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Sri Lanka is experiencing a construction boom and there are many high-rise building constructions coming up. Thus, many adverse effects are associated with high rise buildings. Greenery provides several benefits to the environment and reduces these effects. However due to limited space in urban areas it is impossible to plant new plants, trees and...
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Purpose
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Green roofs are increasingly being used in urban settings because of the many benefits they are capable of providing. Because of their widespread use, the issue of how to conduct proper disposal of green roofs once they have reached their end of life is beginning to be raised. The present study is a review of the scientific literature published bet...
Climate change and urbanization are the main problems of the city that have caused the Urban Heat Island effect (UHI). A green roof that utilizes the building roof as a green space can overcome the UHI effects. Green roof is also an efficient solution in the procurement of green spaces in crowded cities. In 2019, Semarang City Mayor released regula...
A contribution to the sustainable management of storm water is the use of sustainable drainage (SuDS)-derived water as an unconventional source for irrigation. If storm-water runoff contains dissolved nutrients in excess of those found in conventional irrigation, reusing this water can contribute to the nutrient demands of horticulture or landscapi...
Citations
... For example, Wijerathne and Halwatura (2011) experimented to measure the variation of CO2 in greenery areas against city junctions and acknowledged that green roof implementation is beneficial to the cities of Sri Lanka. Subsequently, Subaskar (2017) has examined the applicability of green roofs to Sri Lankan high-rise buildings through an opinion survey. In addition, some of the studies have assessed the benefits of green roofing such as life cycle costing, mitigation of the urban heat island effect, and thermal performance of green roofing (Dareeju et al., 2011a;Halwatura, 2013). ...
... Further, green, living, or eco-friendly roofs are used to provide durability, longevity, and aesthetics to buildings and those can be incorporated into new or existing buildings (Patnaik et al., 2018). Also, green roofs act as a solar protection cover that contributes to mitigating urban warming and cooling the ambient air (Subaskar, 2017). According to Almusaed and Almssad (2018), the origin of the green roof concept come over a long time. ...
Green roofs are one of the green practices, having widespread use in the European and Asian regions due to their numerous benefits. However, country like Sri Lanka is yet to experience its optimum potential application. Thus, this study investigates the application of green roofs in Sri Lanka in terms of current status of its application, role in the green rating systems and implementation barriers to enhance its application in Sri Lanka. Initially, a preliminary survey, followed by semi-structured interviews with green roof construction professionals was conducted where the collected data were analysed using descriptive data analysis techniques. Amongst the identified set of applications, residential and commercial buildings are the most common building types with the extensive and semi-intensive green roof types. Although the most commonly used rating systems of GREENSL® and LEED have various provisions, a very few out of number of buildings surveyed have incorporated green roofs. According to the green roof construction professionals, the application is limited in the Sri Lankan buildings due to fourteen (14) key barriers. Amongst those barriers, higher initial and maintenance costs, poor awareness of the public on the concept and lack of clients’ willingness on the concept are the mostly identified barriers by the interviewees. Hence, the study recommends taking necessary actions to mitigate the barriers in order to enhance the green roof applications on the Sri Lankan buildings to optimise the multiple benefits if offers.
... The principles of sustainable construction have been divided into four pillars: social, economic, biophysical, and technological. According to Vidyaratne and Melagoda (2018), green roofs, which are becoming increasingly popular in Sri Lankan high-rise building and it has gained increasing attention as a sustainable solution for development projects, as they offer numerous environmental benefits such as reducing energy consumption, mitigating the urban heat island effect, and improving air quality. However, poor design and construction can significantly impact the future maintainability of green roofs (Mohanta & Das, 2022). ...
... In the context of high-rise buildings, specific design considerations may be required to address the unique challenges associated with their height and structural complexity (Vidyaratne & Melagoda, 2018). These considerations may include safe access points for maintenance personnel, efficient water and drainage systems, and appropriate plant selection that can withstand the exposure to wind and sun at greater heights. ...
... Construction related factors (CRFs) play a crucial role in the maintenance of green roofs, and their influence should be considered during the planning and installation phases (Conejos & Chew, 2020). In this context, this paper identifies some of the key CRFs that influence the maintainability of green roofs as shown in Table 2. (Vidyaratne & Melagoda, 2018) According to Table 2, considering these CRFs during the design and installation of green roofs can help ensure that they are easy to maintain and provide long-lasting benefits. For example, CRF1, which refers to the structure and weight of the roof, can influence the overall stability and load-bearing capacity of the green roof. ...
Poor design and construction practices can significantly impact the future maintainability of green roofs in high-rise buildings. While previous studies have focused on green roof construction and design features, this research specifically evaluates the effects of design and construction related factors on maintainability of green roofs, with a focus on high-rise buildings in Sri Lanka. The study begins by reviewing literature on green roofs, their maintainability, and the design and construction factors that influence maintainability. The identified factors were used as a basis for evaluating the effects of design and construction on future maintainability of green roofs. A deductive approach is adopted within a quantitative research design, utilising a survey strategy. A questionnaire survey was conducted among 58 experienced construction professionals, while four expert interviews are conducted to gather additional insights. Data analysis techniques include the Relative Importance Index and content analysis. As derived through analysis, initial cost and roof design were identified as design-related key factors, while cost of construction and availability of machinery and materials were the construction related key factors influencing maintainability of green roofs. Accordingly, the study proposed strategies to enhance the maintainability of green roofs in Sri Lankan high-rise buildings focusing on cost effectiveness, design effectiveness and effective management of green roofs. As a main implication, this research contributes to the development of sustainable and maintainable green roofs in Sri Lanka by providing valuable insights for the construction professionals and policy makers in the country.
... A large number of studies have argued the benefits of UGI on people, built environment, and urban environment [1], [5], [6], [11], [12], [23], [24]. Worldwide extensively to mitigate the negative impacts of urban sprawl and achieve resilient and sustainable cities through: ...
... Delaying water runoff in buildings would mitigate the flow volume into stormwater infrastructure and urban waterways, thus reducing flood risk [6]. Moreover, UGI can not only retain water and reduce the rate of runoff but also improve the water quality by buffering acidic rain, theoretically filtering pollutants and suspended solids [1], [5], [11], [12], [26]. ...
... Air pollution in compacted cities of the Global South is even worse due to much-outdated transportation means releasing poisonous gases into the environment [32]. Among several mitigation technologies, UGI is a popular approach that could help to mitigate air pollution in urban environments by carbon sequestration, dust removal and pulling down levels of gaseous pollutants such as nitrogen oxides, lead and zinc [2], [3], [5], [9], [10], [12], [15] [23], [33]. ...
The wellbeing of urban dwellers is strongly associated with the quality and quantity of green infrastructure. Nevertheless, urban green infrastructure is still lagging in many Arab cities, and Jordan is no exception. The capital city of Jordan, Amman, is becoming more urban dense with limited green spaces. The unplanned urban growth in Amman has caused several environmental problems such as urban heat islands, air pollution and lack of green spaces. This study aims to investigate the most suitable drivers to leverage the implementation of urban green infrastructure in Jordan through qualitative and quantitative analysis. The qualitative research includes an extensive literature review to discuss the most common drivers used internationally to promote urban green infrastructure implementation in the literature. The quantitative study employs a questionnaire survey to rank the suitability of each driver. Consultants, contractors and policymakers were invited to fill the research questionnaire according to their judgments and opinions. Relative Importance Index has been used to calculate the weighted average of all drivers and the Kruskal-Wallis test to check the degree of agreement among groups. This study finds that research participants agreed that indirect financial incentives (i.e., tax reductions, reduction in stormwater utility fee, reduction of interest rate, density bonus etc.) are the most effective incentive policy whilst granting sustainability certificate policy is the least effective driver to ensure widespread of UGI is elements in Jordan.
... Further, [14] examined the applicability of green roofs to Sri Lankan high-rise buildings. However, this study, which is limited to an opinion survey, did not take into consideration the different types of green roofs or focus on the assessment of benefits. ...
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.
Green infrastructure is acknowledged as a new strategy to address the environmental issues currently dominating in urban resilience. Green roofs are one of the many nature-based remedies that effectively reduce the negative effects of improper development. An enclosed vegetative area on top of a constructed environment is what is meant by a "green roof system." In Sri Lanka, some of the primary problems facing municipal areas, which demand quick correction, are flash flooding, heat island effect, poor air quality, and aesthetic disruptions. By implementing green roofs effectively, such conditions can be changed and the economic, social, and environmental sustainability of urban dwellings can be significantly improved. Based on existing literature from 2010 to 2020, this review seeks to determine the role of green roofs in improving the sustainability of urban centers in Sri Lanka. The scope of the study includes a thorough, holistic, and thematic analysis of the idea of green roofs and facades. The research is divided into several subfields which discuss energy saving, thermal comfort features, stormwater retention, air quality improvement and noise reduction. Moreover, the environmental and socioeconomic potential and constraints are identified, and the feasibility of creating green roofs in Sri Lanka is discussed. The potential is centered on improved ecological performance, climate change mitigation, recreation, and a favorable impact on urban livelihood through stormwater management. The constraints emphasize the initial costs of green roof which tend to be expensive and requires extra maintenance than traditional roof system. A sophisticated adaptation of green roofs with unique designs that are appropriate for Sri Lankan conditions is recommended in this review in order to improve the quality of life of urban communities.
In twenty-first century buildings, green roof systems are envisioned as great solution for improving Environmental sustainability in urban ecosystems and it helps to mitigate various health hazards for humans due to climatic pollution. This study determines the feasibility of using five domestic organic wastes, including sawdust, wood bark, biochar, coir, and compost, as sustainable substrates for green roofs as compared to classical Sri Lankan base medium (fertiliser + potting mix) in terms of physicochemical and biological parameters associated with growing mediums. Comprehensive methodologies were devised to determine the thermal conductivity and electric conductivity of growing mediums. According to preliminary experimental results, the most suitable composition for green roof substrates comprised 60% organic waste and 40% base medium. Sawdust growing medium exhibited the highest moisture content and minimum density magnitudes. Biochar substrate was the best performing medium with the highest drought resistance and vegetation growth. The wood bark substrate had the highest thermal resistance. Growing mediums based on compost , sawdust, and coir produced the best results in terms of nitrate, phosphate, pH, and electric conductivity (EC) existence. This study provided a standard set of comprehensive comparison methodologies utilising physicochemical and biological properties required for substrate characterization. The findings of this research work have strong potential in the future to be used in selecting the most suitable lightweight growing medium for a green roof based on stakeholder requirements.
Jordanians live in compact cities with limited green spaces causing several environmental problems that deteriorate the urban quality of life. Many reports and studies demonstrate the benefits of urban green infrastructure (UGI) in overcoming environmental deterioration in compacted cities. Nevertheless, Urban Green Infrastructure is still lagging in many Arab countries, and Jordan is no exception. UGI refers to a strategically planned network of connected greenspace in urban areas, such as green walls, green roofs, urban trees, and hedges. This study employs the concept of UGI with a particular focus on green walls and roofs. Therefore, this research aims to investigate and determine the key barriers that impede the implementation of UGI in Jordan through qualitative and quantitative analysis. The qualitative study aims to elaborate on root causes that hinder the application of UGI. The quantitative part of the study employs a questionnaire survey to rank the significance of each barrier. This study finds that the shortage of irrigation water and the absence of incentive programs by local authorities were the top two barriers that impede the application of UGI in Jordan.
