No. 39 Shamian Street, a century old building, is also a coordinate. From the original Sassoon House to the later French Mission Building. In the long history, different people have operated or lived here. The appearance of the building has changed with many factors, and the connotation of this coordinate has also changed. Now, it is integrated into modern life in the form of cafes and open to the public, becoming a new way for people to experience the humanistic spirit of Shamian cultural relics and buildings. The building at No. 39 Shamian Street has the style of western neoclassicism (provided by the interviewees). Restart: look for the original appearance according to clues. "For this building with a history of more than 160 years, we may be just passers-by, but we are obligated to repair it completely, so that it can move towards the next 160 years in a more beautiful manner." Deng Ziyang, the founder of Back and forth Coffee, said frankly that he chose to settle in Shamian because he wanted to explore the beauty of century old buildings with people. More than a year ago, the "back and forth" repair team stepped into the building and found that the interior of the building was very complex and chaotic; Many turbulence and changes in a hundred years of history make its internal structure far different from its original design plan. Through consulting historical materials and relevant research, designers learned about the tortuous history of this old building: this building has a typical western neo classicism style, its original identity was Sassoon Foreign Firm, and after several changes of ownership, it was once a French missionary office building and a new ambition foreign firm. As time goes by, the original materials of the building have long been lost and cannot be obtained. This did not dampen their enthusiasm for "restoring" the original appearance of the building: if they could not find the original materials to repair, they could at least find clues according to the current situation, reason about details like "solving a case", and restore the original appearance of the building to a certain extent. The first and second floors of No. 39 Shamian Street have been opened to the public. Some original doors and windows in the building have been removed as part of the partition wall. At first, these were almost indistinguishable. Through the analysis of the internal frame structure, the designer keenly found the added parts. After the surface was removed, the doors and windows originally belonging to the building itself were stripped out. Then, the original positions of these doors and windows were judged through the associated space components. However, not every "saved" component can continue to be used. If the damage is serious, it can only be reproduced one by one according to the size and style. The new floor tiles should match the damaged floor tiles in the old bricks (provided by the interviewees) as much as possible in color and wear degree, and it is impossible to verify its material and source. After many inquiries, the repair team found a factory that can customize new floor tiles with consistent appearance. After special treatment, the new floor tiles should match the old ones in color and wear as much as possible, but the repaired parts should be slightly different from the existing ones, which can be recognized by professionals and conform to the principle of "identifiability" in the restoration of buildings and cultural relics. The nostalgic revolving wooden staircase emits a lingering ancient charm of rebirth: let it integrate into modern life, and after more than a year of "no cost" repair, it looks like a rebirth of the sand street