Barriers and Opportunities Regarding the Implementation of Rooftop Eco.Greenhouses (RTEG) in Mediterranean Cities of Europe

Today 50 percent of the world's population lives in cities. This entails an excessive exploitation of natural resources, an increase in pollution, and an increase in the demand for food. One way of reducing the ecological footprint of cities is to introduce agricultural activities to them. In the current food and agriculture model, the fragmentation of the city and the countryside means energy use, CO 2 emissions from transport, and large-scale marketing requirements. Rooftop Eco.Greenhouses (RTEG) consist of a greenhouse connected to a building in terms of energy, water, and CO 2 flows; it is a new model for a sustainable production, an eco-innovative concept for producing high quality vegetables and improving the sustainability of buildings in cities. The main objective of this study is to examine the barriers and opportunities regarding the implementation of RTEG in Mediterranean cities in Europe. The work method consisted of discussion seminars involving an interdisciplinary group of experts in the area of agronomy, architecture, engineering, environmental sciences, industrial ecology, and other related disciplines. The barriers and opportunities of RTEG take into account social, economic, environmental, and technological aspects and were determined and analyzed according to three scenarios of implementation: residential buildings, educational or cultural buildings, and industrial buildings. We would highlight the interconnection of the building and the greenhouse as an opportunity of RTEG, making use of water, energy, and CO 2 flows between both, as well as the decrease in food transportation requirements. The methodology applied to the study was positive due to the interdisciplinary participation of experts which facilitated a global vision of the implementation of the project.