Thammasat University – the largest urban rooftop farm in Asia

largest urban rooftop farm

Bangkok and cities in Southeast Asia are among the most vulnerable to climate impacts in the world. Victims of their own rapid development, unchecked industrialization urbanization on rice-producing societies. Unpredictable extremely wet and dry weather is now the new normal, causing flooding, damaging agriculture, destroying livelihoods, and threatening millions of people. Meanwhile, formerly fertile and productive, agricultural lands across Thailand have been converted into industrialized farms which not only pollute natural ecosystems, but also disregard public health and income equality.

largest urban rooftop farm

But just a short trip away, a new integrative solution at Thammasat University (TU) has emerged to create climate resiliency, demonstrating how development can contribute more solutions than the problems it has created by embracing landscape architecture and past agricultural practices. As the largest urban rooftop farm in Asia, the 22,000 sq. m. (236,806 sq. ft.)  Thammasat University Green Roof tackles climate impacts by incorporating modern landscape architecture with traditional agricultural ingenuity, the green roof, urban farming, solar roof and green public space.

The project combines the elements of ‘architecture’ and ‘landscape architecture’ so seamlessly that it is almost impossible to categorize what type of work it actually is. The form of the building is developed from the H-shaped floor plan, rendering the elevation that resembles a large mountain with a massive green space of garden covering upper part.

By mimicking traditional rice terraces, Thammasat University Urban Farming Green Roof has become an all-in-one solution–as a public green space, urban organic food source, water management system, energy house, and outdoor classroom–which serves as an adaptation model for anticipated climate impacts that can be implemented and developed across Thailand and Southeast Asia.

largest urban rooftop farm



A century ago, the peri-urban of Bangkok, the Rangsit field once filled with paddy fields and swamps, envisioned by King Rama 5 to be the most productive rice-farming area in the world. But after years of unstoppable urban sprawl, the marshlands have turned to paralyzed concrete cities, no longer able to breathe, absorb water, or grow food. To revive the land on which it stands on, Thammasat University, one of Thailand’s leading universities, has created the innovative architecture by transforming an unused rooftop into a solution to climate, food, and pollution crisis.

Inspired by local ingenuity and traditional agricultural practices, the Thammasat University Urban Farming Green Roof’s cascading farm levels form a detention lawn which slows down, absorbs and stores rainwater while using it to grow food. Any runoff is filtered through each layer of soil and later saved up in four retention ponds, which can collect the water up to 11,718 Cubic meters (3,095,570 gallon) for rooftop irrigation and future use

To restore biodiversity back to the swamplands, The native plant strains grown on the farm creates a microclimate and attracts pollinator bird and insect species. As the plants on the Thammasat University Green Roof breathe, the oxygen and moisture they release helps build a stable microclimate for the animals to take refuge.

During heavy rainfalls, abundant soil mass and nutrients can be lost in along with the runoff. But with cascading layers of planters, the plants on the Thammasat University Green Roof hold the soil together and slowdown runoff. By embracing not only the intention of organic, but also regenerative agriculture, it ensures a food source beneficial to both the health of humans and nature.


Although concrete absorbs and reflects most heat, it barely absorbs any water, leaving cities like Bangkok at risk of urban flooding whenever it rains. By incorporating the resourcefulness of farmers on mountainous terrains across Southeast Asia with modern landscape architecture, the Thammasat University Green Roof mimics the form and functions of traditional rice terraces to achieve maximum productivity, collecting and storing rainwater efficiently for times in need.

With each cascading level, the green roof is not only able to absorb rainwater, but also slow down runoff, both for up to 20 times more than a normal concrete rooftop. While controlling stormwater peak rate and volume, this water management system also retains and utilizes runoff efficiently to grow food for the campus. Equipped with four retention ponds at each of its corners, it also significantly reduces the volume of stormwater leaving the site, saving the water it for future use and irrigation during dry spells.

As intensive agriculture expands, monoculture crops continue to scour natural food sources and leave trails of deadly chemical fertilizers and toxic waste behind. Thailand is the world top five world importing pesticides. By cutting chemical pesticide and fertilizer use altogether, the Thammasat University Green Roof offers an organic farming as model for sustainable landscape management to transition from chemical-dependent agriculture for both the sustainable health of people and the environment, as well as the economy.

In addition to preventing runoff pollution from entering drainage systems, and later on rivers, lakes, and oceans, the Green Roof’s vegetable terraces also filters the rainwater–often carrying air pollutants into water bodies–through several layers of plants and soil before it leaves the site and reaches residential water sources and marine ecosystems. The plants, too, help remove harmful pollutants from the atmosphere.



Now filled with numerous skyscrapers and countess of wasted concrete rooftops, Bangkok can simply reach up to 40˚C as concrete soaks up most sunlight and reflect heat to its surrounding. Instead of another wasted rooftop which contributes to urban heat islands, the mountain-shaped Thammasat University Green Roof utilizes its vast space as an infinite source of clean energy, not only in terms of organic food, but also solar power for the community.

Taking advantage of the abundance of sun Thailand receives, the Thammasat University Green Roof harnesses readily-available solar energy at zero production cost and produces 500,000 watts (equivalent to 25,000 electric light) per hour to pump water for irrigation on its urban farm, as well as generate electricity inside the building underneath it. Placed on the South side of the architecture, the solar panels of the Thammasat University Green Roof–covering the total 3,565 sq. m. roof–is exposed to sunlight all day long.

By incorporating this renewable photovoltaic system, the Thammasat University Green Roof not only paves the way from reliance on fossil fuels, but also reduces economic costs. The green roof cools air both inside and outside of the building, reducing greenhouse gas emissions from and spending on energy consumption, primarily from air conditioning. Similarly, it can also improve insulation to retain cooling temperature.



At a time of prolonged periods of erratic weather patterns and extreme seasonal changes, food and water scarcity poses one of the biggest threats to human civilization. As, the reality that 80% of the world’s populations will live in cities by 2050. City space need to be more efficient and food production need to be more sustain to human health and the world.

By utilizing traditional ingenuity from rice farmers on the sloped hill and mountain terrains across Southeast Asia, the Thammasat University Green Roof can grow up to approximate 135,000 rice meals each year to feed the community.

While the urban rooftop farm holds the key to Thammasat University Green Roof’s functions, the green canteen completes its intended purpose of creating a truly holistic and sustainable model for business and conservation. By building both the organic food source and destination in close proximity, the system is able to reduce emissions and waste–produced during production, processing, packaging, transportation, and disposal–from start to finish.

Growing a variety of indigenous plant species and a naturally-bred strain of rice tolerant to floods and droughts, the Thammasat University Green Roof serves produce fresh from the farm roof to the table. Any food leftover from the plate and the kitchen–once edible food is distributed to the local community–is composted and sent back to feed the farm as organic fertilizer to grow nutritious crops for the next harvest.

By creating a localized food supply chain that produces all-organic vegetables, the Thammasat University Green Roof’s urban farm and organic canteen is able to reduce both emissions and pollution from its production, consumption and disposal by cutting chemical use, energy consumption, and food waste while encouraging a low-impact plant-based diet.



To help damaged ecosystems, contaminated food sources, and undercompensated farmers recover from the aftermath of industrialized agriculture–a system which shifted power from local manpower to machinery and foreign imports–the Thammasat University Green Roof creates employment for students and staff inside and surrounding the campus, while giving them the opportunity to contribute to feeding the community and conserving the ecosystem through sustainable agricultural practices.

By establishing a functioning and self-sustaining farming model which puts the human well-being and ecological health at core, the Thammasat University Green Roof is redefining the operations of Thailand’s agricultural sector. By making food production profitable again for small-scale farms and creating employment and businesses opportunities to grassroots farmers, and redistributing land and food sovereignty from monopolies and middlemen to create more income equality. Similarly, by reshaping agricultural work, one of the Thammasat University Green Roof’s objectives is to diffuse economic power in urban Bangkok and other major cities, and spread development evenly across the country’s geography.


The Thammasat Green Roof serves as another landmark for the university’s commitment to bringing urgency to climate issues. In order to equip visitors with the knowledge for real-world application–on how to grow food, especially to prepare for climate uncertainties with available resources–offers not only information about the green roof’s features but also year-round workshops on sustainable agriculture and urban farming for 40,000 members of the university campus to take home.

Built in Thammasat University, a member of the Sustainable Universities Network, the Thammasat Green Roof serves as another landmark for the university’s commitment to bringing urgency to climate issues. In order to equip visitors with the knowledge for real-world application–on how to grow food, especially to prepare for climate uncertainties with available resources–offers not only information about the green roof’s features but also year-round workshops on sustainable agriculture and urban farming for 40,000 members of the university campus to take home. Green Roof holds incredible potential in the replicability of its current blueprint, as well as possibilities for improvement and modification to suit other cities struggling with climate impacts across the world.

To wholly fulfill its role as part of an academic institution, the Thammasat University Green Roof is also committed to serve as an outdoor classroom for students, faculty, staff and visitors can understand more about climate resilience and climate justice while also learning it into application, with activities all year-round based on the farming calendar that provide inclusive learning about permaculture, nutrition, and other topics.

The Thammasat University Green Roof also serves as a platform for outdoor learning and social interaction across various disciplines within campus. By gathering and connecting students and faculty of areas related and unrelated to environmental conservation or sustainable development, the public space allows room for exchange of knowledge and ideas on climate action and adaptation with a holistic approach between Thailand’s future leaders.


With this integrative approach, the Thammasat Green Roof aims to educate the community of the impacts, causes, and solutions of climate change–which is an umbrella to both the ecological and human rights lens of the food, energy, and waste industry, as well as water management, financial economy, and governance–to ground them with information to reflect on their personal carbon footprint and share their newfound knowledge with their social networks.

This holistic solution was all inspired by the local ingenuity, carried on by several generations of farmers who learned from the land and water they lived with. To show our young leaders how to welcome challenges of the uncertain future, past knowledge about the origins of their culture and native soil have been embedded in the Thammasat University Green Roof as lessons for them to adapt and take steps forward.

Thammasat University, Rangsit Campus

Location | Bangkok, Thailand

Building Type |  Multi-Purpose Building with the Biggest Urban Farming Green Roof in Asia

Project Owner | Thammasat University

Landscape Designer and greenroof design | LANDPROCESS (Kotchakorn Voraakhom)     

Architect | Arsom Silp Institute Of The Arts
Structural Engineer | Degree System Co., Ltd
System Engineer | TPM Consultants Co., Ltd
Contractor | CM49

Project Information
Green Roof Area: 22,000 sq. m. (236,806 sq. ft)
Urban Farming Area: 7,000 sq. m. (75,300 sq. ft) 32%
Solar Roof Area 3,565 sq. m. (38,373 sq. ft.) 16%
Public Space Area 7,000 sq. m. (75,300 sq. ft.) 32%
Service and Utility 4,435 sq. m. (47,738 sq. ft.) 20%
Building Area: 60,000 sq. m (645,840 sq. ft.)

Images & Diagrams | Courtesy of LANDPROCESS

About Damian Holmes 3313 Articles
Damian Holmes is the Founder and Editor of World Landscape Architecture (WLA). He is a registered landscape architect (AILA) working in international design practice in Australia. Damian founded WLA in 2007 to provide a website for landscape architects written by landscape architects. Connect on Linkedin at