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WITHDRAWN: Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran
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Pacific Science Review A: Natural Science and Engineering xxx (2016) 1e5
55 56 57 58 59 j o u r n a l h o m e p a g e : w w w . j o u r n a l s . e l s e v i e r . c o m / p a c i fi c - s c i e n c e 60 review-a-natural-science-and-engineering/ 61 62 63 64 65 66 67 Q11 68 69 * 70 Q10,1 Mina Nazari , Ravanshadnia Mehdi 71 Q2 Engineering Department, Islamic Azad University of Karaj, Iran 72 73 74 a r t i c l e i n f o a b s t r a c t 75 76 Article history: With the increase in human and industrial activities, and as a result of global warming and environ77 Received 16 July 2016 mental pollution, which pose many serious risks for health, safety and human life, construction activities Accepted 8 September 2016 78 are rapidly changing the shape of the earth, and the construction industry consumes half of the world's Available online xxx 79 physical resources. Therefore, with the aim of promoting the green movement in the construction in80 dustry, in this study, a list of sustainable construction methods were assessed in terms of feasibility for Keywords: use in green buildings in Tehran. In addition, considering a building as a case study, the economic 81 Green buildings feasibility and benefits of building a green building in Tehran are expressed using the software Kamfar. 82 Sustainable building Copyright © 2016, Far Eastern Federal University, Kangnam University, Dalian University of Technology, 83 Technical feasibility Kokushikan University. Production and hosting by Elsevier B.V. This is an open access article under the CC Economic feasibility 84 BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Tehran 85 Sustainable construction methods 86 87 88 89 performance is considered. Stable performance based on an 1. Introduction 90 acceptable level of environmental impact, technical feasibility and 91 reasonableness of the expenses necessary for construction should The process of constructing sustainable buildings consistent 92 be in line with the convenience and comfort of residents [3]. according to the environmental thinking of our country has existed Q4 93 for many years, leading to works on the windward of Yazd, the This article uses the results of a questionnaire and applies 94 Kashan houses and the smart geographical orientation of old Kamfar 3 to present the technical and economic feasibility of using 95 houses. Unfortunately, since the advent of industrialization, this art sustainable construction methods for green buildings in Tehran. 96 has been abandoned and replaced by using unprincipled and 97 copycat architecture as well as the inappropriate use of industrial 1.1. Sustainability and sustainable development 98 materials, regardless of the climate and culture, bring about the 99 slow death of the rich and beautiful environment of Iran. The word sustainable is derived from the Latin sustenere, which 100 The construction industry accounts for the largest share of means to exist and be maintained in a situation or known condi101 consumption of natural resources and has the greatest impact on tion. In construction, sustainability is a term that is applied to 102 the natural environment. Increasing human awareness to envibuildings that are economically effective, efficient and excellent in 103 ronmental issues, destruction and reduction of natural resources, terms of the environment, health and technical implementation. 104 global warming and increasing levels of pollution have led to social According to this definition, sustainable development satisfies 105 problems and the implementation of strict rules to ensure that the needs of the present without compromising the ability of future 106 activists in the construction industry pay greater attention to generations to meet their needs. Strategies to meet these needs 107 environmental issues. The performance of buildings is a major have been provided by researchers around the world. 108 concern in the construction industry today, and in this regard, to Green buildings can be part of a broader sustainable devel109 achieve sustainable development, the environmental sustainability opment [5]. Iran, as a developing country, has rich oil and gas 110 resources, but is faced with very high energy consumption and 111 inefficiency in the utilization of energy resources and produces 112 an enormous quantity of environmental pollution, especially in 113 * Corresponding author. Q3 large cities. Iran thus requires greater attention to energy effiE-mail addresses: [email protected] (M. Nazari), [email protected] 114 ciency, the use of available renewable energy and movement (R. Mehdi). 115 towards achieving sustainable buildings to achieve sustainable Peer review under responsibility of Far Eastern Federal University, Kangnam 116 development. University, Dalian University of Technology, Kokushikan University. 117 118 http://dx.doi.org/10.1016/j.psra.2016.09.009 119 2405-8823/Copyright © 2016, Far Eastern Federal University, Kangnam University, Dalian University of Technology, Kokushikan University. Production and hosting by Elsevier H O S T E D BY
Contents lists available at ScienceDirect
Pacific Science Review A: Natural Science and Engineering
Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran
B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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M. Nazari, R. Mehdi / Pacific Science Review A: Natural Science and Engineering xxx (2016) 1e5
1.2. Green and sustainable buildings Currently, green buildings are considered to be flagships for sustainable development and to create a balance between environmental health and economical and social issues. Perhaps it can be said that green buildings are a subset of sustainable buildings that confirm plans that have considered the importance of solar energy, natural lighting and ventilation; reduced consumption and thereby reduced environmental pollution as well as the use of recycled materials; and in general, considered issues related to the environment. Sustainable buildings can be defined as a subset of sustainable development that focuses on balancing environmental, social and economic issues [1]. In short, the aim of green and sustainable buildings is the ability to integrate and adapt buildings to environmental factors and climate resolutions and convert them for space and comfort. In these structures, human comfort is provided through the design, use of efficient equipment, healthy air and appropriate action in usage according to the type of building [10]. The areas of sustainable performance of the buildings that are considered in this paper are energy, the environment, welfare, health and safety.
1.3. Global approaches to green and sustainable buildings Researchers started to use terms such as green, environmentally friendly and sustainable in 1995; hence, it has been more than 20 years since the issue of sustainable buildings has been introduced in developed countries. For example, the society of green buildings of the United States (USGBC) was established in 1993 by stakeholders in the construction industry who were interested in promoting sustainable buildings. Many evaluation systems have been developed over the past two decades with regard to attention to environmental issues in addition to indicators that have been used to assess structures and complexity. In 1990, for the first time, the BREEAM system was comprehensively developed in the United Kingdom and used for evaluating the performance of buildings and to enact a framework for granting certificates for green buildings [2]. Accordingly, other systems were developed in various countries, including LEED and Green Star, which have the highest use and popularity. The LEED standard in America was developed by the Green Building Council in 1993. These systems certify the sustainability performance of buildings in ascending order in terms of sustainability in four categories: certified, silver, gold and platinum.
1.4. An economic analysis of green buildings According to [7]; the cost of green projects versus conventional construction ranges from 1 to 25 percent due to the complexity of the design, modelling reasons for applying green concepts in project studies [9] as well as the use of green materials and technologies [6]. Zhang also calculated that the use of green materials increases the manufacturing cost by 3e4 percent [9]. Some green materials were even 10 times more expensive than traditional types [6]. Thirty-three LEED-certified buildings in California were investigated, and as a result, the initial cost of the average of all of the levels certified is less than 2 percent [8]. The study also noted that LEED-certified buildings averaged energy savings of 30%, carbon reduction of 35%, water savings of 30e50 % and had 50e97 % less waste from construction and operation [8].
Taking into account all LEED and non-LEED projects, Dios found that the green level does not necessarily determine the initial cost (Dios, 2004e2007). Fedrizzi divided the benefits of green buildings into two groups, namely, health benefits and financial benefits. They considered increasing the cost of green buildings versus conventional buildings with decreasing trends of time and stated that there is the possibility to build green buildings with fixed budgets [4]. 2. Questionnaire framework To obtain the required information and summary data in this study, a questionnaire was designed to the target a particular audience, that is, activists in the building industry. The questionnaire framework had five sections as follows. The first part contained an introduction and brief questionnaire about green buildings and LEED standards to help aid completion of the questionnaire. In the second part, the criteria for green buildings in the city's architecture and urban planning in Tehran were considered. The criteria included assessing building usage, issues attractive for sustainability, the most significant advantages of a green building in Tehran, the best areas for sustainable construction, and obstacles and pollution. The third part of the questionnaire examined energy standards, energy dissipation issues and green energy sources in Tehran. The fourth part of the questionnaire contained criteria for green building materials and construction methods. This section examined issues of water resources management, ventilation, sustainable construction methods and green materials. The fifth part of the questionnaire included respondents' personal information, such as gender, discipline, program, activities, work experience and their familiarity with green buildings and LEED standards. The questionnaire was prepared using the Google forms format, which is a strong program with very useful and updated tools for preparation and distribution of questionnaires. 3. Analysis of the questionnaire results This study attempted to draw attention to the technical feasibility of using sustainable building methods in green buildings in Tehran. The output obtained from the questionnaire was completed by 54 participants in the construction industry, the results of which indicate that pollution caused by carbon pollution is the most important pollution of Tehran's buildings in the central regions (6, 7, 8, 9, 10, 11, 12, 16 and 17) of Tehran, and for the materials and resources, the main obstacle to sustainability is the lack of infrastructure and proper culture. The main advantage of green buildings is energy performance in Tehran, and the development of green spaces and parking plays a positive role in promoting green construction. In the buildings of Tehran, most energy waste is from the exterior walls and windows of buildings. For the energy planning regime (cultural consumption), the use of clean solar energy, especially for electricity, can greatly reduce energy waste. Due to the water shortage in the country, the use of wastewater recycling systems (greywater) is the best method to reduce water loss and take advantage of the intelligent ventilation air conditioning in the interior of the building. Destruction management and the collection and use of recycled materials, green concrete in the structure, green and light expanded clay concrete blocks, thermochromic and smart coatings for insulation of windows and interior, vertical green spaces in front
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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and open green roofs are the best methods for sustainable construction of green buildings in Tehran. 4. Green building information With respect to this research, green building features in Tehran were sampled. The LEED standards for green buildings to meet the green points were divided into 4 groups. The scenarios in this study were developed based on the classification shown in Table 1. In Iran and the city of Tehran, experience regarding constructing green buildings is limited and the cost of using green technology is higher than the world's average. In addition, due to the high cost of land and housing compared to developed countries, the rate of increase of the building cost is related to buildings under the LEED standard in America in 2000 (Table 2) for the scenarios considered in this study. Based on the information provided by USGBC, green buildings reduce water consumption by up to 16 %, the cost of building maintenance by 12 % and energy costs by 11 % (electricity and gas). By performing a simple interpolation of the above-mentioned percentages, the amount of savings in each of the four LEEDcertified buildings are presented in accordance with Table 2. 5. Economic analysis
Q6
By measuring the project life cycle costs (LCCA), the costeffectiveness of the project considering the increases in construction costs and life-cycle costs, including reduced energy costs and building maintenance costs, can be investigated. This simple measurement to evaluate the return on investment or advanced level is determined using the time value of money and the output rate of the return NPV, and the internal rate of return IRR is obtained. In this study, the net present value and internal rate of return were investigated through a sensitivity analysis and economic feasibility study. In reference to the World Energy rate, which is 7 % higher than that of Iran, the NPV and IRR of each defined scenario assuming a power rate increase of 3 % increased by 5 % and 7 %, respectively. 5.1. NPV and IRR analysis scenario By entering the information of the sample under study hypotheses for the scenarios consistent with the information stated in Section 5, the IRR and NPV were obtained (Figs. 1 and 2, respectively). Positive NPV and IRR scenarios are acceptable. Through the promotion of LEED-certified green buildings, the percentage decrease in IRR reflects reduced the economic efficiency of the project.
Table 1 Scenarios of research. Scenario
Scenario description
Required score
Increased construction cost
Base First
Conventional building Building receives Leed certificate Building promoted to silver certificate level Building promoted to gold certificate level Building promoted to platinum certificate level
0 40e49 score
0 2%
50e59 score
4%
60e70 score
7%
80þ score
9%
Second Third Fourth
3
66 67 68 Scenario Increase cost Description Reduction of of construction consumption cost 69 70 Base 0 e 0 First 2% Water 7% 71 Energy 5% 72 Repair 5% 73 Second 4% Water 12% 74 Energy 8% 75 Repair 9% Third 7% Water 14% 76 Energy 10% 77 Repair 11% 78 Fourth 9% Water 16% 79 Energy 11% 80 Repair 12% 81 82 83 84 85 86 87 88 89 90 91 92 93 Q8 Fig. 1. Diagram scenarios NPV. 94 95 96 97 98 99 100 101 102 103 104 105 106 107 Fig. 2. Diagram IRR scenarios. 108 109 110 According to the data shown in Fig. 3, which show the internal 111 rate of return IRR scenarios, taking the initial investment into ac112 count, a more attractive rate of return of MARR (assuming current 113 interest of 25%) is acceptable. Through the promotion of LEED114 certified buildings, and thus the green extent of the buildings, the 115 percentage decreased, suggesting that the IRR of the project was 116 reduced in terms of economic output, but was still positive, indi117 cating that the rate of return is greater than the minimum attractive 118 rate of return. 119 120 121 122 5.2. NPV and IRR analysis scenarios changes with regard to 123 increasing energy costs 124 125 Figs. 3 and 4 of rising energy costs and water consumption were 126 obtained by applying a rate of 3, 5 and 7 percent, according to Tables 3 and 4, respectively (see Fig. 5). Q7 127 128 With rising energy costs, the net present value remains positive 129 and is acceptable in all four scenarios, with low slopes that show 130 almost identical increases. Table 2 Percentage increase costs and reduce energy costs.
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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6. Conclusions and recommendations
Fig. 3. Diagram IRR scenarios, including initial investment.
Fig. 4. Diagram scenarios NPV changes to the rising cost of energy.
Fig. 5. Diagram IRR change scenarios than the rise in energy costs.
Table 3 NPV change scenarios for the rise in energy costs. Energy cost increase
First scenario
Second scenario
Third scenario
Forth scenario
0% 3% 5% 7%
32.08 32.74 33.18 33.63
53.76 54.83 55.55 56.26
66.16 67.48 68.37 69.25
72.9 74.37 75.34 76.32
In this paper, a data questionnaire of a set of sustainable construction methods with the possibility of using them in green buildings in Tehran is presented in accordance with the information stated in Section 6. It was found to be economical to use sustainable construction methods in green buildings in Tehran; in addition to the 30 % initial investment (assuming a profit at the time of sale or buyer profits from their investment in buying property), the internal rate of return IRR had a 41.2e77.4 % increase in construction costs and costs of operation, including energy, water and maintenance, and this rate varied inversely with the increase in green characteristics. In other words, as the building increased in terms of the level of LEED certification, the IRR decreased from 77.4 % to 4.2 %. Additionally, increasing energy costs affect the IRR; by increasing energy costs, the internal rate of return increases by 23.0 %. With regard to the interests of the environment and human health, green construction finance officials also recommended further work in the field of infrastructure and culture for sustainability by applying stricter rules and expanding loans and discounts for green buildings to contribute their development. In addition, due to positive internal rate of return observed from the reduced energy consumption, increasing energy prices close to the world rate are reasonable and will substantially help the government. This benefit may help finance infrastructure or provide loans and discounts to green buildings. According to the methods presented, the approach to implementing sustainable green buildings in Tehran is proposed and the rate of return is calculated. It is suggested that residents deciding to buy a building pay greater attention to the financial interests of health and welfare for green buildings compared to conventional buildings. According to the research data and results, the following is suggested for future research: The legal feasibility of using sustainable building methods in Iran; Comparison of sustainable economic construction under the LEED green buildings and non-LEED buildings in Iran; The technical, economic and legal feasibility of using LEED standards in Iran; Investigating the economic benefits of the stabilization and increased energy cost savings as a result of the development of green buildings.
Uncited reference [11].
With increasing energy costs, the internal rate of return is still positive and acceptable in all four scenarios, with low slopes that show identical increases. This rate of increase is less than that in each of the four cases in which the consumer does not make much appeal, but will have many resources at the country level. Table 4 Changes IRR scenarios to increase the cost of energy. Energy cost increase
First scenario
Second scenario
Third scenario
Forth scenario
0% 3% 5% 7%
4.77% 4.87% 4.94% 5%
4% 4.08% 4.13% 4.19%
2.81% 2.87% 2.91% 2.94%
2.41% 2.46 2.49% 2.52%
References English resources [1] H.H. Ali, S.F. Al Nsairat, Developing a green building assessment tool for developing countries-case of Jordan, Build. Environ. 44 (5) (2009) 1053e1064. [2] BREEAM, Building Research Establishment Environment Assessment Method, 1990. [3] Y. Chen, G.E. Okudan, D.R. Riley, Sustainable performance criteria for construction method selection in concrete buildings, Automation Constr. 19 (2) (2010) 235e244. [4] R. Fedrizzi, j. Karistrom, k Brown, The Business Case for Green Building: Word Green Building Council, 2013. [5] B.-G. Hwang, W.J. Ng, Project management knowledge and skills for green construction: overcoming challenges, Int. J. Proj. Manag. 31 (2) (2013) 272e284.
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
Q9
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
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M. Nazari, R. Mehdi / Pacific Science Review A: Natural Science and Engineering xxx (2016) 1e5 [6] B.G. Hwang, J.S. Tan, Green building project management: obstacles and solutions for sustainable development, Sustain. Dev. 20 (5) (2012) 335e349. [7] E. Tagaza, J. Wilson, Green buildings: drivers and barriers e lessons learned from five melbourne developments, in: Report Prepared for Building Commission by University of Melbourne and Business Outlook and Evaluation, 2004. [8] USGBC. From http://www.usgbc.org/leed. [9] X. Zhang, L. Shen, Y. Wu, Green strategy for gaining competitive advantage in housing development: a China study, J. Clean. Prod. 19 (2) (2011) 157e167.
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Persian references [10] Ghaemi, (1391) reportStudy the Design and Construction of Green Buildings Based on the Identification and Assessment of Structural Stability Performance Criteria in Iran, Tehran University, (Masters). [11] Erabi (1394) Analyze and Evaluate the Technical and Economic Challenges in the Application of Intelligent Building Management Systems in the Approach to Optimize Energy Consumption, Islamic Azad University of Karaj, MA.
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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55 56 57 58 59 j o u r n a l h o m e p a g e : w w w . j o u r n a l s . e l s e v i e r . c o m / p a c i fi c - s c i e n c e 60 review-a-natural-science-and-engineering/ 61 62 63 64 65 66 67 Q11 68 69 * 70 Q10,1 Mina Nazari , Ravanshadnia Mehdi 71 Q2 Engineering Department, Islamic Azad University of Karaj, Iran 72 73 74 a r t i c l e i n f o a b s t r a c t 75 76 Article history: With the increase in human and industrial activities, and as a result of global warming and environ77 Received 16 July 2016 mental pollution, which pose many serious risks for health, safety and human life, construction activities Accepted 8 September 2016 78 are rapidly changing the shape of the earth, and the construction industry consumes half of the world's Available online xxx 79 physical resources. Therefore, with the aim of promoting the green movement in the construction in80 dustry, in this study, a list of sustainable construction methods were assessed in terms of feasibility for Keywords: use in green buildings in Tehran. In addition, considering a building as a case study, the economic 81 Green buildings feasibility and benefits of building a green building in Tehran are expressed using the software Kamfar. 82 Sustainable building Copyright © 2016, Far Eastern Federal University, Kangnam University, Dalian University of Technology, 83 Technical feasibility Kokushikan University. Production and hosting by Elsevier B.V. This is an open access article under the CC Economic feasibility 84 BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Tehran 85 Sustainable construction methods 86 87 88 89 performance is considered. Stable performance based on an 1. Introduction 90 acceptable level of environmental impact, technical feasibility and 91 reasonableness of the expenses necessary for construction should The process of constructing sustainable buildings consistent 92 be in line with the convenience and comfort of residents [3]. according to the environmental thinking of our country has existed Q4 93 for many years, leading to works on the windward of Yazd, the This article uses the results of a questionnaire and applies 94 Kashan houses and the smart geographical orientation of old Kamfar 3 to present the technical and economic feasibility of using 95 houses. Unfortunately, since the advent of industrialization, this art sustainable construction methods for green buildings in Tehran. 96 has been abandoned and replaced by using unprincipled and 97 copycat architecture as well as the inappropriate use of industrial 1.1. Sustainability and sustainable development 98 materials, regardless of the climate and culture, bring about the 99 slow death of the rich and beautiful environment of Iran. The word sustainable is derived from the Latin sustenere, which 100 The construction industry accounts for the largest share of means to exist and be maintained in a situation or known condi101 consumption of natural resources and has the greatest impact on tion. In construction, sustainability is a term that is applied to 102 the natural environment. Increasing human awareness to envibuildings that are economically effective, efficient and excellent in 103 ronmental issues, destruction and reduction of natural resources, terms of the environment, health and technical implementation. 104 global warming and increasing levels of pollution have led to social According to this definition, sustainable development satisfies 105 problems and the implementation of strict rules to ensure that the needs of the present without compromising the ability of future 106 activists in the construction industry pay greater attention to generations to meet their needs. Strategies to meet these needs 107 environmental issues. The performance of buildings is a major have been provided by researchers around the world. 108 concern in the construction industry today, and in this regard, to Green buildings can be part of a broader sustainable devel109 achieve sustainable development, the environmental sustainability opment [5]. Iran, as a developing country, has rich oil and gas 110 resources, but is faced with very high energy consumption and 111 inefficiency in the utilization of energy resources and produces 112 an enormous quantity of environmental pollution, especially in 113 * Corresponding author. Q3 large cities. Iran thus requires greater attention to energy effiE-mail addresses: [email protected] (M. Nazari), [email protected] 114 ciency, the use of available renewable energy and movement (R. Mehdi). 115 towards achieving sustainable buildings to achieve sustainable Peer review under responsibility of Far Eastern Federal University, Kangnam 116 development. University, Dalian University of Technology, Kokushikan University. 117 118 http://dx.doi.org/10.1016/j.psra.2016.09.009 119 2405-8823/Copyright © 2016, Far Eastern Federal University, Kangnam University, Dalian University of Technology, Kokushikan University. Production and hosting by Elsevier H O S T E D BY
Contents lists available at ScienceDirect
Pacific Science Review A: Natural Science and Engineering
Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran
B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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1.2. Green and sustainable buildings Currently, green buildings are considered to be flagships for sustainable development and to create a balance between environmental health and economical and social issues. Perhaps it can be said that green buildings are a subset of sustainable buildings that confirm plans that have considered the importance of solar energy, natural lighting and ventilation; reduced consumption and thereby reduced environmental pollution as well as the use of recycled materials; and in general, considered issues related to the environment. Sustainable buildings can be defined as a subset of sustainable development that focuses on balancing environmental, social and economic issues [1]. In short, the aim of green and sustainable buildings is the ability to integrate and adapt buildings to environmental factors and climate resolutions and convert them for space and comfort. In these structures, human comfort is provided through the design, use of efficient equipment, healthy air and appropriate action in usage according to the type of building [10]. The areas of sustainable performance of the buildings that are considered in this paper are energy, the environment, welfare, health and safety.
1.3. Global approaches to green and sustainable buildings Researchers started to use terms such as green, environmentally friendly and sustainable in 1995; hence, it has been more than 20 years since the issue of sustainable buildings has been introduced in developed countries. For example, the society of green buildings of the United States (USGBC) was established in 1993 by stakeholders in the construction industry who were interested in promoting sustainable buildings. Many evaluation systems have been developed over the past two decades with regard to attention to environmental issues in addition to indicators that have been used to assess structures and complexity. In 1990, for the first time, the BREEAM system was comprehensively developed in the United Kingdom and used for evaluating the performance of buildings and to enact a framework for granting certificates for green buildings [2]. Accordingly, other systems were developed in various countries, including LEED and Green Star, which have the highest use and popularity. The LEED standard in America was developed by the Green Building Council in 1993. These systems certify the sustainability performance of buildings in ascending order in terms of sustainability in four categories: certified, silver, gold and platinum.
1.4. An economic analysis of green buildings According to [7]; the cost of green projects versus conventional construction ranges from 1 to 25 percent due to the complexity of the design, modelling reasons for applying green concepts in project studies [9] as well as the use of green materials and technologies [6]. Zhang also calculated that the use of green materials increases the manufacturing cost by 3e4 percent [9]. Some green materials were even 10 times more expensive than traditional types [6]. Thirty-three LEED-certified buildings in California were investigated, and as a result, the initial cost of the average of all of the levels certified is less than 2 percent [8]. The study also noted that LEED-certified buildings averaged energy savings of 30%, carbon reduction of 35%, water savings of 30e50 % and had 50e97 % less waste from construction and operation [8].
Taking into account all LEED and non-LEED projects, Dios found that the green level does not necessarily determine the initial cost (Dios, 2004e2007). Fedrizzi divided the benefits of green buildings into two groups, namely, health benefits and financial benefits. They considered increasing the cost of green buildings versus conventional buildings with decreasing trends of time and stated that there is the possibility to build green buildings with fixed budgets [4]. 2. Questionnaire framework To obtain the required information and summary data in this study, a questionnaire was designed to the target a particular audience, that is, activists in the building industry. The questionnaire framework had five sections as follows. The first part contained an introduction and brief questionnaire about green buildings and LEED standards to help aid completion of the questionnaire. In the second part, the criteria for green buildings in the city's architecture and urban planning in Tehran were considered. The criteria included assessing building usage, issues attractive for sustainability, the most significant advantages of a green building in Tehran, the best areas for sustainable construction, and obstacles and pollution. The third part of the questionnaire examined energy standards, energy dissipation issues and green energy sources in Tehran. The fourth part of the questionnaire contained criteria for green building materials and construction methods. This section examined issues of water resources management, ventilation, sustainable construction methods and green materials. The fifth part of the questionnaire included respondents' personal information, such as gender, discipline, program, activities, work experience and their familiarity with green buildings and LEED standards. The questionnaire was prepared using the Google forms format, which is a strong program with very useful and updated tools for preparation and distribution of questionnaires. 3. Analysis of the questionnaire results This study attempted to draw attention to the technical feasibility of using sustainable building methods in green buildings in Tehran. The output obtained from the questionnaire was completed by 54 participants in the construction industry, the results of which indicate that pollution caused by carbon pollution is the most important pollution of Tehran's buildings in the central regions (6, 7, 8, 9, 10, 11, 12, 16 and 17) of Tehran, and for the materials and resources, the main obstacle to sustainability is the lack of infrastructure and proper culture. The main advantage of green buildings is energy performance in Tehran, and the development of green spaces and parking plays a positive role in promoting green construction. In the buildings of Tehran, most energy waste is from the exterior walls and windows of buildings. For the energy planning regime (cultural consumption), the use of clean solar energy, especially for electricity, can greatly reduce energy waste. Due to the water shortage in the country, the use of wastewater recycling systems (greywater) is the best method to reduce water loss and take advantage of the intelligent ventilation air conditioning in the interior of the building. Destruction management and the collection and use of recycled materials, green concrete in the structure, green and light expanded clay concrete blocks, thermochromic and smart coatings for insulation of windows and interior, vertical green spaces in front
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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and open green roofs are the best methods for sustainable construction of green buildings in Tehran. 4. Green building information With respect to this research, green building features in Tehran were sampled. The LEED standards for green buildings to meet the green points were divided into 4 groups. The scenarios in this study were developed based on the classification shown in Table 1. In Iran and the city of Tehran, experience regarding constructing green buildings is limited and the cost of using green technology is higher than the world's average. In addition, due to the high cost of land and housing compared to developed countries, the rate of increase of the building cost is related to buildings under the LEED standard in America in 2000 (Table 2) for the scenarios considered in this study. Based on the information provided by USGBC, green buildings reduce water consumption by up to 16 %, the cost of building maintenance by 12 % and energy costs by 11 % (electricity and gas). By performing a simple interpolation of the above-mentioned percentages, the amount of savings in each of the four LEEDcertified buildings are presented in accordance with Table 2. 5. Economic analysis
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By measuring the project life cycle costs (LCCA), the costeffectiveness of the project considering the increases in construction costs and life-cycle costs, including reduced energy costs and building maintenance costs, can be investigated. This simple measurement to evaluate the return on investment or advanced level is determined using the time value of money and the output rate of the return NPV, and the internal rate of return IRR is obtained. In this study, the net present value and internal rate of return were investigated through a sensitivity analysis and economic feasibility study. In reference to the World Energy rate, which is 7 % higher than that of Iran, the NPV and IRR of each defined scenario assuming a power rate increase of 3 % increased by 5 % and 7 %, respectively. 5.1. NPV and IRR analysis scenario By entering the information of the sample under study hypotheses for the scenarios consistent with the information stated in Section 5, the IRR and NPV were obtained (Figs. 1 and 2, respectively). Positive NPV and IRR scenarios are acceptable. Through the promotion of LEED-certified green buildings, the percentage decrease in IRR reflects reduced the economic efficiency of the project.
Table 1 Scenarios of research. Scenario
Scenario description
Required score
Increased construction cost
Base First
Conventional building Building receives Leed certificate Building promoted to silver certificate level Building promoted to gold certificate level Building promoted to platinum certificate level
0 40e49 score
0 2%
50e59 score
4%
60e70 score
7%
80þ score
9%
Second Third Fourth
3
66 67 68 Scenario Increase cost Description Reduction of of construction consumption cost 69 70 Base 0 e 0 First 2% Water 7% 71 Energy 5% 72 Repair 5% 73 Second 4% Water 12% 74 Energy 8% 75 Repair 9% Third 7% Water 14% 76 Energy 10% 77 Repair 11% 78 Fourth 9% Water 16% 79 Energy 11% 80 Repair 12% 81 82 83 84 85 86 87 88 89 90 91 92 93 Q8 Fig. 1. Diagram scenarios NPV. 94 95 96 97 98 99 100 101 102 103 104 105 106 107 Fig. 2. Diagram IRR scenarios. 108 109 110 According to the data shown in Fig. 3, which show the internal 111 rate of return IRR scenarios, taking the initial investment into ac112 count, a more attractive rate of return of MARR (assuming current 113 interest of 25%) is acceptable. Through the promotion of LEED114 certified buildings, and thus the green extent of the buildings, the 115 percentage decreased, suggesting that the IRR of the project was 116 reduced in terms of economic output, but was still positive, indi117 cating that the rate of return is greater than the minimum attractive 118 rate of return. 119 120 121 122 5.2. NPV and IRR analysis scenarios changes with regard to 123 increasing energy costs 124 125 Figs. 3 and 4 of rising energy costs and water consumption were 126 obtained by applying a rate of 3, 5 and 7 percent, according to Tables 3 and 4, respectively (see Fig. 5). Q7 127 128 With rising energy costs, the net present value remains positive 129 and is acceptable in all four scenarios, with low slopes that show 130 almost identical increases. Table 2 Percentage increase costs and reduce energy costs.
Please cite this article in press as: M. Nazari, R. Mehdi, , Technical and economic feasibility of using sustainable construction methods for green buildings in Tehran, Pacific Science Review A: Natural Science and Engineering (2016), http://dx.doi.org/10.1016/j.psra.2016.09.009
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6. Conclusions and recommendations
Fig. 3. Diagram IRR scenarios, including initial investment.
Fig. 4. Diagram scenarios NPV changes to the rising cost of energy.
Fig. 5. Diagram IRR change scenarios than the rise in energy costs.
Table 3 NPV change scenarios for the rise in energy costs. Energy cost increase
First scenario
Second scenario
Third scenario
Forth scenario
0% 3% 5% 7%
32.08 32.74 33.18 33.63
53.76 54.83 55.55 56.26
66.16 67.48 68.37 69.25
72.9 74.37 75.34 76.32
In this paper, a data questionnaire of a set of sustainable construction methods with the possibility of using them in green buildings in Tehran is presented in accordance with the information stated in Section 6. It was found to be economical to use sustainable construction methods in green buildings in Tehran; in addition to the 30 % initial investment (assuming a profit at the time of sale or buyer profits from their investment in buying property), the internal rate of return IRR had a 41.2e77.4 % increase in construction costs and costs of operation, including energy, water and maintenance, and this rate varied inversely with the increase in green characteristics. In other words, as the building increased in terms of the level of LEED certification, the IRR decreased from 77.4 % to 4.2 %. Additionally, increasing energy costs affect the IRR; by increasing energy costs, the internal rate of return increases by 23.0 %. With regard to the interests of the environment and human health, green construction finance officials also recommended further work in the field of infrastructure and culture for sustainability by applying stricter rules and expanding loans and discounts for green buildings to contribute their development. In addition, due to positive internal rate of return observed from the reduced energy consumption, increasing energy prices close to the world rate are reasonable and will substantially help the government. This benefit may help finance infrastructure or provide loans and discounts to green buildings. According to the methods presented, the approach to implementing sustainable green buildings in Tehran is proposed and the rate of return is calculated. It is suggested that residents deciding to buy a building pay greater attention to the financial interests of health and welfare for green buildings compared to conventional buildings. According to the research data and results, the following is suggested for future research: The legal feasibility of using sustainable building methods in Iran; Comparison of sustainable economic construction under the LEED green buildings and non-LEED buildings in Iran; The technical, economic and legal feasibility of using LEED standards in Iran; Investigating the economic benefits of the stabilization and increased energy cost savings as a result of the development of green buildings.
Uncited reference [11].
With increasing energy costs, the internal rate of return is still positive and acceptable in all four scenarios, with low slopes that show identical increases. This rate of increase is less than that in each of the four cases in which the consumer does not make much appeal, but will have many resources at the country level. Table 4 Changes IRR scenarios to increase the cost of energy. Energy cost increase
First scenario
Second scenario
Third scenario
Forth scenario
0% 3% 5% 7%
4.77% 4.87% 4.94% 5%
4% 4.08% 4.13% 4.19%
2.81% 2.87% 2.91% 2.94%
2.41% 2.46 2.49% 2.52%
References English resources [1] H.H. Ali, S.F. Al Nsairat, Developing a green building assessment tool for developing countries-case of Jordan, Build. Environ. 44 (5) (2009) 1053e1064. [2] BREEAM, Building Research Establishment Environment Assessment Method, 1990. [3] Y. Chen, G.E. Okudan, D.R. Riley, Sustainable performance criteria for construction method selection in concrete buildings, Automation Constr. 19 (2) (2010) 235e244. [4] R. Fedrizzi, j. Karistrom, k Brown, The Business Case for Green Building: Word Green Building Council, 2013. [5] B.-G. Hwang, W.J. Ng, Project management knowledge and skills for green construction: overcoming challenges, Int. J. Proj. Manag. 31 (2) (2013) 272e284.
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M. Nazari, R. Mehdi / Pacific Science Review A: Natural Science and Engineering xxx (2016) 1e5 [6] B.G. Hwang, J.S. Tan, Green building project management: obstacles and solutions for sustainable development, Sustain. Dev. 20 (5) (2012) 335e349. [7] E. Tagaza, J. Wilson, Green buildings: drivers and barriers e lessons learned from five melbourne developments, in: Report Prepared for Building Commission by University of Melbourne and Business Outlook and Evaluation, 2004. [8] USGBC. From http://www.usgbc.org/leed. [9] X. Zhang, L. Shen, Y. Wu, Green strategy for gaining competitive advantage in housing development: a China study, J. Clean. Prod. 19 (2) (2011) 157e167.
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Persian references [10] Ghaemi, (1391) reportStudy the Design and Construction of Green Buildings Based on the Identification and Assessment of Structural Stability Performance Criteria in Iran, Tehran University, (Masters). [11] Erabi (1394) Analyze and Evaluate the Technical and Economic Challenges in the Application of Intelligent Building Management Systems in the Approach to Optimize Energy Consumption, Islamic Azad University of Karaj, MA.
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