Awesome way to do a "guest room" if your house is too small. This started out as a shed. They added the porch, salvaged cottage windows and split shingle roof. would love this just as a garden shed or reading area
Reuse an old tree to make a log pathway in your garden. Good use of "yard" trees and other wood that can't be milled; works much better in climates without termites. Good drainage under the log rounds will make the path last longer.
Would make a terrific mudroom entrance --- hooks for jackets, baskets for hats/mittens/hiking gear, etc. A bench to put on/take off shoes. The corner windows are a nice touch. The room has such a warm feeling to it.