As a solution to declining availability of famland and as an alternative to unsustainable vertical farming, this thesis proposes a new farming practice: hybrid urban vertical farming. It has a high footprint utilization and combines vertical farming with daylight utilization. This is a summary of the research and results.

This research begins with the problem statement: food securtiy is in jeopardy by 2050. By then, there will be 10 billion people on earth while the area of farmland is shrinking. Conventional farming practices use too much space per crop, and thus cannot be scaled up to produce more crops. The alternative that uses farmland more efficiently, vertical farming, is not sustainable enough to be a globally commercially interesting alternative. Therefore, a more sustainable alternative is needed to sustainably grow a lot of food on a small footprint in the years up to and beyond 2050. The proposal is hybrid urban vertical farming: a new farming practice that reuses greenhouse components to build a modular construction in which layered growing systems can be built that can also utilize daylight through the glass greenhouse deck. This way, its sustainability over vertical farming is increased through material reuse and artificial light reduction.

The research continues with an examination of the components that compose greenhouses, and an analysis of how those can be refurbished reused. This was done in close collaboration with companies in the sector. With that knowledge, a case study greenhouse, MightyVine phase 3 from Chicaco, the United States of America, is then analyzed. Using the resulting components, nine modules are designed that together can create any possible module configurations to withstand wind loads. A sliding and rotating growing system is designed for in those modules. Those features contribute, respectively, to an even exposure to daylight for crops in different containers, and to reducing the footprint occupied by workspace. Building modules with reused components results in as much as 45-76% of the carbon footprint being saved. For the growing systems, which reuse midfield columns for their structure, it is 16-18%.

With the design of growing systems completed, it was optimized how far they need to be spaced apart to maximize the use of daylight on a given footprint. This revealed that growing systems must be side-by-side to naturally provide 34% of the light requirements of crops annually. Knowing that, it was also possible to determine the module configuration that reuses the most midfield columns (which is the most reused greenhouse component). That optimal module configuration is eight modules long and four modules deep. This leads to a 95% reuse rate for midfield columns. That module configuration can grow 3.3 times more crops per square meter than the case study greenhouse, and at only 4.5% of the greenhouse’s footprint.

Carbon footprint calculations that consider only the emissions emitted in the production of materials for module construction and growing systems show that hybrid urban vertical farming is less sustainable than greenhouse agriculture: by a factor of 1.63 times. Published research indicates that vertical farming is 2.4 times less sustainable than greenhouse agriculture. So the conclusion of this thesis: a hybrid urban vertical farm truly is a hybrid farming practice. It has a better footprint utilization than greenhouse agriculture has, but it is less sustainable. However, it is more sustainable than vertical farming. So, today, hybrid urban vertical farming is not yet the most sustainable farming practice out there, but when farmland runs out in the years to 2050, then hybrid urban vertical farming will be the more sustainable option over vertical farming. Until then, the concept can be further developed and made more sustainable to be competitive with conventional farming practices sooner if possible.