2. The Assessment Results Based on BREEAM, LEED, GBTool, and CASBEE

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1 4-14 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) COMPARISON OF THE ASSESSMENT RESULTS OF BREEAM, LEED, GBTOOL AND CASBEE Yukihiro KAWAZU 1 Nobuhiro SHIMADA 2 Noriyoshi YOKOO Dr. Eng 1 Tatsuo OKA Dr. Eng Department of Architecture, Utsunomiya University, Yoto, Utsunomiya, Tochigi , Japan, mt3349@cc.utsunomiya-u.ac.jp yokoo@cc.utsunomiya-u.ac.jp oka@cc.utsunomiya-u.ac.jp Kansai Electric Power, Nakanoshima, Kita-ku, Osaka , Japan, K647997@kepco.co.jp Keywords: Environmental assessment method, BREEAM, LEED, GBTool, CASBEE Summary The assessment results of BREEAM, LEED, GBTool, and CASBEE are compared in this study. The purpose is to confirm the identity and the difference of the assessment methods. Since the beginning of the 199 s, environmental assessment methods have been developed and implemented in many countries to enhance energy conservation buildings, green buildings, and high performances buildings. While these assessment methods are used, the buildings are ranked by the original assessment results of each method. In this study, the assessment results of a high performance building by the four environmental assessment methods of BREEAM, LEED, GBTool, and CASBEE are compared to understand the similarities and the differences of the assessment methods. In addition, to compare the assessment results in detail, three high performance buildings and one low performance building are assessed by the four environmental assessment methods. Thereby, this study specifies the similarities and differences of each assessment method. 1. Introduction The assessment results of BREEAM, LEED, GBTool, and CASBEE are compared in this paper. The purpose of this study is to understand the similarities and the differences of the assessment methods. Since the beginning of the 199 s, architectural environmental assessment methods came to be a focus of attention as there began to be more interest in green and sustainable buildings. The main environmental assessment methods are BREEAM (Building Research Establishment Environmental Assessment Method), which was developed in the U.K in 199, LEED (Leadership in Energy and Environmental Design), which was developed in the U.S.A in 1998, GBTool (Green Building Assessment Tool), which was developed by National Resource Canada and combined 14 countries in 1998 and CASBEE (Comprehenxive Assessment System for Building Environmental Efficiency), which was developed in Japan in 23. In this study, we compared the assessment results of one high performance building by four environmental assessment methods (BREEAM, LEED, GBTool and CASBEE) to understand the similarities and the differences of the assessment methods. In addition, to compare the assessment results in detail, three high performance buildings and one low performance building were assessed by BREEAM, LEED, GBTool and CASBEE. Through this study, the features of each assessment method will be made clear. 2. The Assessment Results Based on BREEAM, LEED, GBTool, and CASBEE In the following, the four high performance buildings and one low performance building are assessed by BREEAM, LEED, GBTool, and CASBEE. 2.1 The Assessment Results of the Same Building Based on BREEAM, LEED, GBTool, and CASBEE One case study building (there after referred to as Building A) is an office building in Kobe city. It was designed based on three concepts, which are safety and reliance, energy conservation, and symbolism

2 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) Fig.1 shows Building A s outline and environmental considerations. Fig.2 shows the assessment results of Building A based on BREEAM, LEED, GBTool, and CASBEE BREEAM The score is high in Health and comfort and Energy and Transport, but is low in Materials and Ecology in the issue categories. In Building A, the cooling tower and the radio tower generate ventilation from wind power and temperature gradients. Building A introduced a monitoring system for efficient operation. The site is conveniently located on road access. These factors affect the high score. A small amount of recycled materials is used in building A. There are few greens on the site. These factors affect the low score LEED The score is good in Sustainable Site (SS), Energy & Atmosphere, (EA) and Indoor Environmental Quality (IEQ), but otherwise the score is low in Materials & Resources (MR). In Building A, the site is located on a developed site. Building A introduced a natural ventilation system. The light fixtures are automatically controlled by brightness sensors. The HVAC system combine comfort with energy conservation. These factors contribute to the high score. In Building A, a little amount of recycled and reused materials are used, but the amount dose not fulfil criteria of LEED. This factor affects the poor score GBTool The score is high in all categories, especially on L (Environmental Loading) and S (Service Quality). The factors are as follows; reducing CO 2 emission by energy saving, using no halon fire retardant and refrigerant of ODP= for reduced atmospheric emission leading to ozone depletion, ample freedom for planning equipment and space, and using a vibration dampening system. parabolic antenna radio tower natural ventilation by the radio tower Management Health and comfort Energy Transport Water Materials Land use Site ecology Pollution solar panel control of the lighting by natural lighting heat reflective pair glass use of underground water for continuous air-conditioning for 24h use of a large difference air conditioning use of no haron fire retardant use of refrigerant of ODP= building thermal mass system Building type Office Location Kobe city, Hyogo prefecture Site area 3349 Total floor area Floors +19,-2 Structure Above the ground S Below the ground RC,SRC Figure 1 Outline of A building Sustainable Sites Building Performance Water Efficiency Total Design & Procurement Assessments Energy & Atomosphere R Resource Consumption Q-1 Indoor Environment L Environmental Loadings Materials & Resource Q-2 Quality Service Management & Operation Assessments 1) BREEAM 2) LEED 3) GBTool LR-3 Off-site Environment LR-2 Resources and Materials 4) CASBEE Q Indoor Environmental Quality Indoor Environment Quality S Service Quality Yes Q-3 Outdoor Environment on Site LR-1 Energy Lost Points Innovation & Design Process Figure 2 The assessment results of Building A No

3 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) CASBEE The score is high in Q-2 Quality of Service, Q-3 Outdoor Environment on Site, and LR-1 Energy, but otherwise the score is low in LR-2 Resources and Materials. In a Building, energy consumption is reduced by a number of energy-saving measures and natural energy utilizations. The floor load margin is 5% higher than the Building Standards Law. There is freedom for planning equipment and space. The exterior as designed in consideration of the surrounding environment. These factors affect the high score.there is a small amaunt of recycled and reused materials used. This factor affects the low score. 2.2 The Assessment Results of the Case Study Buildings on BREEAM, LEED, GBTool, and CASBEE Case Study Buildings In this study, except in the case of building A, we assessed three case study buildings, which are of high performance. These buildings outline is shown in table One Low Performance Building To compare the low assessment results, One low performance building is also assessed. The building s outline is shown in Table The Assessment Results Table 4 shows the assessment results of four case study buildings and one low performance building. In the four case study buildings, the assessment results of BREEAM are EPI = 9, Very Good in Design & Procurement Assessments, and Excellent in Management & Operation Assessment. The assessment results of LEED are Silver or Gold. The assessment results of GBTool are from 2.2 to 2.9. The assessment results of CASBEE are A or S on the building sustainability rating based on BEE (Building Environmental Efficiency). These assessment results are high based on each assessment method. Table 1 Outline of Case Study Buildings A B C D Location Hyogo Tokyo Tokyo Kanagawa Structure Above the ground S,SRC CFT S,SRC :S under the ground :RC SRC Total floor area 33, 16, 9, 8, Completion Floors +19,-2 +37,-4 +1,-1 +26,-2 Table 2 Outline of the Fictitious Buildings Total floor area Building type Structure Electric energy consumption (KWh/m2 yea Enbodied energy (GJ) Enbodied Carbon emission (ton-c) Water use (m3/m2 year) 2m2 Office S Method BREEAM LEED GBTool CASBEE Table 3 Assessment Results of Case Study Buildings and the fictitious Building nama A B C D fictitious building Building type Office Office Office Office Office PE +DE +MA PE +DE +MA PE +DE +MA PE +DE +MA PE +DE +MA PE +DE +MA Management Health and comfort Energy Transport Water Materials Land use Site ecology Pollution Final Score PE +DE +MA 9 VG EX 9 VG EX 8 VG EX 9 VG EX 4 No rating PASS SS WE EA MR EQ ID TOTAL POINTS PROJECT LEVEL SILVER GOLD SILVER SILVER NOT CERTIFIED R Resource Consumption L Environmental Loading Q Indoor Environmental Quality S Service Quality SCORE Q-1 Indoor Environment Q-2 Quality of Service Q-3 Outdoor Environmental on Site LR-1 Energy LR-2 Resources and Materials LR-3 Off-site Environment BEE Buileing Sustainability Rating A S A A C Notice: In the table, the values show score received on BREEAM, based LEED, GBTool and CASBEE. In the BREEAM, the building performance assessments is show PE, the Design & Procurement Assessments is show +DE and the Management & Operation Assessments is show +MA.

4 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) One low performance building received the assessment result of BREEAM of EPI = 4, No rating in Design & Procurement Assessments, and Pass in Management & Operation Assessment. The assessment result of LEED is Not Certified. The assessment result of GBTool is -.1. The assessment result of CASBEE is C on building sustainability rating based on BEE. These assessment results are low based on each assessment s methods. As mentioned above, the assessment results of each assessment method show a similar trend. But, the assessment results of BREEAM and CASBEE are higher than that of LEED and GBTool. One of reasons for this trend is the difference in criteria. For example, in the criterion of Energy, the best score can be received by reducing the ERR value by 25% of the standard level on CASBEE, or by reducing the energy consumption by 5% of the standard level to receive the best score based on LEED and GBTool. 3. The Comparison of Assessment Results of BREEAM, LEED, GBTool, and CASBEE In this study, to compare the assessment results of each environmental assessment method, the criteria of each assessment method were classified into six categories based on CASBEE s categories. The categories are 1) Indoor Environment, 2) Quality of Service, 3) Outdoor Environment on Site, 4) Energy, 5) Resources and Materials, and 6) Off-site Environment. The assessment results compared the rate of points, credit, or score based on six categories. In the following, the rate of points, credits, or score is referred to as point rate. Fig 3 shows the rate of points, credit, or score in the six categories ) Indoor Environment The point rate shows a similar trend in all of the case study buildings, but building C s point rate on LEED is different from that of the other buildings. The criteria of Noise & Acoustics, Thermal Comfort, Lighting, and Air Quality are applicable to the Indoor Environment category. Based on LEED, Low-Emitting Materials in Indoor Environment are an important criteria. In Building C, credit for Low-Emitting Materials can not be received, so the point rate is lower than that of the others. The criteria of HVAC system and ventilation system are important based on BREEAM. There is no criteria of Noise & Acoustics based on LEED CASBEE BREEAM GBTool 1) Indoor Environment 2) Quality of Service ) Outdoor Environment on Site 4) Energy ) Resource and Materials 6) Off-site Environment Figure 3 The rate of assessment points, credits, or score in the six categories

5 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) 3.2 2) Quality of Service The criteria of Service Ability, Durability & Reliability and Flexibility & Adaptability are applicable to the Quality of Service category. There are no criteria that are applicable to this category based on LEED, and there are few criteria based on BREEAM. However, the Quality of Service is assessed in detail based on GBTool and CASBEE. The point rate shows a similar trend on BREEAM, GBTool, and CASBEE ) Outdoor Environment on Site The point rate follows a different trend based on each assessment method. The criteria of Preservation & Creation of Biotope, Townscape & Landscape and Local Characteristics & Outdoor Amenity are applicable to the Outdoor Environment on Site category. Based on BREEAM, LEED, and GBTool, the criteria of Preservation & Creation of Biotope are more important than the criteria of CASBEE. But the criteria are different in each method. On BREEAM, Creation of a biotope is very important. Based on LEED, site selection is very important. On GBTool, the area of land for building use is very important, along with the criteria of creation of a biotope and site selection. The criteria of Townscape & Landscape and Local Characteristics & Outdoor Amenity are not very important based on BREEAM, LEED and GBTool, but very important based on CASBEE. The four case study buildings were constructed in urban areas and consider the surrounding environment, therefore, the rate on CASBEE is good. Based on BREEAM, LEED, and GBTool, the different measures which consider preservation and creation of biotope affect the point rate ) Energy The criteria of Building Thermal Load, Natural Energy Utilization, Efficiency in Building Service System, and Efficient Operation are applicable to the Energy category. Based on BREEAM, LEED and GBTool, the criteria are assessed for simulation on energy consumption and CO 2 emission, but there are no criteria of Efficient Operation. Based on CASBEE, the criteria of Efficient Operation is important. Based on BREEAM, the criteria of monitoring and commissioning are assessed. On LEED, the criterion of commissioning is a prerequisite item. If the building is not commissioned, the building is not able to be assessed based on LEED ) Resources and Materials The criteria of Water Resources and Materials of Low Environmental Load are applicable to the Resources and Materials category. Water conservation, reuse of existing building structure and volume of recyclable materials are important based on BREEAM, LEED, GBTool, and CASBEE. Based on CASBEE, the criteria of rainwater and a gray water reuse system are a important as the criteria of water consumption. The rate shows a similar trend based on BREEAM, LEED, GBTool, and CASBEE. The point rate of CASBEE is a little higher than that of the others ) Off-site Environment The criteria are those of Air Pollution, Noise, Vibration and Odor, Wind Damage & Sunlight Obstruction, Light Pollution, Heat Island Effect, and Load on Local Infrastructure. The criteria of air pollution are assessed for NOx emission based on BREEAM, GBTool, and CASBEE, but not based on LEED. The criteria of reducing heat island effect is not assessed based on BREEAM and GBTool. The point rate is a little higher based on BREEAM and CASBEE than that based on LEED and GBTool. 4. Conclusion This study is concluded in the following: (1) On BREEAM, LEED, GBTool, and CASBEE, the assessment results of a high performance building are of a similar trend. (2) The assessment results of some high performance building are a little higher based on BREEAM and CASBEE than those based on LEED and GBTool. (3) To compare the features of assessment results on BREEAM, LEED, GBTool, and CASBEE, the criteria are classified into six categories based on CASBEE s criteria. In the Outdoor Environment on Site category, the assessment results are different in each method. The factors are the differences of the criteria in each method. However in on the Indoor Environment category, Quality of Service category, Energy category, Resource and Materials category, and Off-site Environment category, the assessment results show a similar trend.

6 The 25 World Sustainable Building Conference, Tokyo, September 25 (SB5Tokyo) Acknowledgement This study is part of the research output of Japan Sustainable Building Consortium (chaired by Professor Shuzo Murakami of Keio University) and the sub-committee on the study of Green Building Challenge, established within the Institute for Building Environment and Energy Conservation. The authors express sincere thanks to all people associated with this study. <The member of sub-committee on study of Green Building Challenge in 23> Chair : Tatsuo Oka (Utsunomiya University), Vice-chair : Masaaki Sato (KAJIMA Corporation), Hiroaki Takai (TAKENAKA Corporation), Secretary : Nobukazu Kobayashi (Mitsubishi Jisho Sekkei Inc.), Member : Kazuaki Shimada, Yuka Tukada (from Ministry of land, Infrastructure and Transport), Kazuo Iwamura (Musashi Institute of Technology), Yuichiro Kodama (KOBE Design University), Tomoya Yashiro (University of Tokyo), Takao Sawachi, Shiro Nakajima (from Building Research Institute), Noritaka Shinada (Tokyo Metropolian Government), Kunimichi Ishiguro (TAISEI Research Institute), Wataru Urabe (Central Research Institute of Electric Power Industry), Junko Endo (Nikken Sekkei Co,Ltd.), Yoshio Kato (NIHONSEKKEI, Inc.), Nobuhiro Shimada (KANSAI ELECTRIC POWER CO.,Inc), Sadahachi Tanaka (Building and Equipment Life Cycle Association.), Yuji Tubota (TOKYO Electric Power Company), Toshiyuki Miura (TODA Corporation), Hiroshi Yamamoto (TOKYO GAS Co., Ltd.) References Murakami, S. et al. 22, Study on Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) Part 1-9. Summaries of Technical Papers of Annual Meeting Architectural Institute of Japan, pp Murakami, S. et al. 23, Study on Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) Part 1-9. Summaries of Technical Papers of Annual Meeting Architectural Institute of Japan, pp Murakami, S. et al. 24, Study on Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) Part 1-9. Summaries of Technical Papers of Annual Meeting Architectural Institute of Japan, pp CHUN, C. et al. 2, TENDS IN OVERSEAS GREEN BUILDING EVALUATION TOOL. AIJ JOURNAL OF TECHNOLOGY AND DESIGN No.11, pp Yokoo, N. et al. 22, Comparison of assessment results of green housing in Japan by using Eco Homes, LEED, GBTool, and Green housing A-Z. In Proceedings of International conference Sustainable Building 22, Norway, No.147, pp. 1-6