• Energy Research
• 7. Clean energy close

Abstract Green roofs (GRs) have several private, environmental, and social benefits, though financial issues have been considered a major barrier to its widespread use. The lack of knowledge and information regarding the value and applicability of each such benefit has resulted in limited adoption of GRs in Malaysia. Hence, the aim of this research is to analyse the financial feasibility of GR installation, considering social and private perspectives (where the applicability of benefits varies across various scenarios). To do that, the applicable short- and long-term costs and benefits of GRs were identified through reviewing the literature. Then, the variables’ values were investigated and calculated using Monte Carlo simulation. GRs’ net present value (NPV) and discounted payback period (DPBP) were analysed in different private scenarios to derive its financial feasibility out in Kuala Lumpur. Additionally, projected social benefits were analysed to indicate the government’s financial benefit from GR adoption. The results showed that NPV for the private sector could be up to $1072.44 m2 and $735.11 m2, while it is most likely around $390.78 m2 and $258 m2 for intensive GR (IGR) and extensive GR (EGR), respectively. Most probably, the DPBP would be between one and nine years and one and six years for IGR and EGR, respectively. Additionally, considering the social benefits of GR, IGR has the potential to offer up to $314 m2; the amount is much lower for EGR at $55 m2. Moreover, it was found that energy saving is the most influential variable affecting NPV in private and social perspectives. Finally, it was concluded that GR installation could be financially feasible if all private benefits are applicable. Since GR has social financial benefits, the initial costs could be partially covered by the government as an incentive for GR installers.

Abstract This paper presents a comprehensive review of the significant studies exploited Artificial Neural Networks (ANNs) in BEA (Building Energy Analysis). To achieve a full coverage of the relevant studies to the scope of the research, a three-decade time span of the publishing date of the existing studies was taken into account. The review focuses on the studies utilized ANN to analyze the energy-related issues associated with buildings in major areas, including modeling of water heating and cooling systems, heating and cooling loads prediction, modeling heating ventilation air conditioning systems, indoor air temperature prediction, and building energy consumption prediction. Moreover, the findings of the abundant reviewed studies along with the potential future research to be carried out are discussed elaborately. Regarding the comprehensive review conducted, it is found out that the majority of studies focused on building energy consumption and indoor air temperature prediction. Additionally, it is observed that there has been a growing interest in the application of newly-developed ANNs to BEA areas, such as general regression neural network and recurrent neural network, due to their abilities in improving the modeling and prediction of buildings energy analysis. It is believed that this thorough review paper is useful for the researchers and scientific engineers working on the application of AI-based techniques to the building-energy-related areas to find out the relevant references and current state of the field.

Green roofs are known as one of the environmentally-friendly applications and also as a sustainable approach in developing countries. Although many researchers have proven the environmental benefits of installing green roofs all around the world, they have not been used widely in many countries due to the lack of knowledge about cost-benefit issues. This paper places an emphasis on all the private factors affecting cost-benefit analysis. Installation, operation and maintenance costs are compared with the benefits such as energy saving, the increase in property value, and the acoustic effect in order to determine two indicators namely “net present value” and “pay-back period,” using the Monte Carlo simulation. Two scenarios are considered in the analyses: using the property, and selling the property after construction. Moreover, correlation and regression sensitivity analyses are also conducted. The capital of Malaysia, Kuala Lumpur, is selected for the case study due to the lack of cost-benefit analysis in developing countries. The results show that there is low probability of loss in the installation of both types of green roofs during their lifespans. Moreover, net present value for intensive green roofs is found to be higher than extensive ones, whereas the payback period for installing extensive green roofs is lower than intensive green roofs. It is concluded that the probability of loss for the owner is higher than that of benefit in the scenario of selling the property after construction resulting from the installation of both types of green roofs.

Abstract The benefits (B), opportunities (O), costs (C), and risks (R) of green roof (GR) installation have been identified by several studies. However, the inner-dependencies among them, potentially significant in the decision-making process for proper adoption of GRs, have not yet been investigated. In view of this gap, this study investigates the inner-dependencies between the BOCRs of GR installation according to Malaysian experts. BOCRs were collated through a review of the literature and categorized into 11 groups. The enhanced fuzzy Delphi method (EFDM) and fuzzy decision-making trial and evaluation laboratory (FDEMATEL) approaches were utilized to investigate the inner-dependencies. The EFDM results revealed that 28 BOCRs were perceived as significant, while the investigation of inner-dependencies showed that stormwater management, contribution to mitigation of urban heat islands, additional structural support, and irregular maintenance were the most influential B, O, C, and R, respectively. Notably, no significant relationships were found among environmental and economic opportunities. FDEMATEL results showed that, to take full advantage of GR installation, the primary focus should be on the most influential (rather than important) Bs and Os. The findings of this research provide stakeholders with insights into the adoption of GR installation, bringing not only environmental benefits but financial upsides.

In recent years, many researchers across the world have addressed the implementation of Building Information Modelling (BIM) in the energy assessment of the built environment. However, several potential issues still need to be resolved in order to utilise the benefits provided by BIM to a maximum degree. To fill this gap, a systematic literature review is conducted in this study to critically investigate the utilisation of BIM tools in energy assessment. To achieve the above-mentioned objective, after shortlisting the relevant papers published hitherto, using keyword searching, a systematic review was undertaken, including the application of BIM in the contexts of different countries, types of BIM tools, BIM and Life Cycle Assessment (LCA) integration, energy affiliations, stakeholders’ involvement and their roles, uncertainty, and sensitivity analysis. The outcomes show the most widely used and effective BIM tools in different types of construction projects in various countries. The review of the literature clearly shows that BIM tools can effectively be used in the assessment of energy performance of buildings. The article gives insight to engineers, architecture, and decision makers to carefully select appropriate BIM tools in terms of energy assessment.