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, and an internal spiral ramp was used for the upper part.

Pyramid construction theory

In 1999, Houdin’s father, a retired civil engineer, began developing the idea that the pyramids were built from the inside. Jean-Pierre Houdin used 3D modeling technology to help his father discover a construction 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, Houdin’s father formed the Association of the Construction of the Great Pyramid (ACGP) to support the project. This group helped him connect with experts.

In 2005, Mehdi Tayoubi and Richard Breitner from Dassault Systèmes invited Houdin to join a program called “Passion For Innovation.” Together, they studied Houdin’s theory using Dassault Systèmes’ 3D technology. They used software like CATIA to recreate the pyramid’s construction in 3D. This allowed them to test whether the spiral ramp idea was possible. To share their findings, Tayoubi and his team used 3D technology to create an interactive experience. This was shown on the giant screen of La Géode in Paris and on the Internet.

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 for weaknesses.

Their plan involved using an external ramp to build the first 30% of the pyramid. After that, an internal ramp would carry stones upward. The stones from the external ramp were reused in the upper parts of the pyramid, explaining why no ramp remains visible today.

After working alone for four years, Houdin joined engineers from Dassault Systèmes. They used modern computer-aided design tools to improve and test the theory. Houdin said this was the only proven method for building the pyramid. He wrote about his theory in books published in 2006 and 2008, including Khufu: The Secrets Behind the Building of the Great Pyramid and The Secret of the Great Pyramid, co-written with Bob Brier.

In Houdin’s method, each internal ramp ended at an open space, a temporary gap in the pyramid’s edge. 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 explored a previously unknown chamber that might be the start of an internal ramp. In 1986, a member of the French team saw a desert fox at this gap, as if it had climbed inside the pyramid.

Houdin’s theory has not been proven. In 2007, David Jeffreys from University College London called the spiral ramp idea “far-fetched and overly complex,” while John Baines from 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. He made a tunnel above the burial chamber to check the damage and filled the cracks with plaster to monitor if they were getting worse. The beams held, and the pyramid was completed.