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Illustrates how Life Cycle Management is or can be integrated into business practice, thereby creating sustainability within organizations.

The ICTA-ICP Rooftop Greenhouse Lab (RTG-Lab) is a research-oriented RTG situated in the UAB Campus (Bellaterra, Barcelona). In contrast to current RTGs, the RTG-Lab integrates energy, water and CO2 flows into the building’s metabolism. This integrated RTG (i-RTG) is an eco-innovative concept that will enhance the sustainability of both systems involved while producing high-value crops and maintaining indoor comfort in buildings with lower energy inputs. The RTG-Lab, within the Fertilecity project, aims to demonstrate the feasibility of producing vegetables in i-RTGs in the Mediterranean context and to quantify the environmental and economic performance of the metabolic integration between the greenhouse and the building. To do that, experimental crops (lettuce and tomato) in soil-less culture systems (perlite) will start on Fall 2014. Preliminary data of the metabolic integration is described in this contribution. First, the residual heat from the building will be introduced in the greenhouse to maintain crop temperatures. Moreover, the airflow from the building will help the ventilation of the greenhouse in hot episodes. Second, the rainwater collected in the rooftop of the building will be used for the irrigation of the crop, leading into a 100% water self-sufficient crop. Third, the airflow from the building has a higher CO2 concentration than the greenhouse air. This CO2 will be used by the crop when supplied to the greenhouse, as in current CO2-injection techniques in industrial horticulture.

El diseño de ciudades sostenibles se perfila como la mejor solución para hacer frente a los problemas ambientales globales que ha creado nuestra sociedad. Para ello, se requieren nuevos enfoques e instrumentos con los que mejorar el diseño y la planificación urbanísticos. Dadas las circunstancias, el ecodiseño surge como una de las herramientas esenciales para avanzar hacia unas ciudades más sotenibles. En este artículo presentamos tres estudios de caso de aplicación del ecodiseño en Barcelona: una farola, un punto limpio de barrio y un barrio entero.

The Kyoto protocol, signed by 160 countries, pledges greenhouse gas (GHG) emissions reductions of at least 5% relative to 1990 levels [1]. Besides the global concern and action to mitigate GHG emissions, national-level policies are increasingly being supplemented with city-scale actions to mitigate climate change [2]. Marshall [3] makes us notice that although much attention on mitigating climate change has focused on alternative fuels, energy consumption in vehicles, and electricity generation, better urban design represents an important yet undervalued opportunity. The built environment is responsible for huge amounts of pollution and waste generation [4] at millions of different locations worldwide. And one of the major construction materials is concrete.

Urban rooftop farming favours local food production. Although rooftop farming is perceived as 33 a sustainable system, there is a lack of quantitative studies on rooftop farming. There we set up 34 experiments in the community rooftop garden of a public housing building in Bologna, Italy, 35 between 2012 and 2014. We grew lettuce, a leafy vegetable, using three techniques: nutrient 36 film, floating hydroponic and soil cultivation. We also grew tomato, chilli pepper, eggplant, 37 melon, watermelon on soils. Data was analysed by life cycle assessment for environmental and 38 economic performance. Results reveal that the best techniques of lettuce cultivation to address 39 global warming were floating in the summer, with 65-85% less environmental impact per kg 40 than nutrient film; and soil production in the winter, with 85-95% less environmental impact. 41 Furthermore, floating production was 25% cheaper in summer and soil was 65% cheaper in 42 winter, compared to the nutrient film technique. For soil production, eggplants and tomatoes 43 showed the best environmental performances of about 74 g CO2 per kg. Eggplant production in 44 soil gave in the cheapest crop of 0.13 € per kg.

Purpose: rooftop greenhouses (RTGs) are increasing as a new form of urban agriculture. Several environmental, economic, and social benefits have been attributed to the implementation of RTGs. However, the environmental burdens and economic costs of adapting greenhouse structures to the current building legislation were pointed out as a limitation of these systems in the literature. In this sense, this paper aims to analyse the environmental and economic performance of RTGs in Barcelona. - Methods: a real RTG project is here analysed and compared to an industrial greenhouse system (i.e. multi-tunnel), from a life cycle perspective. Life cycle assessment (LCA) and life cycle costing (LCC) methods are followed in the assessment. The analysis is divided into three parts that progressively expand the system boundaries: greenhouse structure (cradle-to-grave), at the production point (cradle-to-farm gate), and at the consumption point (cradle-to-consumer). The applied LCIA methods are the ReCiPe (hierarchical, midpoint) and the cumulative energy demand. A cost-benefit analysis (CBA) approach is considered in the LCC. For the horticultural activity, a crop yield of 25 kg · m−2 is assumed for the RTG reference scenario. However, sensitivity analyses regarding the crop yield are performed during the whole assessment. - Results and discussion: the greenhouse structure of an RTG has an environmental impact between 17 and 75 % higher and an economic cost 2.8 times higher than a multi-tunnel greenhouse. For the reference scenario (yield 25 kg · m¯²), 1 kg of tomato produced in an RTG at the production point has a lower environmental impact (10-19 %) but a higher economic cost (24 %) than in a multi-tunnel system. At the consumption point, environmental savings are up to 42 % for local RTGs tomatoes, which are also 21 % cheaper than conventional tomatoes from multi-tunnel greenhouses in Almeria. However, the sensitivity assessment shows that the crop efficiency is determinant. Low yields can produce impacting and expensive vegetables, although integrated RTGs, which can take advantage from the residual energy from the building, can lead to low impacting and cheap local food products. -Conclusions: RTGs face law limitations that make the greenhouse structure less environmentally friendly and less economically competitive than current industrial greenhouses. However, as horticultural systems and local production systems, RTGs can become an environmentally friendly option to further develop urban agriculture. Besides, attention is paid to the crop yield and, thus, further developments on integrated RTGs and their potential increase in crop yields (i.e. exchange of heat and CO2 with the building) are of great interest.