Dive Brief:

• Digital 3D scans taken by an art history professor in 2015 may prove critical in efforts to rebuild the Notre Dame Cathedral in Paris, France, which lost its spire and much of its roof to a fire last week. The 850-year-old landmark was undergoing renovations when the fire broke out, and police investigators have suggested an electrical short-circuit is to blame.
• The late Andrew Tallon of New York’s Vassar College, along with colleagues, recorded more than 1 billion points of data on the structure in 2015 using a tripod-mounted Leica ScanStation C10 laser, reported Engineering News-Record.
• The scans, which were layered with high-resolution panoramic photos, could reportedly shorten the reconstruction time frame by providing an AEC team a highly accurate digital blueprint for the structure, for which hand drawings may not be available.

Dive Insight:

Another construction technology that could prove useful in the aftermath of the 15-hour blaze is a time-lapse camera that was installed on a bell tower just hours before it broke out. The footage is being reviewed by investigators, a scaffolding contractor on the renovation told Reuters.

French President Emmanuel Macron has called for the Gothic cathedral to be rebuilt in five years and in time for the 2024 Summer Olympics in Paris, reported AP, but restoration experts have challenged this timeline and said the undertaking could require more than a decade.

The wooden spire was a relatively recent (19th century) addition to Notre Dame Cathedral, which is composed of 12th, 13th, 14th and 19th century components. If designers, engineers and contractors go off of the original design, Tallon’s laser scans can provide important geometry and assist in correcting errors from earlier restorations, according to the ENR report. But they will have to dig deeper to get a sense of how the structure was assembled, and finding oak timbers the size of what was originally used for the roof would be nearly impossible, experts told ENR.

However, French officials may opt for a redesign that is different from the structure destroyed in the fire. Macron said the spire would be rebuilt “even more beautifully,” while French Prime Minister Edouard Philippe called for “a new spire that is adapted to the techniques and the challenges of our era,” reported BBC. He launched an international design contest for the replacement of the spire, leaving open the possibility that the Gothic cathedral could be topped with modern construction. Some suggestions, for example, include a crystal glass spire supported by stainless steel and a glass roof to illuminate the sanctuary.