Outbuilding – Noun 1.

8×12 Lifestyle Modular Backyard Office

1. A building that is subordinate to and separate from a main building
2. A structure not connected with the primary residence on a parcel of property. This may include a shed, garage, barn, cabana, pool house, outhouse or cottage.
3. A building separate from but associated with a main building.

First Known Use 1626