Comparative analysis of flat roof systems using life cycle assessment methodology: Application to healthcare buildings

Environmental impact reduction, structural security, and material resource optimization are basic aspects in selecting a construction system. In this study the environmental impact of the 10 predominant flat roof systems in the Spanish infrastructure was evaluated. For this purpose, the systems were subjected to life-cycle assessment, and a single-score damage category analysis was carried out for the midpoint and endpoint stages using the ReCiPe 2016 method, the Ecoinvent 3.5 environmental database, the LCA software SimaPro 9.0 and the “cradle-to-grave” perspective. The cost and installation time per functional unit were also taken into account. Results show that trafficable flat roof systems with fixed deck obtained the highest scores in all dimensions analyzed, with impacts in the range 19.15 pt/m²–22.59 pt/m². Moreover, it was determined that the non-trafficable flat green roof systems have lower cost and labour time values, as well as higher environmental impact values. It was concluded that the non-trafficable roof system with gravel finish and PVC membrane is the optimal solution. This roof typology presents the most favorable results in 20 of 22 impact categories and in the three areas of damage, obtaining the global environmental impact values (7.68 pt/m²), as well as acceptable values in the dimensions of cost (US$66.4/m²) and installation time (1.69 h/m²). Generated knowledge will provide engineering managers with a more detailed perspective of the environmental impact of healthcare infrastructures, increasing the socioeconomic and environmental benefits.