Sustainable design of vertical greenery systems: a comprehensive framework

The greening of buildings facades is not a new practice; it has been used since ancient times for protection and aesthetic purposes. Nowadays, the approach used towards the greening of facades has changed considerably. Vertical greenery systems (VGS) have been proposed as one of the innovative solutions to promote sustainable building functions. Present-day facade greenery not only offers traditional architectural potential but also incorporates advanced materials and technologies to adapt to the requirements of modern urban life. In recent years, the number of buildings that use this technology has increased considerably, and accordingly, the technology involved and the methods of application have changed to be in line with the new necessities. Various types of VGS have been introduced to provide users with a wider range of options that are applicable in different climates and conditions. As a result, different methods of VGS implementation have been adopted; however, there is no established standardization for VGS designs or their variations. Choosing the proper type of VGS is a crucial step in the decision-making process for VGS design. In this research, we provide an overview of the most significant existing classifications of vertical greenery systems and propose a comprehensive classification based on an analysis of their features and classification criteria. Moreover, influential factors in VGS design are investigated. This article presents a comprehensive framework for the sustainable design of vertical greenery systems by outlining the primary parameters that are crucial to identifying and selecting the most suitable type of VGS. The framework also incorporates design aspects, thus stressing the necessity of considering changes to attributes that could affect the overall functionality of a VGS and, as a result, impact the decision-making process. The results of this study provide a valuable resource to systematically study greenery systems, and their parameters, and also to make informed decisions that are aligned with current the sustainability objectives of future research in terms of cost, energy consumption, and maintenance.