The plan is a change from the concept announced last year of building a series of developments that would be linked by underground rail, the sources said. Current and former NEOM employees mentioned that designers were asked to create a prototype that could stretch half-a-mile.
In an entirely new $500 billion development dubbed NEOM, Saudi Arabia announced its intention to build the largest buildings in the world in a largely unpopulated region.
A Bloomberg report states that NEOM is the brainchild of the Saudi Crown Prince and de facto ruler Mohammed bin Salman. According to sources, Mohammed bin Salman plans to build twin skyscrapers about 500 metres (1520 feet) tall that stretch over dozens of thousands of meters.
Skyscrapers would stretch from the Red Sea coast into the desert, and would house housing, retail, and office space.
In contrast to the concept announced last year, in which a string of developments was linked by underground hyper-speed rail, the people say the plan envisions a continuous structure. Current and former NEOM employees said they were instructed to develop a prototype measuring a half-mile wide.
Every structure would be much larger than the world's largest buildings, which are usually factories or shopping malls instead of residential communities.
Prince Mohammed's plan to create a semi-autonomous high-tech state to reimagine urban life was first announced in 2017. Saudi Arabia's economic future depends on attracting foreign investment and diversifying its dependence on oil sales. NEOM's linear city - the backbone of which will be a car-free city - is estimated to cost as much as $200 billion to build, though this was before gigantic horizontal buildings were included in the plan.
"The Line has a very unique concept," Nadhmi Al-Nasr, chief executive officer at NEOM, said in an interview, declining to provide further details. We will present something revolutionary when we are ready to present it."
NEOM worked with a California architecture firm called Morphosis on The Line, according to former and current Saudi employees.
An Associated Press report said that Morphosis, founded by former "bad boy" of American architecture Thom Mayne, has not responded to requests for comment.
The buildings will change height as they progress, according to Al Nasr, depending on the terrain and engineering considerations.
Burj Khalifa, Dubai's tallest building, is already part of the Middle East skyline. Saudi Prince Alwaleed bin Talal announced before Prince Mohammed's rise that he was planning to build the tallest building in the world near Jeddah. It has only partially been finished.
