Green Residential Buildings in Hunan Province Province As a Central-South Region Where Economic Development Grew Relatively Slow

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Energy Procedia 00 (2017) 000–000 Energy Procedia 00 (2017) 000–000 AvailableAvailable onlineScienceDirect online at at www.sciencedirect.com www.sciencedirect.com www.elsevier.com/locate/procedia ScienceDirect www.elsevier.com/locate/procedia 2 Xu et al. / Energy Procedia 00 (2017) 000–000 ScienceDirectScienceDirect 1. Introduction

EnergyEnergy Procedia Procedia 12100 (20(2017)17) 000150–157–000 Implementation of ESFGB has been officially launched in China since 2008 and great achievements have been www.elsevier.com/locate/procedia made through 8 years of development of GBL. By the end of 2015, 3979 GBL schemes were certificated and the Improving Residential Energy Efficiency International Conference, IREE 2017 overall floorage reached to 460 million square meters [1]. GBL scheme can be divided in to two different building InternationalImproving Residential Conference Energy on Improving Efficiency Residential International Energy Conference, Efficiency, IREE IREE 2017 2017 types and two different appraisal stages. One building type is GBL Public Building Scheme (GBLPBS) and the Study on developing status and appropriate technologies analysis of other is GBL Residential Building Scheme (GBLRBS). One appraisal stage is GBL Design Stage (GBLDS) and the Study on developing status and appropriate technologies analysis of other is GBL Operation Stage (GBLOS). Certificated GBL scheme can be divided into 3 star levels, i.e. one-star, greenThe 15th residential International Symposium buildings on inDistrict Hunan Heating Province and Cooling two-star and three-star which is the highest level [2]. Green buildings were developed relatively late in Hunan green residential buildings in Hunan Province Province as a central-south region where economic development grew relatively slow. But green buildings have been developed rapidly with the government’s attention and promotion since 2012. Evaluation Standard for Green Feng Xua,*, Na Xiea, Jin Zhoub, Kunlun Yinc, Baijun Wangd AssessingFeng Xuthea,*, feasibility Na Xiea, Jin Zhouof usingb, Kunlun the Yin heatc, Baijun demand Wang-outdoord Building in Hunan Province (ESFGBHP) was formulated first in 2009 and 126 GBL schemes were certificated in aSchool of Architecture, Hunan University, Changsha, Hunan 410082, China Hunan Province with floorage of 13.33 million square meters by the end of 2015 [3]. temperature functionbCollegeaSchool of ofCivil Architecture, Engineering,for a Hunan long Hunan Uni University,versity,-term Changsha, Changsha, district Hunan Hunan 410082, heat 410082, China Chinademand forecast According to statistical data, 81 schemes of Hunan Province, including 47 GBLPBSs with floorage of 3.13 cArchitecturalbCollege of Civil Design Engineering, Institute ofHunan Hunan University, Province, Changsha, Changsha, Hunan Hunan 410082, 410011, China China million square meters and 34 GBLRBSs with floorage of 6.31 million square meters passed the appraisal of GBL in a,b,ccArchitecturaldHunan Design Greena Institute Building of Council,Hunana Pr Changsha,ovince, Changsha, Hunanb 410007, Hunan China410011, Chinac c I. Andrić *, A.d Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre the past five years. Although the number of public schemes is much more than that of residential schemes, the Hunan Green Building Council, Changsha, Hunan 410007, China overall floorage of residential schemes is over two times than that of public buildings. a IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal Residential buildings are a building type that most closely associates with human life. Therefore, the Abstract bVeolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France Abstract cDépartement Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France development of green residential buildings for energy savings, living environment improvement, and environmental pollution reduction is of great significance [4]. For developing countries, green residential buildings should be Green buildings have become an inevitable trend due to the implementation of the Evaluation Standard for Green Building (ESFGB)Green buildings in China. have Because become of itsan geographiinevitablec trendlocation due in to the the central-south implementation region of of th China,e Evaluation Hunan Standardwas developed for Green relatively Building late developed based on the selection of appropriate technologies. The purpose of appropriate technology compared(ESFGB) into China.other moreBecause industrialized of its geographi regionsc location of China. in theHoweve central-southr, with the region local of government's China, Hunan attention was developed and focus, relatively Hunan latehas implementation is to solve comprehensive problems through a positive interaction mechanism for specific object Abstract madecompared enormous to other progress more industrialized and caught up regions rapidl y.of GreenChina. residential However, buildingswith the localgrow government'seven faster than attention green andpublic focus, buildings. Hunan Thehas with the local natural, economic and social environment to obtain the best comprehensive benefit [5]. overallmade enormous floorage progressof residential and caughtbuildings up rapidlis abouty. Greentwo times residential of public buildings buildings grow among even thesefaster Greenthan green Building public Labelling buildings. (GBL) The Due to the limitations from technology, material and cost, the research and implementation of green residential District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the schemesoverall floorage in the past of fiveresidential years. Inbuildings this paper, is about34 GBL two reside timesntial of buildingpublic buildings schemes amongof Hunan these Province Green wereBuilding analyzed Labelling through (GBL) data buildings are relatively slow in China. However, in most green building technology research, technology is greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat analyticsschemes inincluding the past quantityfive years. and In floorage,this paper, star 34 levelGBL proportionresidential buildingand geographical schemes ofdistri Hunanbution Pr ovinceto reveal were the analyzed developing through status data of considered separately. Boeck et al. [6] provided an updated review of improving energy performance of residential sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, analyticsgreen residential including buildings. quantity Meanwhile,and floorage, tec starhnologies level proportion used in these and geographicalschemes were distri dividedbution into to fivereveal categories the developing including status Land of prolonging the investment return period. buildings. Zhang [7] analyzed the measures of land saving being used in green residential buildings. Chai [8] studied Saving,green residential Energy Saving, buildings. Water Meanwhile, Saving, Materialtechnologies Saving used and in Indoorthese schemesEnvironment were indi videdaccordance into five with categories Evaluation including Standard Land for The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand the comprehensive benefit in full life cycle and incremental cost of water conservation in green buildings. Mohamed GreenSaving, Building Energy inSaving, Hunan Water Province Saving, (ESFGBHP). Material ThenSaving the and technolo Indoorgy Environmentusing frequency in accordanceof GBL resi dentialwith Evaluation schemes wereStandard counted for forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 Ibrahim [9] studied the financial and environmental returns attained by recycling construction waste from selected andGreen sorted Building by different in Hunan categorie Provinces and (ESFGBHP). star levels. Then Combined the technolo with specificgy using technology frequency ofcost, GBL the resi relationshipdential schemes between were frequently counted- buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district projects which conform to the U.S. Green Building Council standards. Al horr [10] established the links between usedand sorted technologies by different and incr categorieementals andcost starof different levels. Combined categories withand starspecific levels technology were discussed. cost, the relationship between frequently- renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were IEQs and occupant well-being and comfort. Nevertheless, appropriate technologies are rarely studied as a whole in used© 2017 technologies The Authors. and Published incremental by costElsevier of different B.V. categories and star levels were discussed. compared with results from a dynamic heat demand model, previously developed and validated by the authors. ©Peer-review 2017 The Authors.under the Published responsibility by Elsevier of the scientific B.V. committee of Improving Residential Energy Efficiency International green buildings, especially with incremental cost. © 2017 The Authors. Published by Elsevier Ltd. Peer-reviewThe results undershowed the that responsibility when only ofweather the scientific change committeeis considered, of Improving the margin Reside of errorntial could Energy be Efficiencyacceptable Internationalfor some applications The aim of this study is to demonstrate the developing status of GBLRBS in Hunan and the inner-relationship Conference,Peer-review under IREE responsibility 2017. of the scientific committee of the International Conference on Improving Residential Energy Efficiency. Conference,(the error in IREE annual 2017. demand was lower than 20% for all weather scenarios considered). However, after introducing renovation between the frequently-used technologies and incremental cost by analyzing all GBLRBSs in the past five years. Keywords:scenarios, Green the errorResidential value Building; increased Developing up to 59.5% Status; (depending Appropriate on Technologies; the weather Hunan and renovationProvince scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the Keywords: Green Residential Building; Developing Status; Appropriate Technologies; Hunan Province 2. Developing status of GBLRBS decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and In this paper, all 34 GBLRBSs of Hunan Province in the past 5 years were analyzed through data analytics improve the accuracy of heat demand estimations. including quantity and floorage, star level proportion and geographical distribution to reveal the developing status of * Corresponding author. Tel.: +86-731-88822634; fax: +86-731-88821912. green residential buildings. * CorrespondingE-mail address: author. [email protected] Tel.: +86-731-88822634; fax: +86-731-88821912. © 2017 The Authors. Published by Elsevier Ltd. E-mail address: [email protected] Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and 2.1. Quantity and floorage 1876-6102 © 2017 The Authors. Published by Elsevier B.V. Cooling. Peer-review1876-6102 © under 2017 theThe responsibility Authors. Published of the sc byientific Elsevier committee B.V. of Improving Residential Energy Efficiency International Conference, IREE Peer-review2017. under the responsibility of the scientific committee of Improving Residential Energy Efficiency International Conference, IREE Table 1. GBLRBS quantity variation (2011-2015). 2017.Keywords: Heat demand; Forecast; Climate change Scheme type 2011 2012 2013 2014 2015 Total

One-star 0 2 3 9 15 29 Two-star 0 2 1 0 1 4 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Three-star 0 0 0 1 0 1 Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. Subtotal 0 4 4 10 16 34 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the International Conference on Improving Residential Energy Efficiency. 10.1016/j.egypro.2017.08.012

10.1016/j.egypro.2017.08.012 1876-6102 Available online at www.sciencedirect.com Available online at www.sciencedirect.com

Energy Procedia 00 (2017) 000–000 Energy Procedia 00 (2017) 000–000 ScienceDirect www.elsevier.com/locate/procedia Feng Xu et al. / Energy Procedia 121 (2017) 150–157 151 ScienceDirect www.elsevier.com/locate/procedia 2 Xu et al. / Energy Procedia 00 (2017) 000–000

1. Introduction

Implementation of ESFGB has been officially launched in China since 2008 and great achievements have been made through 8 years of development of GBL. By the end of 2015, 3979 GBL schemes were certificated and the Improving Residential Energy Efficiency International Conference, IREE 2017 overall floorage reached to 460 million square meters [1]. GBL scheme can be divided in to two different building Improving Residential Energy Efficiency International Conference, IREE 2017 types and two different appraisal stages. One building type is GBL Public Building Scheme (GBLPBS) and the Study on developing status and appropriate technologies analysis of other is GBL Residential Building Scheme (GBLRBS). One appraisal stage is GBL Design Stage (GBLDS) and the Study on developing status and appropriate technologies analysis of other is GBL Operation Stage (GBLOS). Certificated GBL scheme can be divided into 3 star levels, i.e. one-star, green residential buildings in Hunan Province two-star and three-star which is the highest level [2]. Green buildings were developed relatively late in Hunan green residential buildings in Hunan Province Province as a central-south region where economic development grew relatively slow. But green buildings have been developed rapidly with the government’s attention and promotion since 2012. Evaluation Standard for Green Feng Xua,*, Na Xiea, Jin Zhoub, Kunlun Yinc, Baijun Wangd Feng Xua,*, Na Xiea, Jin Zhoub, Kunlun Yinc, Baijun Wangd Building in Hunan Province (ESFGBHP) was formulated first in 2009 and 126 GBL schemes were certificated in aSchool of Architecture, Hunan University, Changsha, Hunan 410082, China Hunan Province with floorage of 13.33 million square meters by the end of 2015 [3]. bCollegeaSchool of ofCivil Architecture, Engineering, Hunan Hunan Uni University,versity, Changsha, Changsha, Hunan Hunan 410082, 410082, China China According to statistical data, 81 schemes of Hunan Province, including 47 GBLPBSs with floorage of 3.13 cArchitecturalbCollege of Civil Design Engineering, Institute ofHunan Hunan University, Province, Changsha, Changsha, Hunan Hunan 410082, 410011, China China million square meters and 34 GBLRBSs with floorage of 6.31 million square meters passed the appraisal of GBL in cArchitecturaldHunan Design Green Institute Building of Council,Hunan Pr Changsha,ovince, Changsha, Hunan 410007, Hunan China410011, China d the past five years. Although the number of public schemes is much more than that of residential schemes, the Hunan Green Building Council, Changsha, Hunan 410007, China overall floorage of residential schemes is over two times than that of public buildings. Residential buildings are a building type that most closely associates with human life. Therefore, the Abstract Abstract development of green residential buildings for energy savings, living environment improvement, and environmental pollution reduction is of great significance [4]. For developing countries, green residential buildings should be Green buildings have become an inevitable trend due to the implementation of the Evaluation Standard for Green Building (ESFGB)Green buildings in China. have Because become of itsan geographiinevitablec trendlocation due in to the the central-south implementation region of of th China,e Evaluation Hunan Standardwas developed for Green relatively Building late developed based on the selection of appropriate technologies. The purpose of appropriate technology compared(ESFGB) into China.other moreBecause industrialized of its geographi regionsc location of China. in theHoweve central-southr, with the region local of government's China, Hunan attention was developed and focus, relatively Hunan latehas implementation is to solve comprehensive problems through a positive interaction mechanism for specific object madecompared enormous to other progress more industrialized and caught up regions rapidl y.of GreenChina. residential However, buildingswith the localgrow government'seven faster than attention green andpublic focus, buildings. Hunan Thehas with the local natural, economic and social environment to obtain the best comprehensive benefit [5]. overallmade enormous floorage progressof residential and caughtbuildings up rapidlis abouty. Greentwo times residential of public buildings buildings grow among even thesefaster Greenthan green Building public Labelling buildings. (GBL) The Due to the limitations from technology, material and cost, the research and implementation of green residential schemesoverall floorage in the past of fiveresidential years. Inbuildings this paper, is about34 GBL two reside timesntial of buildingpublic buildings schemes amongof Hunan these Province Green wereBuilding analyzed Labelling through (GBL) data buildings are relatively slow in China. However, in most green building technology research, technology is analyticsschemes inincluding the past quantityfive years. and In floorage,this paper, star 34 levelGBL proportionresidential buildingand geographical schemes ofdistri Hunanbution Pr ovinceto reveal were the analyzed developing through status data of considered separately. Boeck et al. [6] provided an updated review of improving energy performance of residential analyticsgreen residential including buildings. quantity Meanwhile,and floorage, tec starhnologies level proportion used in these and geographicalschemes were distri dividedbution into to fivereveal categories the developing including status Land of buildings. Zhang [7] analyzed the measures of land saving being used in green residential buildings. Chai [8] studied Saving,green residential Energy Saving, buildings. Water Meanwhile, Saving, Materialtechnologies Saving used and in Indoorthese schemesEnvironment were indi videdaccordance into five with categories Evaluation including Standard Land for the comprehensive benefit in full life cycle and incremental cost of water conservation in green buildings. Mohamed Saving, Energy Saving, Water Saving, Material Saving and Indoor Environment in accordance with Evaluation Standard for Green Building in Hunan Province (ESFGBHP). Then the technology using frequency of GBL residential schemes were counted Ibrahim [9] studied the financial and environmental returns attained by recycling construction waste from selected Green Building in Hunan Province (ESFGBHP). Then the technology using frequency of GBL residential schemes were counted and sorted by different categories and star levels. Combined with specific technology cost, the relationship between frequently- projects which conform to the U.S. Green Building Council standards. Al horr [10] established the links between usedand sorted technologies by different and incr categorieementals andcost starof different levels. Combined categories withand starspecific levels technology were discussed. cost, the relationship between frequently- IEQs and occupant well-being and comfort. Nevertheless, appropriate technologies are rarely studied as a whole in ©used 2017 technologies The Authors. and Published incremental by costElsevier of different B.V. categories and star levels were discussed. Peer-review© 2017 The Authors.under the Published responsibility by Elsevier of the scientific B.V. committee of Improving Residential Energy Efficiency International green buildings, especially with incremental cost. Conference,Peer-review underIREE 2017.the responsibility of the scientific committee of Improving Residential Energy Efficiency International The aim of this study is to demonstrate the developing status of GBLRBS in Hunan and the inner-relationship Conference, IREE 2017. between the frequently-used technologies and incremental cost by analyzing all GBLRBSs in the past five years. Keywords: Green Residential Building; Developing Status; Appropriate Technologies; Hunan Province Keywords: Green Residential Building; Developing Status; Appropriate Technologies; Hunan Province 2. Developing status of GBLRBS

In this paper, all 34 GBLRBSs of Hunan Province in the past 5 years were analyzed through data analytics including quantity and floorage, star level proportion and geographical distribution to reveal the developing status of * Corresponding author. Tel.: +86-731-88822634; fax: +86-731-88821912. green residential buildings. * CorrespondingE-mail address: author. [email protected] Tel.: +86-731-88822634; fax: +86-731-88821912. E-mail address: [email protected] 2.1. Quantity and floorage 1876-6102 © 2017 The Authors. Published by Elsevier B.V. Peer-review1876-6102 © under 2017 theThe responsibility Authors. Published of the sc byientific Elsevier committee B.V. of Improving Residential Energy Efficiency International Conference, IREE Peer-review2017. under the responsibility of the scientific committee of Improving Residential Energy Efficiency International Conference, IREE Table 1. GBLRBS quantity variation (2011-2015). 2017. Scheme type 2011 2012 2013 2014 2015 Total

One-star 0 2 3 9 15 29 Two-star 0 2 1 0 1 4 Three-star 0 0 0 1 0 1 Subtotal 0 4 4 10 16 34 Xu et al. / Energy Procedia 00 (2017) 000–000 3 152 Feng Xu et al. / Energy Procedia 121 (2017) 150–157 4 Xu et al. / Energy Procedia 00 (2017) 000–000

Due to higher requirements of design and construction, the number of GBLRBS is only in a small amount in the for the construction phase but also need more effort at the design phase. Most developers are reluctant to pursue first three years. Nevertheless, GBL residence schemes achieved a breakthrough since 2012 and the number of two-star GBLRBSs which require a longer construction period and even a greater investment risk. GBLRBS grew rapidly in 2014 and 2015 (Table 1). Along with the implementation of the 2nd edition of ESFGBHP in 2017, it can be estimated that the quantity of GBL residential schemes in Hunan Province will grow significantly 2.3. Geographical distribution in the near future.

Table 2. GBLRBS floorage index (2011-2015). 20 18 35 31 Index 2011 2012 2013 2014 2015 30 15 Scheme quantity - 4 4 10 16 25

Building quantity - 23 40 85 146 20 10 2 Scheme quantity Scheme Overall floorage (m ) - 751500 676600 1168300 3710300 6 quantity Scheme 15 Floorage per scheme (m2) - 187900 169200 116800 231900 5 10 2 3 Floorage per building (m ) - 32700 16900 13700 25400 111 1 5 1 1 1 0 0 As shown in Table 2, from 2012 to 2015, GBLRBSs in Hunan Province grew rapidly not only in the scheme Yuelu Tianxin Wangcheng Yuhua Furong Kaifu Changsha Changsha Zhuzhou Shaoyang Yongzhou County quantity and building quantity but also in overall floorage. Compared with 2012, the overall floorage increased Geographical Distribution Regional Distribution fourfold in 2015. This showed that the development of green residential buildings in Hunan Province has grown tremendously. In terms of the floorage per building, the average floorage per building reached 21400 m2. This Fig. 3. Geographical Distribution, Hunan Province (2011-2015). Fig. 4. Regional Distribution, Changsha (2011-2015). illustrates that most single buildings in GBLRBSs are large scale apartments or high-rise buildings. The number of the scheme quantity is relatively small. However, considering that residential scheme has As shown in Fig. 3, the regional development of green residential buildings in Hunan Province was extremely completely different characteristics with that of the public scheme, the actual floorage of GBLRBS is sufficient. uneven. There are 13 prefecture-level cities and 1 autonomous prefecture in Hunan Province. Nevertheless, over Unlike public buildings, most GBLRBSs are large-scale residential districts. Through calculation, it can be found 90% of the certificated GBLRBSs are located in Changsha which is the capital city of Hunan Province. However, that average floorage per residential scheme is about 193,000 m2 thus the average floorage per public scheme is only 2 the development in other prefecture-level cities was falling behind. This indicated that the number of certificated 66,000 m . The value is almost three times than that of the public scheme. GBLRBS is closely related to the level of the local economic development, in which the higher the level of local economic income, the more the GBLRBS number. 2.2. Star level proportion As shown in Fig. 4, the regional distribution of GBLRBSs in Changsha was also uneven. GBLRBSs were mostly concentrated in Yuelu District, Tianxin District and Wangcheng District, with the number of 18, 6, and 3,

☆ ☆☆ ☆☆☆ 100 respectively. Meixihu International Park was approved as one of the first national "Green Ecological Demonstration 6 10 90 ☆☆☆ City". In 2012, the rate of green buildings within the demonstration area is at 100%. Meanwhile, the national 85% (29) 25 80 Xiangjiang New District was officially approved by the state council for establishment in Hunan Province in 2015 ☆☆ 50 70 (Xiangjiang New district is located in the west bank of Xiangjiang River in Changsha, including Yuelu District, ☆ 60 Wangcheng District and partial Ningxiang County). This leads to the development of green residential buildings to

50 be a key focus. 90 94 40 75 Percentage Percentage (in %) 30 3. Technologies applied to GBLRBS 50 20 This paper collected the detailed technical application data of 34 GBLRBSs in Hunan Province. The statistical 10 Nil framework was classified in five categories according to the ESFGBHP, i.e. Land Saving, Energy Saving, Water 12% (4) 0 3% (1) 2011 2012 2013 2014 2015 Saving, Material Saving and Indoor Environment. The category of Operation and Management was not considered Year in the statistics due to the fact that there is no GBLOS residential scheme in Hunan Province yet. Every technology Fig. 1. Star Level Distribution Diagram. Fig. 2. GBLRBS Star Level Proportion (2011-2015). used by GBLRBSs was collected separately and their frequency usage was counted respectively. According to statistics, there were 35 specific technologies in five categories in total, including 7 specific The total number of one-star, two-star and three-star GBLRBSs in Hunan Province is 29, 4, and 1 by the end of technologies applied in Land Saving category such as underground parking, permeable ground and multi-layer 2015. Among which, one-star GBLRBS accounted for the largest proportion of 85%, two-star and three-star greening, 9 specific technologies in Energy Saving category such as green lighting, cross-ventilation and windows GBLRBSs accounted for 12% and 3%, respectively (Fig. 1). air tightness, 6 specific technologies in Water Saving category, 5 specific technologies in Material Saving category As shown in Fig. 2, the proportion of two-star GBLRBSs declined gradually. This is because the goal of one-star and 8 specific technologies in Indoor Environment category. scheme can be easily achieved with a lower cost. However, two-star GBLRBSs not only require more investment Xu et al. / Energy Procedia 00 (2017) 000–000 3 Feng Xu et al. / Energy Procedia 121 (2017) 150–157 153 4 Xu et al. / Energy Procedia 00 (2017) 000–000

Table 2. GBLRBS floorage index (2011-2015). 20 18 35 31 Index 2011 2012 2013 2014 2015 30 15 Scheme quantity - 4 4 10 16 25

50 be a key focus. 90 94 40 75 Percentage Percentage (in %) 30 3. Technologies applied to GBLRBS 50 20 This paper collected the detailed technical application data of 34 GBLRBSs in Hunan Province. The statistical 10 Nil framework was classified in five categories according to the ESFGBHP, i.e. Land Saving, Energy Saving, Water 12% (4) 0 3% (1) 2011 2012 2013 2014 2015 Saving, Material Saving and Indoor Environment. The category of Operation and Management was not considered Year in the statistics due to the fact that there is no GBLOS residential scheme in Hunan Province yet. Every technology Fig. 1. Star Level Distribution Diagram. Fig. 2. GBLRBS Star Level Proportion (2011-2015). used by GBLRBSs was collected separately and their frequency usage was counted respectively. According to statistics, there were 35 specific technologies in five categories in total, including 7 specific The total number of one-star, two-star and three-star GBLRBSs in Hunan Province is 29, 4, and 1 by the end of technologies applied in Land Saving category such as underground parking, permeable ground and multi-layer 2015. Among which, one-star GBLRBS accounted for the largest proportion of 85%, two-star and three-star greening, 9 specific technologies in Energy Saving category such as green lighting, cross-ventilation and windows GBLRBSs accounted for 12% and 3%, respectively (Fig. 1). air tightness, 6 specific technologies in Water Saving category, 5 specific technologies in Material Saving category As shown in Fig. 2, the proportion of two-star GBLRBSs declined gradually. This is because the goal of one-star and 8 specific technologies in Indoor Environment category. scheme can be easily achieved with a lower cost. However, two-star GBLRBSs not only require more investment 154 Feng Xu et al. / Energy Procedia 121 (2017) 150–157 Xu et al. / Energy Procedia 00 (2017) 000–000 5 6 Xu et al. / Energy Procedia 00 (2017) 000–000

3.1. Top 10 Technologies Fig. 6 shows the frequency of different technologies being used in the above mentioned five categories. . Three to four technologies are being utilized frequently in each category. For example, in the category of Land saving, Statistics showed that most frequently used technologies in GBLRBSs in Hunan Province are high-performance underground parking, permeable ground and multi-layer greening technologies were mostly used. This is mainly steel, household metering, water-saving appliances, open space, underground parking, sprinkler irrigation, air because these technologies have a lower cost with a better effect. Meanwhile, a significant proportion of these tightness window, conducive to cross-ventilation, green lighting and natural ventilation and lighting. 3 technologies technologies are passive technologies that can be implemented through elaborate design with a near-zero cost. were used in all schemes and nearly half of these technologies are passive technologies that only require good Furthermore, less used technologies are often expensive. For instance, solar water-heating systems, ground source design with almost no extra cost such as conducive to cross-ventilation, natural ventilation and lighting. All other heat pumps (GSHPs), adjustable shading, etc. are expensive technologies rarely used in GBLRBS. technologies are mature and low-cost, such as water-saving appliances and household metering (Fig. 5). 3.3. Incremental Cost 100.00 100.00 100.00 100% 97.05 97.05 97.05 97.05 97.05 97.05 97.05 Increment cost of green buildings is defined as the cost increase of the construction project caused by design and construction processes in accordance with the demand of ESFGB. Since incremental cost is an important factor 90% affecting the choice of technologies, it has been statistically analyzed within 34 GBLRBSs. Based on the above definition, the incremental cost of green buildings should include green building consulting cost, certification cost Percentage of Use (in %) 80% and green building technology incremental cost. This paper focuses on the incremental cost of green building technology measurement. First of all, incremental cost per unit area was calculated and counted respectively in accordance with different star levels of GBLRBS. As shown in Table 3, the average incremental cost of one-star scheme was 8.47 Yuan / m2, the average incremental cost of two-star scheme was 39.58 Yuan / m2 and the average incremental cost of three-star scheme was 201.3 Yuan / m2. From the viewpoint of the proportion of incremental cost in the construction cost, the incremental cost of one-star scheme accounted for only 0.57% of construction cost, while the incremental cost of Fig. 5. Top 10 Technologies used in 34 GBLRBSs in Hunan Province. three-star scheme accounted for over 10% of construction cost which cannot be ignored.

3.2. Technical application using frequency Table 3. Incremental cost of GBLRBS.

One-star Two-star Three-star

3.2. Technical application using frequency Table 3. Incremental cost of GBLRBS.

One-star Two-star Three-star

Underground parking 97.05 Average incremental cost per unit area (Yuan/m2) 8.47 39.58 201.3 Permeable ground 94.12 Multi-layer greening 94.12 Average construction cost per unit area (Yuan/m2) 1480 1520 1980 Habitat wind environment 94.12 Bottom overhead 26.47 Proportion of incremental cost in the construction cost (%) 0.57% 2.60% 10.17% Green roofs 14.71 Green lighting 97.05 Conducive to cross-ventilation 97.05 Indoor Window air tightness 97.05 Land Saving Material Indoor Land Material Environmen Temperature control 94.12 16.90% Saving Environment Saving Saving t Ventilation layer insulation roofs 61.76 0.00% 10.86% 12.31% Concentrated air conditioning 14.71 0.00% 7.45% Ground source heat pump 8.82 Solar water-heating system 8.82 Water Shading 2.94 Saving 24.22% Water-saving appliances 100 Energy Household metering 100 Water Energy Saving Sprinkler irrigation 97.05 Saving Saving 52.61% Rain water reuse 64.71 46.56% 29.09% Reclaimed water reuse 32.35 High-performance steel 100 Recyclable material 91.18 Saving Water Saving Energy Saving Land Saving Material Integrated decoration 23.53 Open space 97.05 Natural ventilation and lighting 97.05 Fair visibility 91.18 Fig. 7. Incremental cost proportion in five categories (a) one-star level (b) two-star level. Light tube 11.76 Ventilation device 5.82 Air monitor 2.94 Then the proportion of incremental cost of each category was calculated and counted respectively in accordance Descented garden 2.94 Indoor Environment Adjustable shading 2.94 with different star levels of GBLRBS. As shown in Fig. 7, in the five categories of technologies, the largest 0 10 20 30 40 50 60 70 80 90 100 incremental cost was on Water Saving and followed by Energy Saving in one-star scheme, while the largest incremental cost was on Energy Saving, followed by Water Saving in the two-star scheme. In five categories of Percentage of using frequency（in %） technologies, Energy Saving technology accounted a larger proportion, which is due to the largest amount in such category, and its effect on improving living comfort is more obvious. The reason that Water Saving was used in the Fig. 6. Technical application frequency usage statistics of 34 GBLRBSs in Hunan Province. largest proportion in one-star scheme is mainly due to abundant rainfall in Hunan Province and Water Saving 156 Feng Xu et al. / Energy Procedia 121 (2017) 150–157 Xu et al. / Energy Procedia 00 (2017) 000–000 7 8 Xu et al. / Energy Procedia 00 (2017) 000–000 technologies were vigorously promoted. In addition, rain water reuse and reclaimed water reuse costs are relatively 5. Conclusion high. This study analyzed the developing status of GBLRBS in Hunan Province and the inner-relationship between 4. Discussion frequently-used technologies and incremental cost by analyzing 34 GBLRBSs. The main conclusions are drawn as follows: Appropriate technology, also known as "suitable technology," was first proposed by Atkinson and Stilts, the 1) Although the GBLRBS developed rapidly, GBLOS was ignored compared with GBLDS. This showed that Nobel Prize winners in economics. The original intention was "localized learning by doing" which means localized the implementation of GBLRBS is still in its initial stage in Hunan Province. learning by doing. This indicated that developing countries and regions should not blindly copy and imitate the 2) GBLRBS developed uneven in different regions due to the unbalanced development in economy. Most technologies that have been used by the developed countries, but they should explore a road suitable for their own GBLRBSs existed in Changsha. This means that GBLRBS should be popularized in other regions. conditions and development [11]. The characteristics of appropriate technology should include the popularization, 3) GBLRBS and GBLPBS are very different. Public buildings can be built as a demonstration but residential effectiveness, economy, locality, and dynamics. buildings must be sold. Thus technology selection is influenced by the incremental cost. According to the First of all, specific technologies were divided into three types. The first type is low-cost technology, price ranges proportion of incremental cost in the construction cost of different star schemes, one and two-star scheme from 0-50 (Yuan / m2). The second category is medium technology, price ranges from 50-200 (Yuan / m2). The third could easily be popularized. Most frequently used technologies are high-performance steel, household category is expensive technology, price exceeds 200 (Yuan / m2). According to the statistics of the incremental cost metering, water-saving appliances, open space, underground parking, sprinkler irrigation, air tightness per unit area of 35 specific technologies, 26 specific technologies belong to the low-price technology, 5 specific window, conducive to cross-ventilation, green lighting and natural ventilation and lighting. technologies belong to the medium technology and 4 specific technologies belong to the expensive technology. 4) Incremental cost is an important factor not only in technology selection but also in determining whether a specific technology is an appropriate technology or not. In the stage of pre-design of technology selection for 30 ☆ ☆☆ ☆☆☆ 100% ☆ ☆☆ ☆☆☆ green residential buildings, passive technologies with low-cost should be considered with priority, active 26 25 73.08% 75.00% technologies should be used for optimization. Nevertheless, renewable energy technologies should be given 80% 70.19% 19.00 60.00% more consideration both in the design process and the practical application process, although their cost is 20 18.25 60.34% 15.69 60% 55.00% relatively expensive. 15 40% 10 28.97% Acknowledgements

in different type (in %) (in type different in 18.75% used in different type type used in different 5 4 20% 5 Percentage of using frequency 2.75 3.00 3.00 8.62% Average quantity of technologies 1.45 0.34 0.75 This work is financially supported by the 12th Five Year National R&D Support Program of China (No. 0 0% 0-50 50-200 Exceeding 200 0-50 50-200 Exceeding 200 2014BAL06B01) and the New Urbanization Guidance Fund Program of Hunan Province, China, 2016 (Project Incremental cost（ Yuan/ m2） Incremental cost（ Yuan/ m2） Title: Research on Key Technologies and Projects of Green Building in Hunan Province).

Fig. 8. Average quantity of technologies used in different types, Fig. 9. Technology frequency usage in different types. References

In general, most popular technologies can be seen as appropriate technologies. This is because the actual utility of [1] Chinese society for urban studies. Chinese green building 2016. Beijing: China architecture & building press; 2016. (In Chinese) the popular technologies has been verified after a sequence of testing. Meanwhile, the choice of technology is [2] Ministry of housing and urban-rural development. Evaluation Standard for Green Building (GB/T 50378-2006). Beijing: China Architecture closely related to the incremental cost. The lower the incremental cost of the specific technology, the higher the & Building Press; 2006. (In Chinese) frequency of usage. [3] Hunan Green Building Council. Green building development in Hunan Province. Changsha: 2016. (In Chinese) [4] Yan Tan. A study on the appropriate technology of eco-residential community. Master thesis. Tianjin: Tianjin University; 2003. (In Chinese) According to Fig. 8 and Fig. 9, from the average quantity of view, the low-cost technologies were mostly used [5] Xiaoyang Chen. The theoretic construction of contemporary appropriate technology concept. New architecture 2005; 6:69-72. (In Chinese) not only in one-star scheme but also in two-star and three-star schemes. Average quantity of technologies of low- [6] L. De Boeck, S. Verbeke, A. Audenaert, L. De Mesmaeker. Improving the energy performance of residential buildings: A literature review. cost technologies was 6-7 times more than that of medium technologies and expensive technologies. Nevertheless, Renew Sust Energ Rev 2015; 52:960-975. frequency usage in different types of technologies is rather different. Technology frequency usage declined [7] Xiaobei Zhang. A study on strategy of land-saving in green residence building-based on evaluation standard for green building. Master thesis. obviously along with the cost increase in one-star and two schemes while frequency usage remained unchanged in Taiyuan: Taiyuan University of technology; 2013. (In Chinese) [8] Hongxiang Chai. Study on technology and economy of water-saving about green building community. Ph.D thesis. Chongqing: Chongqing three-star scheme. Furthermore, technology selection of one-star, two-star and three-star schemes is slightly University; 2008. (In Chinese) different. One-star scheme inclines to choose low-cost technologies especially passive technologies. Two and three- [9] Mohamed Ibrahim. Estimating the sustainability returns of recycling construction waste from building projects. Sustainable Cities and Society star schemes also choose low-cost technologies but also select some expensive technologies such as GSHP and (SCS) 2016; 23:78-93. reclaimed water reuse. The reason is that the technical demands for two and three-star schemes are much higher than [10] Yousef Al horr, Mohammed Arif, Ahmed Mazroei, Amit Kaushik, Esam Elsarrag. Impact of indoor environmental quality on occupant well- that of one-star scheme. Medium cost or even expensive technologies must be used to satisfy the requirements of being and comfort: A review of the literature. International Journal of Sustainable Built Environment 2016; 5:1-11. [11] Jie Yu. Appropriate technology and localization of green design. Master thesis. Hefei: Hefei University of technology; 2005. (In Chinese) evaluation. In addition, there still exists the phenomenon that a small amount of relatively expensive technologies are widely used. This is because these technologies are corresponding with local natural climate conditions. For instance, there is an abundance of rainfall in Hunan Province and residential buildings consume more water than public building, thus rain water reuse technology is frequently used. Feng Xu et al. / Energy Procedia 121 (2017) 150–157 157 Xu et al. / Energy Procedia 00 (2017) 000–000 7 8 Xu et al. / Energy Procedia 00 (2017) 000–000 technologies were vigorously promoted. In addition, rain water reuse and reclaimed water reuse costs are relatively 5. Conclusion high. This study analyzed the developing status of GBLRBS in Hunan Province and the inner-relationship between 4. Discussion frequently-used technologies and incremental cost by analyzing 34 GBLRBSs. The main conclusions are drawn as follows: Appropriate technology, also known as "suitable technology," was first proposed by Atkinson and Stilts, the 1) Although the GBLRBS developed rapidly, GBLOS was ignored compared with GBLDS. This showed that Nobel Prize winners in economics. The original intention was "localized learning by doing" which means localized the implementation of GBLRBS is still in its initial stage in Hunan Province. learning by doing. This indicated that developing countries and regions should not blindly copy and imitate the 2) GBLRBS developed uneven in different regions due to the unbalanced development in economy. Most technologies that have been used by the developed countries, but they should explore a road suitable for their own GBLRBSs existed in Changsha. This means that GBLRBS should be popularized in other regions. conditions and development [11]. The characteristics of appropriate technology should include the popularization, 3) GBLRBS and GBLPBS are very different. Public buildings can be built as a demonstration but residential effectiveness, economy, locality, and dynamics. buildings must be sold. Thus technology selection is influenced by the incremental cost. According to the First of all, specific technologies were divided into three types. The first type is low-cost technology, price ranges proportion of incremental cost in the construction cost of different star schemes, one and two-star scheme from 0-50 (Yuan / m2). The second category is medium technology, price ranges from 50-200 (Yuan / m2). The third could easily be popularized. Most frequently used technologies are high-performance steel, household category is expensive technology, price exceeds 200 (Yuan / m2). According to the statistics of the incremental cost metering, water-saving appliances, open space, underground parking, sprinkler irrigation, air tightness per unit area of 35 specific technologies, 26 specific technologies belong to the low-price technology, 5 specific window, conducive to cross-ventilation, green lighting and natural ventilation and lighting. technologies belong to the medium technology and 4 specific technologies belong to the expensive technology. 4) Incremental cost is an important factor not only in technology selection but also in determining whether a specific technology is an appropriate technology or not. In the stage of pre-design of technology selection for 30 ☆ ☆☆ ☆☆☆ 100% ☆ ☆☆ ☆☆☆ green residential buildings, passive technologies with low-cost should be considered with priority, active 26 25 73.08% 75.00% technologies should be used for optimization. Nevertheless, renewable energy technologies should be given 80% 70.19% 19.00 60.00% more consideration both in the design process and the practical application process, although their cost is 20 18.25 60.34% 15.69 60% 55.00% relatively expensive. 15 40% 10 28.97% Acknowledgements

Fig. 8. Average quantity of technologies used in different types, Fig. 9. Technology frequency usage in different types. References