Gardening shed. Construct a cute garden shed in a weekend with a kit. Prefab wall panels go up quickly, and doors and windows slip into precut openings. Dress it up with hanging baskets suspended from beams and window boxes overflowing with flowers.
This is beautiful. From the look of the kitchen island and the bar stools, the kitchen is likely to be nicely done as well. I like the loft for a guest room. I would also consider sliding barn doors as a separation for the bedroom.