Abstract
At present, the world is facing many hurdles due to the adverse effects of climate change and rapid urbanization. A lot of rural lands and villages are merged into cities by citizens, resulting in high carbon emission, especially in the built environment. Besides, the buildings and the construction sector are responsible for high levels of raw material consumption and around 40% of energy- and process-related emissions. Consequently, the interest in defining the carbon footprint of buildings and their components is on the rise. This study assesses the carbon footprint of a green roof in comparison to a conventional roof in a tropical climate with the aim of examining the potential carbon emission reduction by a green roof during its life cycle. A comparative case study analysis was carried out between an intensive green roof and a concrete flat roof located on two recently constructed commercial buildings in the Colombo district of Sri Lanka. Data were collected from interviews, project documents and past literature in addition to on-site data measurements and a comparison of life cycle carbon emissions of the two roof types was carried out. The results revealed that the operational phase has the highest contribution to the carbon footprint of both roof types. In the operational phase, the green roof was found to significantly reduce heat transfer by nearly 90% compared to the concrete flat roof and thereby contributed to an annual operational energy saving of 135.51 kWh/m2. The results further revealed that the life cycle carbon emissions of the intensive green roof are 84.71% lower compared to the conventional concrete flat roof. Hence, this study concludes that the use of green roofs is a suitable alternative for tropical cities for improving the green environment with substantial potential for carbon emission reduction throughout the life cycle of a building.
Highlights
Rapid urbanization processes have resulted in many rural lands and villages being transformed into cities, in developing countries around the world
The results further revealed that the life cycle carbon emissions of the intensive green roof are 84.71% lower compared to the conventional concrete flat roof
This study focused on a comparative analysis of life cycle carbon emissions of an intensive green roof and a conventional concrete flat roof
Summary
Rapid urbanization processes have resulted in many rural lands and villages being transformed into cities, in developing countries around the world. This inadvertently has led to the damaging of green spaces and numerous other problems due to the non-sustainable and inefficient use of urban systems, including carbon emissions [1]. 90% of this increase is happening in Asia and Africa [2]. With these increments, Sri Lanka, as an Asian country, will have to face several environmental devastations and issues including the high emission of carbon in the building sector. The buildings and construction sector consumes around 40% of global raw materials and contributes to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
