If you can do it in Montreal, you can do it anywhere. That’s the theory of Lufa Farms, which is growing tender sheaves of lettuce in its 31,000-square-foot greenhouse atop a Montreal office building where winter temperatures rarely rise above freezing.

Lufa’s greenhouse at 1440 Antonio Barbeau supplies more than 25 varieties of vegetables without artificial pesticides, fungicides, or herbicides in its urban greenhouse. Beyond their agricultural prowess, they appear to have handle on the business as well: Lufa reports breaking even this year, and is planning to develop new rooftop greenhouses in Boston, New York, and Chicago. Ultimately, their vision is a city of rooftop farms.

The urban farm is more complicated than your average greenhouse.

The urban farm is more complicated than your average greenhouse: Structures must withstand piles of snow, meet stringent building codes, and offer multiple growing environments for different produce. Yet, in a way, these urban greenhouses are the next evolution of other efforts to make agriculture a year-round artificial activity regardless of the conditions. In the Netherlands, a cold overcast country during the winter, growers use combined heat and energy power plants to supply electricity, warmth, and CO2 to their crops. Similarly, in Montreal Lufa exploits high-efficiency heating systems, automatic energy-saving curtains, and insulation of heated buildings below to make its greenhouses economical. The firm figures it uses half the energy to grow the same amount of crops as traditional growers.

Now it’s time to scale–and turn a profit. No one, it seems, has yet come up with a replicable business model that can scale commercial urban agriculture. Lufa hopes to be the first.

Building urban greenhouses atop some of the world’s most expensive real estate will indeed be something new under the sun. So if you have a roof–at least 40,000 square feet–Lufa is looking for you: inquiries here.