We visited a site on the outskirts of Paris, France in the fall of 2017, and we had a strong impression on the curved surface of the windscreen wall of the solarium on the roof and the spiral staircase extending from the center of the entrance hall. Corbusier also left wood carvings, but he never designed a wooden door handle. If we collaborated with him, it might have become such a design that the door mounting part and the handgrip part lead to a large radius and an obtuse angle. Hardwood is shaved, polished and finished with oil. It's like a book with the left and right door handles aligned. We want everyone to enjoy the wood grain drawn on the page of the book.