A Comprehensive Review of the Empirical and Nonempirical Literature on Green Roofs

Green roofs (GRs) are one of the best practices that researchers are promoting due to environmental, social, economic, and ecological benefits. This bibliometric review on GRs performs a comprehensive evaluation where shortlisted studies are categorized into empirical and nonempirical. A review of the nonempirical studies affirms the importance of GRs, and the appraisal of the empirical studies helps understand the performance evaluation methods. The performance of GRs largely depends on the overall assembly configuration, especially the vegetation and substrate layers, along with the site and settings. Such studies are conducted through field and laboratory experiments, simulation modeling, mathematical models, or combination methods. These methods help understand the thermal, hydrological and energy performance, urban heat island (UHI) mitigation, noise reduction, air pollution reduction, sustainability, and retrofitting potentials of GRs. This paper presents a comprehensive review of the performance evaluation methods to understand their association with performance parameters and variables. This will help identify an effective performance evaluation method for an inclusive evaluation of any GR assembly.