Stam,
Is them outside boards T&G (tongue and groove) or shiplap? My eye's cant tell from the picture. Exactly what pitch is the roof? How wide, how deep and how tall is that thing? What are the measurements of the door? Did you make it as air tight as possible? Did you concrete the four corners in the ground? Did you use treated posts in the corners?

Thanks

I'll probable have more questions as I get started.