To convert the stable into living space, you invest a lot of money. What happens to the old roof?
You also need to insulate the ceiling.
Is it possible as is to convert a floor into living space and the upper floors do not meet fire protection standards?
As a layperson, I could imagine that demolition and rebuilding might not be much more expensive.
It's not like there is a finished shell standing. You need windows, doors, possibly support beams, ceiling insulation, walls, interior walls, maintenance of the rest of the building, and the interior finishing yourself. You have a lot of space that is partly difficult to use. That results in the convoluted huge unusable bathrooms or a guest toilet only suitable for athletic people.