This extension to a 17th century Cotswold cottage is designed as a flexible space that will allow the client to enjoy their garden setting all year round. The key design feature of this small extension is its glass walls which can disappear entirely behind three timber bookcases. The bookcases form the vertical structure of the building, supporting a cantilevered green roof. This design allows the walls of the building to vanish entirely, creating a surreal outdoor living room. The unsupported roof corner allows the space to flow into the garden, which has been transformed into a series of landscaped terraces.