The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005

The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

04-014

COMPARISON OF THE ASSESSMENT RESULTS OF BREEAM, LEED, GBTOOL AND CASBEE Yukihiro KAWAZU1 Nobuhiro SHIMADA 2 Noriyoshi YOKOO Dr. Eng1 Tatsuo OKA Dr. Eng1 1

2

Department of Architecture, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan, [email protected] [email protected] [email protected] Kansai Electric Power, 3-6-16 Nakanoshima, Kita-ku, Osaka 530-8270, Japan, [email protected]

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 1990’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 1990’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 1990, 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 2003. 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’.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

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. 2.1.1 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. 2.1.2 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. 2.1.3 GBTool The score is high in all categories, especially on L (Environmental Loading) and S (Service Quality). The factors are as follows; reducing CO2 emission by energy saving, using no halon fire retardant and refrigerant of ODP=0 for reduced atmospheric emission leading to ozone depletion, ample freedom for planning equipment and space, and using a vibration dampening system.

Pollution

Site ecology

Materials

Land use

Transport

Water

Management & Operation Assessments

Lost Points

1) BREEAM No

Innovation & Design Process

Indoor Environment Quality

Materials & Resource

use of refrigerant of ODP=0

Energy & Atomosphere

Water Efficiency

Yes

2) LEED

5.0 4.0 3.0

building thermal mass system

2.0 1.0

S Service Quality

Q Indoor Environmental Quality

-2.0

L Environmental Loadings

0.0 -1.0

R Resource Consumption

use of underground water for

use of no haron fire retardant

Design & Procurement Assessments

18 16 14 12 10 8 6 4 2 0

Total

heat reflective pair glass

use of a large difference air conditioning

Building Performance

Sustainable Sites

control of the lighting by natural lighting

continuous air-conditioning for 24h

Energy

radio tower

solar panel

Health and comfort

natural ventilation by the radio tower

Management

parabolic antenna

250 200 150 100 50 0

3) GBTool Building type Location Site area Total floor area Floors Structure

Office Kobe city, Hyogo prefecture 3349 33295 +19,-2 Above the ground S Below the ground RC,SRC

Q-1 Indoor Environment

Q-2 Quality Service 5 4 3 2 1 0

LR-3 Off-site Environment

Q-3 Outdoor Environment on Site LR-1 Energy

LR-2 Resources and Materials

Figure 1 Outline of A building

4) CASBEE Figure 2 The assessment results of Building A

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

2.1.4 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 50% 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 2.2.1 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 1. 2.2.2 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 2. 2.2.3 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 Table 2 Outline of the Fictitious Buildings Location Structure

Total floor area Completion Floors

A Hyogo Above the ground :S under the ground :RC SRC 33,000 2000 +19,-2

B Tokyo S,SRC

C Tokyo CFT

D Kanagawa S,SRC

106,000 2002 +37,-4

9,000 2002 +10,-1

80,000 2000 +26,-2

Total floor area Building type Structure Electric energy consumption （KWh/㎡･yea Enbodied energy (GJ) Enbodied Carbon emission (ton-C) Water use (㎥/㎡･year)

2000㎡ Office S 200 24344 6352 2.4

Table 3 Assessment Results of Case Study Buildings and the fictitious Building nama

Method

A Office

Building type PE

+DE

+MA

Management Health and comfort Energy Transport Water Materials Land use Site ecology Pollution Final Score

BREEAM

PE

+DE

+MA

SS WE EA MR LEED EQ ID TOTAL POINTS PROJECT LEVEL R Resource Consumption L Environmental Loading GBTool 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 CASBEE LR-2 Resources and Materials LR-3 Off-site Environment BEE Buileing Sustainability Rating

PE

0 54 96 80 12 16 0 0 84 324 9

+DE

0 6 0 0 0 0 16 48 14 426 VG

8 2 7 3 13 0 33 SILVER 2.0 2.6 2.3 2.7 2.3 3.6 4.1 4.1 4.5 2.9 3.7 2.5 A

C Office

B Office +MA

90 42 40 16 12 0 0 0 14 556 EX

PE

0 60 104 64 18 16 0 0 56 310 9

+DE

30 18 0 0 0 16 16 48 0 438 VG

8 3 8 5 13 3 40 GOLD 2.2 2.8 2.0 3.2 2.4 4.1 4.1 4.7 4.1 3.8 4.1 3.2 S

+MA

120 36 40 16 12 16 0 0 14 564 EX

PE

0 54 96 64 18 16 0 0 42 290 8

+DE

30 18 0 0 0 0 16 48 0 402 VG

6 2 6 5 12 3 34 SILVER 2.0 2.3 2.2 2.6 2.2 4.0 3.9 2.7 4.6 3.3 3.5 2.8 A

fictitious building

D Office +MA

90 36 40 16 6 8 0 0 14 500 EX

PE

0 60 64 80 18 16 0 0 84 322 9

+DE

30 6 0 0 0 24 32 64 0 478 VG

7 4 8 4 10 3 36 SILVER 1.7 2.7 3.3 3.7 2.9 3.9 4.3 5.0 4.1 2.6 4.7 2.6 A

Office +MA

120 36 32 16 12 16 0 0 14 568 EX

PE

0 12 24 64 0 0 0 0 56 156 4

+DE

0 0 0 0 0 0 0 16 0 172 No rating

+MA

0 6 0 8 0 0 0 0 0 170 PASS

2 0 0 2 5 0 9 NOT CERTIFIED -0.2 -0.3 0.3 0.1 -0.1 2.2 2.4 1.7 2.7 2.0 1.5 0.4 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.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

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 -0.1. 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 50% 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. 3.1 1) 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. 100 80 60 40 20 0

100 80 60 40 20 0 CASBEE

LEED B

BREEAM C

D

GBTool

CASBEE

A

BREEAM B

1) Indoor Environment

C

GBTool D

A

2) Quality of Service

100 80 60 40 20 0

100 80 60 40 20 0 CASBEE

LEED B

BREEAM C

D

GBTool

CASBEE

A

LEED B

3) Outdoor Environment on Site

100 80 60 40 20 0

BREEAM C

D

GBTool

A

4) Energy

100 80 60 40 20 0 CASBEE

LEED B

BREEAM C

D

GBTool

CASBEE

A

LEED B

5) Resource and Materials

BREEAM C

D

A

6) Off-site Environment

Figure 3 The rate of assessment points, credits, or score in the six categories

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GBTool

The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

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. 3.3 3) 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. 3.4 4) 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 CO2 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. 3.5 5) 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. 3.6 6) 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.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

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. 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.)

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