Participating in the construction of the largest earthen city in the world is a dream for any earthen construction expert.
At Arquitectura de Terra we have been working on this large project since 2020, when the Boston Consulting Group hired us as earthen architecture construction consultants for DGDA, the public agency that manages the Diriyah Gate megaproject, a 7 km2 extension of the city of Riyadh built with Adobe erthen bricks dried in the sun. We accompanied the feasibility studies and the realization of the pilot buildings, and now we finally are in the Adobe bricks production phase, to begin construction in 2023
A GIGAproject to extend the city with traditional materials
Riyadh is the capital of a country, Saudi Arabia, which not only has the largest Arab economy in the world, but is also a member state of the G20. It is an economic powerhouse in the region, and one with untethered ambitions.
The crown prince of Saudi Arabia, Mohammed bin Salman bin Abdulaziz Al Saud, has declared that he intends to transform Riyadh into one of the ten most important economic cities in the world. To get there, plans are being drawn up for the kingdom to spend $220 billion to transform the city and double its resident population from the current figure of about seven million people over the next decade, with the construction of mega-projects.
At-Turaif, a UNESCO World Heritage Site built with earth
One of them is the US$50.6 billion mixed-use development in Diriyah, on the outskirts of Riyadh, where the UNESCO World Heritage site At-Turaif is located. This beautiful site built 300 years ago with adobe earthen bricks, was the former capital of the Emirate of Diriyah and also the home of the royal family.
The Diriyah project was first announced in 2017 and the current development is spread over 14 square kilometers. It is being developed in three phases: Diriyah Gate 1 (DG1), Diriyah Gate 2 (DG2) and Diriyah Gate 3 (DG3).
Work is currently underway on DG1, the north side of which is being built with a focus on Saudi culture and heritage and will feature 1,600 residential buildings that will accommodate up to 6,000 residents. All residential, hospitality and cultural buildings being built in DG1 will adhere to the Najdi traditional architectural style, with adobe bricks and adobe plasters.
1,000,000 adobes have already been made for the project: it will be the largest adobe city in the world, designed using traditional construction methods and materials wherever possible.
Diriyah is forecast to host 27 million visitors annually by 2030. To meet those numbers, its hospitality offering will be key: there will be a total of 38 hotels across the project, including names from around the world, from Baccarat Hotels & Resorts of New York to Armani Hotel and Ritz-Carlton.
More than 30 design offices are working on the project: Aedas, Killa Design, OBMI, Rockwell, Oppenheim Architecture and Denniston, among others.
One of the first hotel complexes to open this year is not a hotel, but the 15,000-square-meter Bujairi Terrace dining district, which aims to attract seven million visitors with Michelin-starred restaurants.
THE Diriyah masterplan
Nicknamed ‘The Big Dig’, a 30 meter deep hole is being dug in Diriyah with more than seven million cubic meters of earth dug up in the process. All means of transport and infrastructure (metro lines, roads, tunnels and parking spaces) are strictly underground within Diriyah, which is conceived as a surface area exclusively dedicated to pedestrians.
The excavated soil is taken to a nearby site where it is processed and about 40 percent is reused as fill for the site itself. A part of the remaining land is sent to other construction projects around Riyadh.
The economic and social impact
Most of the ownership of the buildings will be public. Diriyah makes sure that the benefits of the project are felt first and foremost within the kingdom. “As one of the first projects of the kingdom’s Vision 2030 commitment to increase the contribution of tourism to the country’s GDP from 3% to 10%, success will be achieved once Diriyah adds around USD 7.2 billion to the kingdom’s GDP. , create 55,000 jobs and attract more than 27 million visitors a year,” says Inzerillo, general director of the public agency that manages the megaproject, DGDA.
About 85 % of the staff working for the DGDA are Saudi nationals, and a process is underway to ensure that women are well represented within the workforce, with 36% of staff being made up of women and 16% of them in managerial positions.
Earth, a material of the future
That a country oriented to the future like Saudi Arabia invests in earthn architecture is a very strong message for the large economies of the planet: the ecological transition undergoes a paradigm shift at the level of construction materials, and earthen architecture heritage is there to provide valuable lessons of well-being and sustainable development. We are delighted to work in this direction.