Published papers

Enhancement of the governance and the cooperative structure of local governments toward the reduction of carbon output is becoming more and more important. In this study, the CO2 reduction potential of the town of Yusuhara - selected as one of the “Eco-model Cities for the Low Carbon Society” (EMC) by the Japanese cabinet office - is estimated considering the change of social situation. Such estimation supports local governments to formulate their action plans and contributes to the realization of low carbon society.

Indicators are partial reflections of reality. Those are necessary information we use to understand present conditions in cities, make our decisions, and plan future actions. Since environmental problems such as global warming and biodiversity loss are getting worse, the importance of urban/city assessment indicators as a mirror of current situation is increasing. Urban/City assessment indicators and tools are surveyed in this research, so that it can contribute to the realization of sustainable cities.

Building usage and performance is closely tied to area characteristics. The relation between environmental performance of green buildings and area characteristics is elucidated here by analyzing numerical data on domestic land, using official statistics in Japan together with assessment data from the Comprehensive Assessment System for Built Environment Efficiency (CASBEE) tool and geographic data. Apartment buildings in Yokohama City were analyzed, with hotspot analysis showing a statistically significant hotspot in northwest Yokohama. Furthermore, overlay mapping revealed that the environmental performance of apartment buildings in Yokohama varies with levels of commuting, living alone, and income.

Previous studies have revealed relationships between specific residential environmental factors and residents' health status. However, no previous study has considered the comprehensive health risk due to overall residential environment. Therefore, a large-scale nationwide questionnaire survey was conducted using CASBEE Health Checklist to examine the residential environment of detached houses and residents' health status. Results show that overall residential environment was likely an important determinant of health and was associated with disease prevalence among residents.

A time-series assessment of urban environment was carried out by using “CASBEE-City” tool in Kobe city to visualize the disaster recovery process. As a result of the assessment, it was revealed that the score for quality of Kobe city calculated by the tool got drastically worse soon after the Great Hanshin-Awaji Earthquake in 1995. However, the score for quality of Kobe city has gradually recovered after the earthquake and has improved to the current position along with the progress of the reconstruction.

Environmental performance assessment tool for municipalities (CASBEE-City) has been developed and upgraded since 2008. The tool automatically queries the database and extracts the necessary data for conducting the nationwide municipality assessment. The tool also incorporates GIS functionality and enables tool users to understand the conditions, strengths, and weaknesses of their municipalities in comparison with other municipalities in Japan by visualizing the assessment results on easy-to-understand maps.

It is important to promote energy-saving actions toward the reduction of CO2 emissions in residential sector. Residents should understand the actual conditions of energy consumption in their home in order to make energy-saving actions more effective. Therefore, in this research, a tool which suggests effective energy-saving actions was developed based on literature research and questionnaire survey. A workshop was conducted in Kawasaki City. Then, the residents received the information of their actual energy usage and effective energy-saving actions suggested by the aforementioned tool. As a result, 6.4% of CO2 reduction was achieved.

A comprehensive, nationwide assessment of whole municipalities in Japan was conducted using the Comprehensive Assessment System for Built Environment Efficiency (CASBEE) tool specifically designed for city level assessment (CASBEE-City). As with other tools in the CASBEE family, CASBEE-City is also based on the concept of environmental efficiency and calculates the value for built environment efficiency (BEE). In this study, BEE is calculated by using public statistical information and visually displayed on a map through a geographic information system (GIS) to understand the current situation of all municipalities in Japan under the same assessment criteria (same assessment items, thresholds and rating functions).

CASBEE-City, a comprehensive environmental assessment tool for municipalities (cities, towns, and villages), was developed to support citizens, local governments, and other stakeholders in understanding their local conditions. In this study, the aim was to examine the tool's practical effectiveness through a nationwide questionnaire survey. The statistical relationship was analyzed between the subjective assessment results (citizens' satisfaction with local conditions) and the objective CASBEE-City assessment results, which are based on public statistical information. A clear relationship was found between the subjective and objective assessment results for municipalities, thus verifying the tool's effectiveness.

Population aging is accelerating in many developed countries and there are growing concerns about increasing social security costs. Given this background, as stated in the Japanese Growth Strategy, community that can sustain citizens' lifelong health and active living is required. Therefore, this study aims to develop a healthy community checklist based on citizens' consciousness and behavior survey to recognize the condition of their community and notice the risk factor of disease. Based on the answer of the respondents, the score for a community was calculated and verified the effectiveness of this tool. As the result, the relationship between overall community score and citizens' health condition was quantified. Furthermore, the result showed a significant relationship between the community environment and the personal health, even in the case of considering personal life style.

Competition among cities to become attractive to visitors often leads to loss of place identity and a decline in urban quality for local residents. This study explores the urban identity of Alicante City through a Japan-Spain cross-cultural survey in order to compare visitor and local views. The results, obtained through fieldwork mapping and questionnaires conducted on-site, suggest general qualities of public space, some seemingly related to cultural background (e.g. cleanliness for Japanese, colorfulness for local Spaniards), others to different levels of familiarity with the place (e.g. convenience for locals), and finally qualities like ‘liveliness’ that seem to have a strong cross-cultural appeal. To overcome the loss of urban identity multiple factors need to be addressed. In the case of Alicante the enhancement of street liveliness, as a clear cross-cultural urban quality that seems to satisfy both locals and visitors, can be one of the relevant factors to be considered.

In order to clarify the effect of classroom environmental quality on students' health and learning performance, field measurements, assessments using CASBEE-School (Comprehensive Assessment System for Built Environment Efficiency for school), and questionnaire survey for students and their teachers were conducted in 12 elementary schools. From the results of the survey conducted in both summer and winter, a significant correlation was observed between score for Q1 (indoor environment) category of CASBEE-School and students' satisfaction with their classroom in each school, and effectiveness of assessments by CASBEE-School was validated. However, there is still room for further improvement of assessment system in detail. In addition, a significant correlation between students' satisfaction and both of physical conditions and concentration was observed in this study.

A questionnaire survey was administered to adult residents of three locales: a large city (Kitakyushu city); a small city (Obuse Town); and a rural village (Yusuhara town), in order to clarify the hierarchical structure of health related factors of housing and regional environment dependent on urban structure and scale. As a result of structural equation modeling, health related factors model in Yusuhara was shown that 35% of residents' overall health may depend on their housing and regional environment, and it was the largest percentage of three locales. Besides, differences were found among the health related factors structure. These results indicate that design guidelines for health promotion that correspond to the urban structure and scale will be required.

Toward mitigation of climate change, the Japanese government targeted that greenhouse gas emissions will be reduced by 80% of the 1990 level by 2050. However, CO2 emissions in non-residential sector are rapidly increasing, making carbon reduction in this sector a crucial concern. It is essential to establish CO2 reduction target and agenda based on the analysis of energy consumption and the prediction of the CO2 reduction potential. However, a lack of statistical data of floor area makes it difficult to conduct an analysis and prediction. Therefore, database for floor area of non-residential buildings has been developed in this study. This database includes stock and flow data of floor area by building use type and area which have a major impact on energy consumption in non-residential buildings. This database can provide valuable information for carrying out countermeasures in non-residential sector.

It takes many years to recover the initial investment cost for installing housing insulation through savings from energy reduction (Energy Benefit: EB), since construction cost is very high in Japan. This long payback time is the major barrier to the promotion of well-insulated houses. However, it has been found that if Non-Energy Benefits (NEB) of well insulated houses, such as improvement in personal health, reduction of medical expenses and decline in absences from work are all taken into account, the time required to recover the initial investment cost would change from 29 to 16 years. Therefore recognition of NEB is expected to encourage residents to invest in residential thermal insulation. NEB of well-insulated houses is thus evaluated regarding human health in this study.

Conducting city assessments and disclosing those results to the public is important for supporting citizens' understanding of the actual condition of their city. Such assessment and disclosure could introduce a market mechanism that can be expected to provide city governments with strong incentives to improve their city conditions and also recognizes that local policy and strategy can be the most appropriate way to address specific urban and environmental problems. The latest Comprehensive Assessment System for Built Environment Efficiency (CASBEE) tool, referred to as CASBEE-City, is presented. Designed specifically for city assessment, it supports local governments and other stakeholders in identifying the environmental, social and economic characteristics of their city and in quantifying the effectiveness of their city-wide policies. CASBEE-City is based on the concept of environmental efficiency and it provides a combined evaluation of a city embracing two aspects: the environmental load imposed by the city on the wider environment outside its boundary, and the quality of life (environmental, social, economic) inside the city. A city with low environmental load and high quality receives a high Built Environment Efficiency (BEE) value and is regarded as a sustainable city within the CASBEE framework.

In 2009, the Japanese government published their greenhouse gas (GHG) emission reduction target to reduce GHGs by 25% by 2020 and 80% by 2050. To meet this target, formulating suitable policy has become an urgent issue. In this study, we have developed a model for predicting the low-carbon technology adoption rate based on the detached homeowners’ decision-making structures. In addition, we have considered policies for meeting the reduction target. This study aims to propose policies to meet the reduction target, and to contribute to the realization of a low-carbon society.

It is necessary to consider measures to promote well insulated houses toward the reduction of CO2 emissions in residential sector. However, it is difficult to determine effective measures since residents’ attitude toward introducing insulation differ from one by one. Therefore, in this study, a model for predicting the diffusion process of well insulated house was developed taking residents’ attitude toward introducing insulation into account. The model enables us to consider effective measures for promoting well insulated house. As a result of case study, presenting energy benefits and non-energy benefits was more effective than giving economic incentive in the study.

This paper constitutes the second part of a cross-cultural study on public space in Alicante, Spain. As in other touristic cities, many places in Alicante are polarised between those catering for visitors and those catering for locals. This polarisation often provokes a loss of place identity and a decline in urban quality for locals. This study identifies specific public spaces and the reasons why some are preferred by locals, by Japanese visitors, or by both through cross-cultural group discussions using affinity diagrams as a participatory method. It was found that in many cases when both locals and Japanese preferred the same place, it was for different reasons. This suggests that a way of sharing places by locals and visitors in touristic cities may consist of nurturing enough diversity so as to enable different qualities that can respond to the preferences of different people, including preferences as different as those of the Japanese and Spaniards.