It would actually make a good barn if the roof was changed to a gambrel running the length. Many barns are built on hills like that and would have similar door placement. Here's some source pictures.
This is the gambrel roof. Adding a silo would add height and a small bump-out structure would make it more interesting without changing how it plays.
Here's a barn from similar perspective, except it doesn't have the gambrel, which is generally the defining factor of a barn.
Many barns also have cupolas, which would be another easy addition for detail.
I'd sketch it, but I think you get the idea.

Disclaimer: I live in Wisconsin, so a barn is naturally the first thing I thought of. :/