Green rooftop systems: a South African perspective

Abstract

The purpose of this study is to determine the outcome of green rooftop systems in South Africa. Cities in South Africa are expanding with new developments. With development and expansion comes the increase in pollutants, undesirable living conditions and challenges to overcome. Rooftop gardens are not getting the recognition for the value of it to the environment, the citizens, the industry and the buildings as such in South Africa. This is due to lack of knowledge and innovation. Green rooftop systems is a relatively new concept in South Africa. The study used a literature review followed by field notes and 68 questionnaires received back from contractors, quantity surveyors, engineers, architects and citizens of Johannesburg. The respondents do not have experience regarding the construction of green rooftop systems, and thus indicates why professional members of the construction industry do not recommend the development thereof. This further indicates that there is a lack of knowledge in the industry regarding the construction of green rooftop systems and the benefits that accompanies green rooftop systems. Despite the lack of knowledge in the industry, the materials needed to construct green rooftop systems are available in South Africa. Johannesburg seems to benefit most from improved air quality and better insulated buildings. Other benefits also includes job creation, aesthetics, eliminating the heat island effect, stormwater management and economic growth. Respondents do not utilise existing green areas due to crime and unsafeness and green rooftop systems provide a secure and safe green area. Green areas also provide health benefits such as promotion of health, reducing stress, depression and anxiety. Drainage and structural integrity seems to be important factors that may limit the development of green rooftop systems due to the financial impact. Incentives seem to be the best way to encourage the development of green rooftop systems according to the respondents. Therefore finance is a concern for the development of green rooftop systems in South Africa; however, there is a demand for it as the respondents are willing to pay more rent for property with green areas. Property value thus increases with the development of green rooftop systems and absorbs the financial impact thereof. There are different types of green rooftop systems with different cost implications and according to the respondents, the semi-intensive green rooftop system will be feasible for South African circumstances. The field notes presented that the few existing green rooftop systems in Johannesburg are semi-intensive green rooftop systems. Green rooftop systems may conserve indigenous plant species and create habitats. In conclusion, Johannesburg will benefit from green rooftop systems, despite the capital cost. The professionals in the construction industry do not have experience in the construction of green rooftop systems and have a lack of knowledge thereof, thus do not recommend the development of green rooftop systems to developers. The lack of knowledge regarding the construction of green rooftop systems and the benefits provided by green rooftop systems should be addressed, not only the construction industry, but also to the public.