Green Roofs’ End of Life: A Literature Review

Abstract

Green roofs are increasingly being used in urban settings because of the many benefits they are capable of providing. Because of their widespread use, the issue of how to conduct proper disposal of green roofs once they have reached their end of life is beginning to be raised. The present study is a review of the scientific literature published between 2007 and 2022. Specifically, the contribution of this review study is to clarify whether a waste scenario exists and if so, identify the methodological frameworks and/or criteria used in green roof-related studies to establish the end-of-life scenario of a given green roof, which will then be used to analyze its environmental and economic performance. The literature analysis indicated that a standardized method, widely adopted, which allows identifying recovery and/or disposal treatments to be assigned to waste from the disposal of a green roof, is missing. In general, the feeling one gets from reading all these articles is that when it comes to the end of life of green roofs, everything is rather vague, and that one proceeds in no particular order. The main results of the study are a collection of the criteria currently proposed in the literature to identify the end-of-life scenario of green roofs. These essentially include predominant waste management practices in place in the country where the green roof is located, safety sheets of products constituting single layers of the green roof, and statistical data on the management of specific types of waste. The results also include an overview of the current body of knowledge related to the management of the end-of-life of these building components. This study also intends to serve as a starting point for opening a debate on the disposal of green roofs, a current hot topic and still open as it has not yet been codified. Finally, some recommendations for future research work in this field are proposed.