Lean-To+Room

noun: lean-to; plural: lean-tos
 * Lean-To Room**
 * A building sharing one wall with a larger building, and having a roof that leans against that wall.
 * A temporary shelter, either supported or freestanding.

Lean-to is a simple structure originally added to an existing building with the rafters "leaning" against another wall.

//"She slept in a leanto room at the back of the house. It had a window which she learned to open and close again in the dark without making a sound, even though there also slept in the leanto room at first her oldest nephew and then the tow oldest and then the three"// (LIA 5).

[Carla Scollo]