An Investigation of Green Roof Spatial Distribution and Incentive Policies Using Green Buildings as a Benchmark

Abstract

The global spread of green roofs is becoming increasingly important in the context of increasing urbanization and climate change as they provide multiple benefits, including urban heat island effect (UHI) mitigation, stormwater retention and urban flood risk reduction. However, current research provides little insight into how green roofs are used and promoted globally. Therefore, it is essential to look at the global spatial distribution of green roofs and the related policies by using green buildings which have been successfully promoted as a benchmark. This study collected data from multiple sources, such as a dataset of spatial distribution of green roofs from eight countries, and 124 green roof incentive policy texts from 88 cities. Spatial analysis was conducted using ArcGIS Pro, and different types of incentive policies were explored using word frequency analysis. The results show that (1) the unbalanced distribution of green roofs in cities is prominent, with significant regional differences and clustering characteristics along water systems; (2) in the vast majority of countries, the types of incentive policies for green roofs lack diversity; (3) green roofs lack a well-developed rating system compared to how green buildings are promoted. Combining green buildings with green roofs and exploring the gaps between them, this study will help further explore the application of green roofs worldwide and guide governments or non-governmental organizations to develop and implement more efficient policies and provide recommendations to promote the popularity of green roofs worldwide.