conceptual drawing at completion; artist's impression of completed building
Used for architectural or construction projects to show what the finished building will look like.
The conceptual drawing of the new station at completion was released.
Looking at the artist's impression, it has a very modern design.
完成図 is a drawing of the completed state, but 完成予想図 specifically emphasizes that it is a predicted or planned image before construction.
イメージ図 is a broader term for any conceptual image, while 完成予想図 is specifically for the completed state of a building or structure.
Compound of 完成 (completion), 予想 (prediction/expectation), and 図 (drawing/diagram).