The Role Of Metrology In Reconstructing The Giza Pyramids

By John Oncea, Editor

Modern metrology – GNSS, laser scanning, BIM, and automation – would enable precise and efficient rebuilding of the Giza pyramids far faster and with fewer resources.

The first pyramid the Egyptians ever built was near Memphis. No, not this one, though if you’re interested in learning about it, listen to this episode of 99% Invisible.

The pyramid I’m talking about – the Step Pyramid of Djoser – is located in Saqqara, Egypt, and was constructed for Pharaoh Djoser around 2780 BCE. Up until this point, Egyptian kings were buried in bench-shaped mounds called mastabas, which is the design that Djoser’s tomb started as.

However, through a series of expansions, it evolved into a 197-foot-high pyramid with six layers, one built on top of the other. Designed and built by Imhotep, “The pyramid was constructed using 11.6 million cubic feet of stone and clay,” Live Science writes. “The tunnels beneath the pyramid form a labyrinth about 3.5 miles long, and it was covered with tura limestone, most of which is gone today.”

According to the Smithsonian, Imhotep placed “six mastabas, each smaller than the one beneath, in a stack to form a pyramid rising in steps.” The transition to a true, smooth-sided pyramid occurred during the reign of King Snefru, the founder of the Fourth Dynasty (2680–2560 BCE). At Medum, a step pyramid was constructed, then filled in with stone and covered with a limestone casing.

Nearby, at Dahshur, construction began on a pyramid intended to have smooth sides. However, midway through its construction, the angle of inclination was adjusted from over 51 degrees to about 43 degrees, resulting in a less steep appearance, a change that led it to be known as the Bent Pyramid. Another pyramid was built at Dahshur with sides that rise at an angle slightly greater than 43 degrees, resulting in a true pyramid, albeit with a squat appearance.

Egyptian pyramids evolved over the ensuing years, culminating with the Great Pyramid at Giza, the largest and most famous of all. It was commissioned by Snefru’s son, Khufu, and had a base covering over 13 acres and sides over 755 feet long that rose at an angle of 51 degrees 52 minutes.

“It originally stood over 481 feet high; today it is 450 feet high,” Smithsonian writes. “Scientists estimate that its stone blocks average over two tons apiece, with the largest weighing as much as fifteen tons each. Two other major pyramids were built at Giza, for Khufu’s son, King Khafre, and a successor of Khafre, Menkaure. Also located at Giza is the famous Sphinx, a massive statue of a lion with a human head, carved during the time of Khafre.”

Building The Great Pyramid At Giza

Much of how the Egyptians built pyramids is unknown, though it is speculated that they used copper chisels, drills, and saws to cut the relatively soft limestone blocks. The much harder granite used in the burial chamber walls and some exterior casing might have required the combination of tools with abrasive powders like sand to aid the process.

Astronomical knowledge was essential for aligning the pyramids precisely with the cardinal points. To ensure a level foundation, builders probably used water-filled trenches around the perimeter.

Tomb paintings depict colossal statues being transported on sledges, which were dragged over ground made slick with liquid, illustrating how massive stone blocks were moved. These blocks were then hauled up ramps to their designated positions within the pyramid. The outer casing stones were finished from the top downward, with ramps dismantled as construction progressed.

Most of the stone used for the Giza pyramids was quarried locally on the Giza plateau. Some of the fine limestone casing came from Tura, across the Nile, and granite for certain chambers was sourced from Aswan.

Quarry worker marks, including the names of work gangs like “craftsman-gang,” have been found on several blocks. The workforce likely consisted of skilled masons and laborers working year-round, supplemented by part-time crews during peak periods.

The Greek historian Herodotus wrote in the fifth century BCE that, according to his Egyptian guides, 100,000 men worked for three months each year over twenty years to build the Great Pyramid. However, modern estimates suggest a much smaller labor force.

Pyramid construction reached its peak between the Fourth and Sixth Dynasties, though smaller pyramids continued to be built for over a thousand years. Many have been discovered, while others remain hidden beneath the sands.

As it became evident that pyramids failed to protect royal mummies from grave robbers, later pharaohs chose to be buried in concealed rock-cut tombs. Despite not safeguarding the bodies of the kings, the pyramids have ensured that their names and stories endure to this day.

Building The Great Pyramids Of Giza Today

Metrology underpins every stage of modern construction, ensuring precision, efficiency, and quality that far surpass ancient methods. If the Great Pyramids of Giza were to be built today, metrology, along with modern engineering and materials science, would transform the process from start to finish.

The construction of a pyramid on the scale of Khufu’s would likely use reinforced concrete rather than quarried limestone and granite. This would dramatically simplify logistics, reduce costs, and speed up construction.

For example, using concrete, as was done in projects like the Hoover Dam, would require about 1.9 million cubic meters of material, with embedded cooling pipes to manage heat during curing, How Stuff Works writes. Such a project could be completed for an estimated $250–$300 million, making it feasible for large-scale commercial or commemorative ventures.

Cranes, excavators, and automated transport vehicles would replace human and animal labor. Large blocks or pre-cast panels could be manufactured off-site to exact specifications and assembled with millimeter accuracy, eliminating the need for massive ramps or human-pulled sledges.

The original pyramids are renowned for their precise alignment and level bases, something that would be elevated even further using modern metrology. 3dfindit writes that surveyors would use GNSS (including GPS, GLONASS, and Galileo) to establish the pyramid’s footprint with centimeter-level accuracy, ensuring the base is perfectly square and aligned to true north. Laser total stations and 3D laser scanners, instruments that measure distances, angles, and elevations to within fractions of a millimeter, would map the site, create digital terrain models, and guide the layout of foundations, guaranteeing a level base and perfect geometry.

Instead of water-filled trenches, digital and laser levels would provide real-time feedback to ensure the entire base is flat and well within a millimeter over hundreds of meters. Finally, automated robotic total stations would continuously monitor the site, adjusting construction in real time to maintain alignment as the structure rises.

To maintain dimensional control, 3D modeling and building information modeling (BIM) would be used. Every block or panel would be designed in a digital model before construction, and BIM systems would track each component’s dimensions, position, and installation sequence, minimizing errors and rework.

After each construction phase, 3D laser scans would compare the as-built structure to the digital model, ensuring deviations are immediately identified and corrected. In addition, modern metrology, including ultrasonic, radiographic, and other non-destructive testing (NDT) methods, would be used to verify the integrity of concrete or stone, ensuring that every component meets strict standards for strength and durability.

Then there are tower cranes and automated guided vehicles (AGVs) that would be used to transport and position massive blocks or panels with pinpoint accuracy, guided by laser targets and real-time feedback from total stations. Drones equipped with cameras and LIDAR would monitor progress from above, feeding data back to project managers for instant analysis.

Ground penetrating radar (GPR) would be used before construction to map subsurface conditions, ensuring the foundation is secure and identifying any voids or weak zones. Finally, sensors embedded in the structure and foundation would track settlement, temperature, and other variables, alerting engineers to any issues before they become critical.

Metrology in Finishing and Cladding

The original pyramids’ smooth casing and tight joints are legendary. Today, CNC-machined stone or engineered panels would be manufactured to tolerances of less than a millimeter and installed using laser-guided systems for perfect fit and finish.

With automation and modern metrology, the workforce would be a fraction of the ancient labor armies. Skilled engineers, surveyors, and machine operators would replace thousands of manual laborers, and the entire project could be completed in a few years rather than decades.

Recent studies underscore the ingenuity of ancient methods, such as the use of ramps and geometric layout techniques, but also highlight their limitations in precision and efficiency, Mechanical & Aerospace Engineering concludes. Modern metrology would eliminate the guesswork, ensuring every aspect of the pyramid-from the orientation to the final capstone, is executed with scientific accuracy.

Rebuilding the Giza pyramids today would be a marvel of modern engineering, made possible by advanced metrology. From GNSS and laser scanning to BIM and automated construction, today’s tools would deliver a structure even more precise than the ancient originals, completed in a fraction of the time and with far fewer resources. The combination of ancient inspiration and modern technology would not only honor the achievements of the past but also showcase the possibilities of the present.