Green Roof Concepts as a Passive Cooling Approach in Tropical Climate- An Overview

Abstract

Abstract. Nowadays, increasing of energy consumption due to global warming issues such as heat island effects has attracted the awareness of researchers, architects, engineers, property developers, and authorities to the crucial of green construction or sustainable development concept. Energy efficiency has been identified as a key consideration in discussions of this concept. In term of energy, Malaysia ranked 33 rd in the list of global electricity consumption and 25 th in the list of man-made carbon dioxide emissions. If energy consumption continues to increase at its current rate, domestic petroleum reserve in Peninsular Malaysia is predicted to be depleted by 2014 and Sarawak by 2020 [1]. As responding to the increasing of energy consumption, the demand of green roof technology as passive cooling technique has been recognized worldwide. Generally, by greening the rooftops in urban area, the impact on the urban climate and microclimate as well as on the indoor climate of buildings beneath them will be reduced. Therefore, this paper systematically review the concepts of green roof to give a basic understanding as global. Discussion on the benefits of this concept and its components among topic will be discussed.

Review of Significant Maintenance Criteria for Tropical Green Roofs in Malaysia

“…A green roof is defined as a flat or sloping rooftop designed to help support vegetation, in addition to being designed to provide a fully functioning roof for a building (Ismail et al, 2010;Kamarulzaman et al, 2014). Snodgrass and McIntyre (2010) state that a green roof is characterized by plants on the top layer of the roof, or by a roof covered by vegetation in a layer of soil or growing medium in order to enhance roof performance as well as its appearance.…”

“…Limiting the exploration to the maintenance of green roofs, several elements or maintenance items were ascertained. For example, a study carried out by Kamarulzaman et al (2014) pointed out that vegetation, the growing medium, filter mats, drainage layer, insulation, root barrier and waterproof membrane were the main criteria needed in the maintenance of green roofs. Meanwhile, Ismail et al (2016) highlighted several other elements or criteria, such as roof slabs, waterproofing membrane, drainage system, fertilization, pruning, weed control and irrigation system.…”

“…An intensive green roof may use any type of plant, including shrubs, perennials and trees. Meanwhile, extensive green roofs generally use drought resistant plants with shallow roots, such as sedums and lawns (Kamarulzaman et al, 2014). Therefore, it important to acknowledge the types of vegetation and their suitability before they are installed on the green roof, as this will determine the different approaches of vegetation maintenance.…”

“…As stated by Herman (2003), about 14% of all flat roofs in Germany have adapted the green approach and the supportive government policies have made it typical to have green roofs in cities. At the same time, over the past few decades, green roofs have become well accepted and more popular across Europe (Kamarulzaman et al, 2014). Furthermore, Getter & Rowe (2006) also mention that the roof area in most urban regions would usually constitute around 21%26% of the total area.…”

Contribution of local knowledge towards urban agroforestry as a sustainable approach on climate change adaptation

“…Implementation and maintenance of urban agroforestry provide much needed shade and improve evapotranspiration, thus reduce the heat island effect. This is a form of passive cooling approach to reduce high temperature in urban areas [26]. Besides that, other particles such as carbon dioxide and dust are captured.…”