Urban Underground Farming

How underground can help increase the scalability and sustainability of urban farming.

Why Farming Below Cities

More than half of the world’s population lives in cities, which means the majority of food consumption happens within urban environments. 

There is an inherent dysfunction in the current food production chain associated with that: food miles. It is estimated that a meal in the United States travels on average 1,500 miles to get from farm to plate. 

There are a few issues tied to food miles: 

  • Transporting food generates CO2 emissions. It is worth to note, however, that CO2 emissions are not the main problem related to food transportation. In fact, transportation accounts for less than 10% of total emissions from food production.
  • Due to the perishable nature of food, chemicals are used to help withstand the travel period. Without them, food would go to waste before even reaching the shelves. These chemicals all end up inside of our bodies.
  • Transportation emits harmful particles into the air, contributing to increasing the already alarming rate of air pollution. 

By taking production near consumption, urban farming annihilates the problems that come with food miles.

As a plus, leveraging unused space in cities for agriculture means that less land needs to be cleared for it somewhere else.

There is also a lot that could be said about how the practice increases the food security, stability and independence of cities that practice it.

How Underground Farming Makes It Possible

The problem with urban farming is that, according to this research paper which estimates, using satellite data, how much food can be grown within cities, urban farming can only supply less than 5% of the total requirement using current technologies. The main culprit? Lack of space.

Underground farming allows to leverage space below cities that would otherwise be unused. Farms can be installed under new buildings, integrating agricultural expansion with urban development.

Potential Impact

Every time new high-rise buildings are built within cities, underground farms can be constructed underneath, which can grow the food needed by its residents and nearby restaurants. 

We built models where GreenForges would be used in urban projects to grow 700 lbs (317kg) of fresh and pesticide-free fruits and vegetables per inhabitant yearly, which is nearly double the amount of minimum fruits and vegetables intake recommended by the WHO.

Growing food within cities can have large positive impacts on both the population and the environment, let’s review some of them: 


The rise of urban underground farms would create new jobs and entrepreneurial opportunities, unlocking access to an industry that is otherwise not especially attractive due to its ties with land ownership and hard labor. 


Because food grown in underground farms is pesticide-free, it’s easy to picture the benefits deriving from large-scale adoption of urban agriculture. Would you rather feed your kid a chemical-free piece of vegetable that was picked the same morning from the farm or a head of lettuce that has been traveling for days to get to your plate filled with chemicals? 


CO2 emissions are being generated by the food transportation and the associated consumption of fossil fuels. Bringing production near consumption signifies cutting those negative effects out of the equation almost entirely. 

In addition, underground farms can act as carbon sinks within the city, helping to offset some of its CO2 emissions. 


If part of the production of fruits and vegetables is transferred inside urban environments, some land that was dedicated to agriculture can now be left alone for nature to take it back. 

Agriculture has already claimed one-third of the world’s habitable land, posing a hefty threat to wildlife diversity as lots of their habitats are now unlivable. 

The danger that comes with diversity loss in both flora and fauna is out of the scope of this article, but regenerating the ecosystems where different biomes used to thrive is a priority. 

Although not regenerative per se, urban underground farming leverages spaces that are already taken by human development, not claiming any new ones for food production. 

Moreover, if part of the production of fruits and vegetables is transferred inside urban environments, some land that was dedicated to agriculture can now be left alone for nature to take it back. 

Case Study - The Waterproof Building

3D rendering of the Waterproof building


Back in September 2020, GreenForges was approached by two students, Aafke Goetheer and Fei Duindam, from the Hotel Management School Maastricht to integrate our systems into a concept for a future building of 2050.

The project was built to take part in the Sustainable Hospitality Challenge, a yearly competition where students from top-tier international hotel schools challenge each other by coming up with innovative solutions for real-life industry cases.

This year's theme interested the context of future cities. What will hospitality look like in 2050? 

The Waterproof concept won the semi-finals and will participate in the finals, in Dubai, on September 20th, 2021.

The Concept

The vision behind the concept was to create a world in which the basic needs of humankind will be fulfilled without neglecting the needs of the earth itself.

The Waterproof building revolves around a key element of life: water. Water is explored in its three phases — solid, liquid and gas — each inspiring specific features of the building itself.

GreenForges Integration

We estimated a need of around 700lbs of fruits and/or vegetables per person, per year. Here are our estimates on how to get there:

Economic Estimations

Number of GreenForges 40
Depth of each GreenForge 100ft (30.4m)
Farm size 6086 ft (565.4 sq.m)
Construction cost $3,704,143 (USD)
Facility annual expenses $1,343,760 (USD)
Investment needed $3,972,634 (USD) *Includes construction costs + one year of labor expenses
Facility annual revenue $3,592,030 (USD)
Facility annual gross profit with loan paid off $2,248,269 (USD)

Please note that these predictions do not take into account inflation or risks tied to supply chains, so take them with a grain of salt. It’s also possible the technology will be significantly more advanced by then, allowing for cost reductions.

The main point that can be extrapolated from this scenario is that food production can be an active part of hospitality and real estate development. Underground farming provides the means for embedding farms within the foundations of the buildings themselves, without sacrificing precious surface space somewhere else.


There are still challenges associated with implementing underground farming technology in buildings.

For example: 

  • Farms cannot be installed under existing buildings, only in new developments.
  • The exterior casings need to be replaced every 80-100 years
  • Inputs needing to be transported to the basement is not ideal for workflow
  • More similar challenges

An alternative to some of these restrictions is building deep and high output underground farms on the outskirts of the city. Although the underground farms would lose the benefits of integration with the building above, they would still be useful in producing locally-grown fresh food all year round.


Given the right conditions, underground farms can become a crucial food production asset for the cities of the future. The technology could bring food security and autonomy to rapidly expanding urban settings all the while creating economic opportunities for its inhabitants and allowing for regeneration of rural land.