ROOFTOPIA means utopia on the roof. This design is a tile-shaped bird's nest module made of recycled wheat straw, which provides shelter and protection for birds under the same sky. Wheat straw is an agricultural waste with high yield and wide source, but shows good biophilic properties and sustainability. The tile-type artificial nest box adopts modular construction form to mold the recycled wheat straw that birds like to inhabit, to help create environmentally friendly urban buildings. It is hoped that more birds can comfortably perch on the eaves and enjoy the urban sky as humans do.