By combining hydroponic cultivation , where no soil is needed, with a greenhouse built on existing roofs, Canadian Lufa Farms wants to mass-produce really locally grown food . The latest of the company's roof greenhouses is a full 15,000 square meters. Together with the company's previous three greenhouses, it will be able to supply two percent of Montreal's population with over 100 different types of vegetables and fruits.
One of the advantages of building a greenhouse on a roof is that it is possible to take advantage of the waste heat from the rest of the house. In this way, it is possible to grow even in winter in northern climates without it becoming too expensive and environmentally unfriendly.
Lufa Farm's greenhouse also uses rainwater to a large extent for irrigation. In this way, the need for tap water is reduced by 90 percent according to the company. Then, of course, it is a great advantage that the greenhouses can be so centrally located that the transport distance to the customers is about a few kilometers instead of tens or hundreds of miles.