Except Integrated Sustainability
Except Integrated sustainability.
Flourish in a changing world.
Multi-disciplinary consulting, innovation and development organization working on advanced sustainability projects around the globe.


Project > High Performance Sustainable Polyculture Agriculture

Polydome is a revolutionary approach to greenhouse agriculture that offers the possibility of commercial scale, net-zero-impact food production. The Polydome system strategically interweaves a wide variety of crops and animals, taking advantage of every inch of the greenhouse while eliminating the need for synthetic fertilizers and pesticides.

Polydome is an answer to a part of the world food crisis. With its high yields (60 – 90 kg per square meter), and diverse outputs (over 50 crops, two mushroom varieties, chickens, eggs, fish, and honey), even a small Polydome system can sustainably provide a varied food supply for a large population. Scalable. Profitable.

Polydome has been extensively researched by Except and over 12 partners in the industry. Concept overview and technical details are published in a free open source book, downloadable below.

It is estimated that by using Polydome, even cities as densely populated as New York City could provide the majority of their own food supply using available roof space. A less dense city like Rotterdam could provide an estimated 80% of its food needs using only 3% of its surface area.

How does Polydome work?

Productive ecosystems
Though it uses advanced greenhouse technology, Polydome’s true inventiveness lies in a non-technological strategy: it maximizes food production and variety by operating more like a self-maintaining ecosystem than an industrial farm.

Symbiotic systems
While greenhouses generally produce only one kind of crop, Polydome is a polyculture system with many crops and livestock growing at once. Plants, crops, animals, and insects are strategically interwoven to connect waste, water, and energy flows and capture the benefts of varied space and light conditions. Animals within the system range freely and live naturally, while the design of the crop layout limits the need for repetitive human labor.

Modular system
The main design challenge behind Polydome was the creation of successful “crop clusters,” groups of interacting plants that use space and nutrients to maximum effect. These crop clusters are like interchangeable Lego blocks, with many functional combinations that can be mixed and matched depending on the desired output of the greenhouse and local market demand.

Environmental Benefits
Depending on the mix of crops and animals, Polydome systems can be fully zero-waste. Plant waste is reused as mulch, compost, or fish feed, while animal wastes are processed into plant nutrient supplements. Rather than shading plants using mechanical screens, shade-loving plants are intercropped below plants with a high demand for direct sunlight.

Mushroom cultivation, chickens, and composting provide supplemental CO2 rather than generators or the combustion of fossil fuels. Using temporal and spatial stacking, companion planting, and the layering of soil crops with hydroponically-grown crops, the Polydome design allows for greater production density than in any other cultivation method.

A Community Asset
On a socio-economic level, the model shows that this system is highly profitable. It allows for high-density production, the capture of several high-value niche markets, and savings on technological inputs. Rather than focusing on the large-scale production of a single, relatively valuable crop (tomatoes, peppers), Polydome produces many high value crops that usually have a limited local market (herbs, mushrooms, berries).

Potential for Urban Agriculture
By combining a Polydome system with a shop or restaurant, food can be sold directly to customers. Shrinking the distance between producer and consumer also translates into higher profits. Polydome also provides possibilities for urban agriculture that with traditional systems might not be feasible or desirable.

Polydome is designed to last a minimum of 30 years, largely because it relies on many perennial crops that do not need to be replanted every year. This means that an investment can be made in its physical structure and appearance, ensuring that it provides a positive aesthetic contribution to the built environment.

Sustainable Agriculture
Polydome systems are a step towards truly sustainable agriculture: they produce high quality food efficiently and locally while creating environmental benefits and caring for human and animal welfare. They provide a realistic way of doubling our food production by 2050 while reducing the overall impact of agriculture.

More information

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Reference Projects

Portal to Venlo

Sustainable Greenhouse Industry Area Development (2010)

The Portal to Venlo offers the greenhouse industry in the east of the Netherlands a model to develop a sustainable industry. The project re-imagines an existing greenhouse industry area, currently fragmented, inefficient, dangerous for bicycle tourists that cross the area and in general rather unappealing.

... read more >

Hortus Celestia

Vertical farm & office tower

The Hortus Celestia is a vertical farm tower, designed for Naaldwijk, the Netherlands. The tower rises 28 stories high above the greenhouse-filled landscape, offering 14 farming floors with embedded expo centers.

The tower functions as a demonstration center for innovative Dutch greenhouse industry partners, and attracts international visitors from around the globe.

... read more >

Meat Sector Roadmap

Towards an integrated circular sector

We developed a roadmap of the Dutch meat process sector, production and processing companies and their suppliers, together with DNV. The road map shows opportunities for optimal use of all energy and material flows in the product chain of chicken, pork and beef, and maps their sources. The maps bring insight to all stakeholders involved, and enables decisions on improving entire sections of the production chain at once.

... read more >

Serenity Farms

Sustainable food production in arid regions

Serenity Farms is a concept for a sustainable 110ha greenhouse facility for profitable food production in arid climates. The first site is to be located on the west coast of Saudi Arabia, under the vision of the Reza Investment Company. It will be the largest sustainable greenhouse operation in the world. The only water it uses is salt water sourced from the red sea, and is powered entirely by the sun. The core of Serenity Farms is a high tech food production solution that provides fresh fruits and vegetables for 170.000 people.  

... read more >


Except Integrated Sustainability

Integrated Sustainability

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  • Albertien Perdok

    Ecosystem Designer
  • Anniek van Mierlo

    Except Academy
  • Chris Muglia

    Management Associate
  • Laurina Phillip Muglia

    Social Entrepreneur
  • Michiel van der Vight

    Senior Associate
  • Paula Land

    Project Support