Above, Notre Dame de Paris as seen by Childe Hassam in 1888.
“An Architecture Student’s Project Made Notre Dame’s Restoration Possible” by Rain Noe touches on several issues in the philosophy of historic preservation. First, as suggested by the title, the fact that someone had measured the entire roof structure of the cathedral before its devastating fire, and had turned those measurements into CAD drawings, is playing a vital role in the current reconstruction. It might have been possible with Rémi Fromont’s drawings, but they obviously are making the work simpler.
The second issue is that the roof structure is being rebuilt as it was, without any changes that might be suggested by, for example, modern structural analysis. Fromont’s explanation is that the existing design is known to have worked for a very long time, so changing it is a risk that there is no good reason to take. I generally agree with that logic. I wouldn’t be surprised if there has also been some structural analysis to back it up: I’d agree with the logic regardless because I favor empirical performance over modeling, but if there’s a model showing that the heavy timber roof frames work for stress, it’s an even easier choice to make.
Finally, there’s the issue of technique. The carpentry is being done using tools similar to those used in the Middle Ages to build the old roof. There’s nothing inherently wrong with that, although one could argue that it will make it difficult in the future to properly date the new work by blurring the distinction between new and old…if one were to ignore the incredible fame of the building and the degree to which the work is being documented. On the other hand, it seems unnecessary. A cut mortice is a cut mortice, and I don’t see an advantage to using the old tools, other than a psychological one.
