Talking large-scale farming from an entrepreneurial point of view, Lufa Farms in Montreal is pretty interesting.
On top of a two-story building the farm has built a 31,000-square-foot greenhouse. Over 40 different crops are being produced year round in the rather innovative greenhouses that can even stand the snow in the Canadian winters. For watering the plants the farm uses the irrigation system of the building. For some crops produces in this greenhouses, extra energy is needed. This energy is largely provided by the building too. This way Lufa Farms really uses the advantages of the urban conditions, which makes it a real urban rooftop farm. Lufa Farms is currently looking to expand its activities to the United States and find a way to scale urban farming.