1

Application of CASBEE-City to Various Types of Cities around

the World

Speakers:

Takigami, Masaki1; Ikaga, Toshiharu

2; Murakami, Shuzo

3; Kawakubo, Shun

4

1 Keio University, Yokohama, Japan

2 Keio University, Yokohama, Japan

3 Institute for Building Environment and Energy Conservation, Tokyo, Japan

4 Hosei University, Tokyo, Japan

Abstract: Conducting city assessments can help municipalities determine appropriate measures for

sustainability. However, most city assessment tools are designed for assessing cities in developed

countries, with a particular focus on megacities. This paper describes how an assessment tool for

various types of cities worldwide has been adapted from the “CASBEE for Cities” tool, which was

originally designed for assessing Japanese cities. First, the tool is validated by assessing whole

municipalities in Japan. Generally, in Japan, living standards are higher than the world average and

the environmental load is also correspondingly higher. These findings are verified quantitatively by

using the tool. To extend the tool’s utility beyond Japan, a rapidly developing municipality in

Malaysia is assessed to verify the tool’s practicality in other types of cities. Assessment data were

gathered through interview surveys and used as input to the tool. The results quantitatively show that

conditions in the city should be improved.

Keywords, CASBEE, Foreign City Assessment, Triple Bottom Line, Environmental Efficiency,

Public Statistical Information

1. Introduction

As of 2008, more than half of the world’s population is living in urban areas; this figure is

expected to rise to 70% by 2050. In today’s era of cities, more and more cities around the

world are making efforts to become more sustainable. Adoption of the Charter of European

Sustainable Cities and Towns Towards Sustainability, also known as the Aalborg Charter, has

increased awareness of the importance of actions at the city level to create a sustainable

society.1 In recent years, many academic investigations of city assessments for sustainability

have been conducted. For example, the GaWC study,2 Global Cities Index,

3 Global Power

City Index,4 and Global City Competitiveness Index

5 are several well-known city assessment

indices. However, most city assessment tools and indices are developed for assessing only

domestic cities or are specifically designed for assessing cities in developed countries due to

the availability of and access to data for these types of cities. In this study, an assessment tool

for cities around the world is developed. Cities of every type and size can be assessed by the

tool if the data necessary for assessment are gathered.

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2. Methodology

2.1 Development of an Assessment Tool for Cities around the World

This section describes modifications to the Comprehensive Assessment System for Built

Environment Efficiency (CASBEE) for Cities tool (hereinafter, CASBEE-City) to allow for

assessment of cities around the world. Originally, the tool was designed for assessing

municipalities in Japan.6,7,8

CASBEE-City assesses whole municipalities in Japan and enables

understanding of the actual conditions in each municipality in terms of environmental, social,

and economic aspects.

2.2 Assessment for Quality

CASBEE-City calculates each city’s score by using a large database in which information on

various cities is stored. The database

information is modified for use in

the tool. Figure 1 and Equation 1

show the assessment methodology

and the scoring function for quality.

The score for quality is calculated

according to a continuous function

so that the effect of measures

implemented by municipalities

accurately reflects the amount of

effort. The scoring function should

be different for each assessment

item in the subcategory to make the effects of city actions become apparent. As a

consequence, a cumulative relative frequency (i.e., percentile rank) curve has been adopted as

the scoring function for each subcategory and these subcategory results are converted into the

overall score. Histograms and graphs are created for each quality subcategory. The score for

quality is calculated on this curve by applying weight coefficients to scores in various major,

minor, and subcategories. The target city is assessed “relatively,” with the percentile score

depending on the group being assessed. The assessment group in CASBEE-City is set to

“whole municipalities in Japan.” In this study, this assessment group has been expanded to

assess whole cities around the world. In other words, each scoring function has been

customized. To expand the range of each assessment item, public statistical data has been

collected from around the world. For practical reasons, rather than using data for only cities,

national data are collected. In the original version, city-level data are desirable for creating the

scoring function. However, to expand the tool, national-level data are used as averages for all

cities in each country, and each scoring function is created as follows.

−∑ ×

×∑

∑ ××= 1)(25

ii

wij

w

kijk

wijk

QQualitytalEnvironmenforScore ｊ (1)

Figure 1. Scoring method for quality

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Each subcategory (Qijk) is assessed on a five-point scale corresponding to the conditions in a

city (higher scores indicate higher sustainability). In Equation 1, w (0 ≤ w ≤ 1) values are

category weights, with subscripts corresponding to major (i), minor, (j), and subcategories (k).

Table 1 shows the assessment items for CASBEE-City before and after the modifications for

worldwide use. Assessment items in the modified tool should be broadly the same as in

CASBEE-City. However, some assessment items have been converted to similar or more

suitable items to apply the tool to a broader range of cities rather than just Japanese cities.

National statistical data are collected from various organizations, such as the United Nations,

World Bank, and World Health Organization, whose statistical data can be considered as

Table 1. Assessment items for quality and load (Upper: original items; lower: modified items)

Category Assessment item

Major Minor Subcategory (original items)

Qu

alit

y Q

Q1

. E

nv

iron

men

tal

asp

ect Q1.1

Nature conservation

Q1.1.1

Ratio of green and water spaces

(Forest area + Major lake area) / Total land area

No change

Q1.2

Local environment

Q1.2.1

Air

The number of days which hourly photochemical oxidant concentrations during the day are 0.12

The average annual exposure level of the average urban resident to outdoor PM10

Q1.2.2

Water

75% of daily average biochemical oxygen demand in a river

Proportion of the population using improved drinking water sources

Q1.3

Resources recycling

Q1.3.1

Recycling rate of general waste

Recycling rate of general waste

Municipal waste collected / Total population

Q1.4

CO2 sinks

Q1.4.1

CO2 absorption by forests

Current forest area * unit of absorption (2.92 t-CO2/ha) / Adjusted population

No change

Q2

. S

oci

al a

spec

ts

Q2.1 Living environmental

Q2.1.1 Adequate quality of housing

Total floor area per dwelling unit

Q2.1.2 Traffic safety

Number of traffic accidents / Adjusted population

Number of road traffic deaths / Total population

Q2.1.3

Crime prevention

Number of crimes recorded / Adjusted population

Number of intentional homicide / Total population

Q2.1.4

Disaster preparedness

Number of disaster response hospitals per 100,000 persons in adjusted population

Number of hospital beds / Total population

Q2.2

Social service

Q2.2.1

Adequacy of education service

Number of students at elementary and junior high schools / Number of teachers at elementary and junior high schools

No change

Q2.2.2

Adequacy of cultural services

Number of community centres + Number of libraries / Land area of municipality

Number of Internet users / Total population

Q2.2.3

Adequacy of medical services

Number of physicians / Adjusted population

No change

Q2.2.4

Adequacy of childcare services

Number of childcare facilities / Infant population (aged 0 to 4)

Number of pre-primary students / Infant population (aged 0 to 4)

Q2.2.5

Adequacy of services for the elderly

Number of senior care facilities / Senior population ( aged 65 and over)

Number of nurses and midwives / Total population

Q2.3

Social vitality

Q2.3.1

Rate of population change due to births & deaths

Rate of increase / decrease in the natural population = Increase / decrease in the natural population in one year

Rate of population change due to births, deaths and migration

Q2.3.2

Rate of population change due to migration

Rate of population change due to migration = Number of new residents

(Male life expectancy + Female life expectancy / 2

Q3

. E

cono

mic

asp

ects

Q3.1

Industrial vitality

Q3.1.1

Amount equivalent to gross regional product

(Agricultural output + Value of manufactured goods shipments + Annual sales of commercial goods) / Adjusted population

GDP (Gross Domestic Product) / Total population

Q3.2

Financial viability

Q3.2.1

Tax revenues

Tax revenues the local government / Adjusted population

Number of employed persons / Total population

Q3.2.2

Outstanding local bonds

Real debt service ratio

Number of unemployed persons / Labor force size

Q3.3

Emissions trading

Q3.3.1

Amount of emissions trading

Existence or nonexistence of emissions trading

No change

Lo

ad

CO2 emissions per person

Total CO2 emissions from each sector / Adjusted population

Total CO2 emissions from each sector / Total population

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objective and reliable.

2.3 Assessment for Environmental Load

Equation 2 shows the assessment methodology for environmental load emitted from the target

city. CASBEE-City converts the total amount of CO2 emissions per capita into a score from 0

(good) to 100 (poor).

)exp(11100

aXLoadtalEnvironmenforScore

−+×= , where X=log10 x-log10µ (2)

As in CASBEE-City, CO2

emissions are converted to a score

by using a logistic equation.

However, because the range of

CO2 emissions can range from

virtually nothing to an extremely

large value globally, the

assessment range is expanded in

the modified tool. Thus, the

explanatory variable for CO2

emissions is converted to a

logarithmic scale. Here, a is the

gain, which controls the curvature of the logistic curve, x represents the amount of emissions

from the target city, and µ represents the present world average emissions amount. Figure 2

shows the curve created by the logistic equation. Two reference points have been set. First,

CO2 emissions equal to the present world average rate is assigned a value of 50 points. When

the value of x is 0.94 t-CO2/person/year, 12.5 points is assigned as a second reference point,9

which is the point where the target city achieves an 80% reduction over the current world

average, in accordance with the long-term target for developed countries.

3. Results and Discussion

3.1 Reassessment of Whole Municipalities in Japan

Whole municipalities in Japan were reassessed using the modified tool for verification against

the prior model. All assessment items must be checked for validity because some assessment

items have been changed in the modified tool.

Figure 3 compares the results for the quality of whole municipalities in Japan as assessed by

the original and modified tool, using the assessment items in Table 1. The left figure shows

the quality scores using the original and modified assessment items. Only small differences in

quality scores were observed after assessment items were changed (the slope of the regression

line is about 1). The assessment items are also quantitatively verified to some extent because

variation of the score differences between the original and modified items are small (the

standard deviation of the score differences is about 6.47). The right figure shows the quality

Figure 2. Scoring method for environmental load

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scores using the original and modified assessment range. “After modified” corresponds to the

world assessment range and “Before modified” corresponds to the Japanese assessment range

(i.e., from CASBEE-City). All plots are located above the diagonal, in other words, score for

whole municipalities were improved after assessment range was expanded. This means that

the living standard in municipalities in Japan exceeds the world average (= 50 points).

Figure 4 shows the assessment results for whole municipalities in Japan using the modified

tool. The results are shown on a two-dimensional built environment efficiency (BEE) chart in

which the vertical axis and horizontal axis show city quality from 0 (worst) to 100 (best) and

environmental load imposed by the city from 0 (best) to 100 (worst), respectively. The main

contribution of this study is expanding the Japanese assessment scale of the original

CASBEE-City tool to be a global assessment scale. For example, a score of 50 points is

updated in the world city tool to indicate the world median score instead of the median score

in Japan. Almost all municipalities in Japan exceeded 50 points for both quality and load.

This means that the living standard in Japanese municipalities exceeds the world average. On

the other hand, most Japanese municipalities impose an environmental load greater than the

world mean (where 50 points corresponds to 4.56 t-CO2 annually per capita), so reductions in

CO2 emissions are required.

3.2 Assessment by Field Survey of a Rapidly Developing Municipality in Malaysia

After the modified tool was developed, Putrajaya

city (located south of Kuala Lumpur), a rapidly

developing municipality in Malaysia, was assessed

to test the practicality of the tool. Figure 5 shows

an aerial view and photos of the city. A field

survey to collect necessary statistical data for

assessment was conducted through interview

Figure 4. Comprehensive assessment results for whole municipalities using the original (left) and modifed

(right) tool

Figure 7. Assessment result for minor assessmnet categories

Figure 5. Map and Photos of Putrajaya

Figure 6 Assessment results of Putrajaya

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surveys and input into the tool. However, some data which were not available for the

municipality were replaced with Malaysian average values. Figure 6 shows the assessment

results for Putrajaya city. The BEE for Putrajaya is currently slightly lower than the world

average of 1.0. This result indicates that, from a sustainability perspective, load reduction is

more urgent than improvements in quality. Figure 7 shows results on the minor assessment

categories shown in Table 1. Almost all scores are higher than the world average of 3.00

points. From Figure 5, it can be seen that lakes and green space are adequate and, as a result,

the score for Q1.1 is high. However municipal waste (Q1.3) is being collected by the

municipality or a company at less than the world average level. This indicates that

implementing waste-related measures should have a higher priority than other environmental

measures. It is also necessary to increase amount of CO2 absorption (Q1.4). In the report

“Putrajaya Green City 2025,” a total of one million trees are planned to be planted in

Putrajaya by 2025.10

Although this effort has not been quantitatively assessed yet, the score

will be drastically improved when the plan is carried out. Social aspects (Q2) of Putrajaya

score much higher than the world average. The main cause of the high score for Q2.1 is the

high security level of the city. No murders occurred in Putrajaya during the target year. Social

services (Q2.2) also scored higher than the world average. The construction of Putrajaya was

started in 1995, and almost all governmental functions have been transferred to the city. Many

kinds of social functions are sufficient. This transfer of governmental functions also will

result in a high score for Q2.3 because the population will be concentrated in the capital. The

employment rate is high and unemployment is low in Putrajaya. Although the score is high,

many personnel are working in government agencies, rather than private businesses. It should

be noted that this employment system is rather unique compared with many other cities, but

these assessment results are tentative. To finalize the results, continued cooperation with the

local government at Putrajaya is required.

Acknowledgements

We thank the administrative officers in Putrajaya City, whose support and insightful

comments were invaluable during the course of this study. We also give special thanks to the

Committee for the Development of an Environmental Performance Assessment Tools for

Cities (Chair Shuzo Murakami) for providing advice that was essential to the successful

conclusion of this study.

References

(1) Aalborg Charter (1994), European Conference on Sustainable Cities & Towns, ‘Charter of

European Cities and Towns Towards Sustainability’, Aalborg, Denmark, 27 May, 1994.

(2) Globalization and World Cities Research Network (2014), The World According to

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on 21 May 2014).

(3) A.T. Kearney (2014) ,2014 Global Cities Index and Emerging Cities Outlook, [online]

(available at:

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http://www.atkearney.com/documents/10192/4461492/Global+Cities+Present+and+Future-

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(7) Kawakubo, Shun; Murakami, Shuzo and Ikaga, Toshiharu (2011), Nationwide Assessment

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(8) Kawakubo, Shun; Ikaga Toshiharu, Murakami Shuzo and Asami Yasushi (2013),

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(10) Universiti Teknologi Malaysia (2012), Putrajaya Green City 2025, [online]

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