A combination of LCC and ecosystem services assessment making use of system dynamics modelling

Oral Presentation Abstract: In the construction sector, traditional life cycle costing (LCC) is a well-known and robust approach useful to compare the total internal cost of (natural or grey) infrastructure alternatives from their design until their end of life. Two other types of LCC exist:environmental and social . The former, usually applied in combination with LCA, monetarise the cost of environmental externalities and the latterintegrates social externalities. However, it is difficult to take into account positive environmental and/or social externalities only making use of these methods. The combination of LCC with ecosystem services (i.e. the benefits that people obtain from natural elements) could facilitate to account negative and positive environmental and social externalities of solutions such as urban forests, green roofs/walls, or constructed wetlands. Since externalities of natural solutions are changing along time due to the interaction of factors, their valuation also requires use of techniques such as system dynamics models. In this research, we present a methodology that integrates social LCC with ecosystem services assessment, supported on a system dynamics model. This type of methodological integration would be useful for cost-benefit analysis of natural infrastructures where externalities should be considered. The methodology is applied to a pilot case study (a green roof), taking into account three types of costs (investment, operational, and deployment) for an expected operational life of 50 years. The application show the potentiality of blending LCC with ecosystem services assessment and system dynamics for cost-benefit analysis done under a sustainability perspective.