this development plan’s scope, it is actually NOT built the way you envision. It’s best if you tell us about your construction project (the opening post sounds like a sketch at least already having a concrete room program), then you can be advised constructively. Don’t forget to put the completed questionnaire at the beginning of the story.