Jean-Pierre Houdin (French: [udɛ̃]; born 1951) is a French architect. He created a theory explaining how the Great Pyramid of Giza was built. His theory suggests an external ramp was used to construct the lower part of the pyramid. Then, an internal spiral ramp was used to build the upper part.

Pyramid construction theory

In 1999, Houdin's father, a retired civil engineer, began working on an idea that the pyramids were built from the inside. Jean-Pierre Houdin used advanced 3D modeling technology to help his father discover a construction unusual feature they called "the spiral structure." This feature looked like a ramp inside the pyramid, which they believed might have helped in its construction. In 2003, his father created the Association of the Construction of the Great Pyramid (ACGP) to support the project. This group helped him connect with other experts.

In 2005, Mehdi Tayoubi and Richard Breitner from Dassault Systèmes invited Houdin to join a new program called “Passion For Innovation.” Together, they studied the theory using Dassault Systèmes’s 3D technology for industrial and scientific purposes.

Using software like CATIA, they recreated the pyramid’s construction in three dimensions. This allowed them to test whether the spiral structure could have been used. To share their findings, Tayoubi and his team used 3D technology to create an interactive journey through time. This was shown on the giant screen of La Géode, a famous theater in Paris, and online.

Also in 2005, a project began to study cracks in the King’s Chamber of the pyramid. The team included Houdin, Egyptologist Bob Brier, Tayoubi, Breitner, and engineers from Dassault Systèmes. They used software like SIMULIA, which is typically used by companies to test product designs and find structural weaknesses.

Their plan suggested using an external ramp to build the first 30% of the pyramid, then switching to an internal ramp to move stones higher. The stones from the external ramp were reused in the upper parts, explaining why no ramp remains visible.

After working alone for four years, Houdin joined engineers from Dassault Systèmes, who used modern computer-aided design tools to test the theory further. Houdin claimed this was the only proven method to build the pyramid. He wrote about his theory in books published in 2006 and 2008.

In Houdin’s method, each internal ramp ended at an open space, a temporary gap in the pyramid’s walls. This space held a crane that lifted and rotated 2.5-ton stone blocks, making them easier to move up the next ramp. In 2008, Bob Brier and a National Geographic team discovered a previously unknown chamber that might mark the start of an internal ramp. In 1986, a member of a French team saw a desert fox near this gap, as if it had climbed inside.

Houdin’s theory has not been proven. In 2007, David Jeffreys of University College London called the spiral structure idea “far-fetched and overly complex,” while John Baines of Oxford University said he was “suspicious of any theory that only explains how the pyramid was built.”

The team concluded that the pyramid’s architect, Hemiunu, worried about cracks threatening the structure, carved a tunnel above the burial chamber to check the damage. He then filled the cracks with plaster to monitor if they widened. The beams held, and the pyramid was completed.

In popular culture

In the 2017 video game Assassin's Creed Origins, a tour of the Great Pyramid of Giza that follows Jean-Pierre Houdin's internal ramp theory is included.