Published papers

The nexus structures of the UN sustainable development goals were analyzed by data-driven approach, such as sparse modeling and network analysis technologies. As the results, Japanese society formed a nexus structure between SDGs global goals and targets, and the nexus structures inferred from Local SDGs indicator database and extracted from SDGs future city plans had different characteristics. Our work can be utilized to help the comprehensive understanding of synergies and trade-offs among SDGs and support the inclusive planning, policy design and partnership beyond all sectors.

The United Nations’ (UN) sustainable development goals (SDGs), the core of the 2030 Agenda for Sustainable Development and the UN Paris Agreement, were adopted in 2015. Involvement of not only national governments but also all other stakeholders including local governments is important to promote sustainable development and to achieve the goals. The question arises, therefore, of what methods should be used to best implement and assess sustainability issues at a local level. In this light, a new version of Comprehensive Assessment System for Built Environment Efficiency (CASBEE), CASBEE for Cities, is introduced for assessing the sustainability of cities and communities around the world based on SDG indicators and greenhouse gas (GHG) emissions. The tool allows users to understand the sustainability of cities and communities based on quality (Q) and environmental load (L) perspectives. The sustainability assessments show that cities in developed countries tend to have good grades for Q, but bad grades for L, while cities in developing countries tend to have the opposite trend. This will assist cities and communities in both developed and developing countries to understand urgent problems and to identify effective solutions for sustainable development.

Mixed-mode ventilation has been attracting attention as an air conditioning method for improving IEQ and for energy saving in buildings. This study measured the indoor environment and power consumption of air conditioning in an office building with mixed-mode ventilation in spring. The results showed that PMV remained at 0.0 - 0.5 with mixed-mode ventilation, and that the power consumption of air conditioning was approx. 72.8 %-82.1 % lower than that of floors without mixed-mode ventilation, and the ventilation volume exceeded the benchmark of 30 m3/h per person.

Conducting assessments using city resilience indicators based on public statistical information helps us to understand the actual conditions and resilience of our cities and communities, thereby enhancing our ability to resist, adapt to, and recover from devastating disasters. The paper introduces the methodology and procedure of developing city resilience indicators and a case of conducting resilience assessment using the indicators targeting major cities in Japan. Initially, 18 indicators were carefully selected based on selection criteria; 1) data availability, 2) data reliability, 3) representativeness, 4) local adaptability, and 5) policy relevance. Secondly, resilience of major Japanese cities including Tokyo and government-designated cities were assessed using these 18 city resilience indicators and 3 integrated indicators. These results were illustrated on a radar charts and scatter charts. Results of the study show the importance of conducting resilience assessment using several indicators together with public statistical information.

Company health management is known to have a positive impact on employee work performance and health. Good office environments are also known to improve employee performance and health. However, do certified health management companies consider the maintenance of a superior office environment as a means to maintain high levels of employee performance and health? This study examined whether certified health management companies have better office environments and if their certification in health management is positively related to employee outcomes. A cross-sectional questionnaire survey of 1644 employees across 61 companies in Tokyo, Japan, collected data on their perception of office environment quality and perceived outcomes. A company was deemed to be engaged in health management if it had received certification for health management. The results of the comparison, after controlling for covariates with propensity score matching, showed that certified health management companies tend to have employees who are more satisfied with their office environment and have a higher perceived office environment. In addition, employees in these companies were found to have better perceived outcomes. These findings underscore the importance of integrating healthy office environments into company health-management strategies.

Despite the fact that housing represents a fundamental unit of urban systems where people spend much of their daily lives, little attention has been paid to the structural relationship between residential environments and subjective well-being. In this study, structural equation modeling was used to analyze the structural relationship between residential environment and subjective well-being, controlling for the effects of demographic factors and personality traits. An online survey of 1,001 adult residents in Japan measured subjective well-being and assessed residential environments, consisting of the thermal, acoustic, light, hygiene, safety, and security. The model revealed an important pathway from the residential environment to subjective well-being mediated by life-domain satisfaction. The six environmental components described above all contributed substantially to the latent residential environment construct, with safety and hygiene showing the highest loadings. This study contributes to a more fundamental understanding of the structural relationship between residential environments and subjective well-being. It also provides insights into designing better residential environments that enable everyone to live in healthier and more supportive spaces—an endeavor that is crucial for promoting sustainable and inclusive urban development, particularly in terms of enhancing overall quality of life.

The efforts of local governments are essential to achieving the Sustainable Development Goals (SDGs). To support these initiatives, an online platform providing SDG-related information was developed. The platform offers two main functions: searching for and sharing information. Users can search for plans, progress, and exemplary cases related to the SDGs across 1,788 local governments, while local governments can voluntarily share their own exemplary cases. Since its launch in 2018, the platform has been utilized by approximately 400 local governments, facilitating widespread information sharing.

In Japan, the energy consumption of the residential sector is significantly high. Therefore, insulation retrofitting and behavioral changes have become critical to enhance energy efficiency. Although several studies have examined these factors, they have focused on standard dwelling units and generalized lifestyle patterns. This study investigated, through simulations, the impacts of thermal insulation performance and lifestyle behavior on energy consumption, health, and economic efficiency of an actual Zero Energy House (ZEH)-certified dwelling installed with a dual-generation system combining photovoltaic panels and a solid oxide fuel cell. The simulation model was validated using energy consumption and indoor temperature data from the winter of 2024; resident interviews were also incorporated to reflect their behavior. Results showed that the primary energy consumption exceeded the ZEH design values, mainly owing to higher-than-expected lighting and gas consumption. Lighting was used in unoccupied rooms, and water heating was frequently used. Operating floor heating systems for only approximately 3 h per day was sufficient to maintain indoor temperatures above 18 °C, the WHO-recommended minimum in winter. Regarding the building envelope performance, residents’ morning blood pressure was estimated at 127.5 mmHg; however, a lower thermal insulation performance resulted in an increase in blood pressure to 137.6 mmHg, exceeding the 135 mmHg threshold, indicating potential health risks. Behavioral optimizations, such as controlling the use of unnecessary lighting, high-efficiency appliances, and water heating systems, reduce energy consumption by 15% and improved economic efficiency by 33%, without compromising health. Moreover, even when operating 24-hr floor heating, these behavioral optimizations contribute toward reducing energy consumption by 11% and improving economic efficiency by 25%.

This paper introduces a comprehensive assessment tool of the built environment of cities, referred to as “CASBEE-City”. The tool supports local governments and other stakeholders in identifying environmental, social and economic characteristics of their cities and to quantify the effectiveness of city-led policies. As for the other CASBEE tools, CASBEE-City also implements the concept of environmental efficiency and allows evaluation of a city from two aspects simultaneously: the aspect of decreasing negative environmental load emitted outside the city, and that of improving environmental quality and activities inside the city. It is expected to contribute to the realization of sustainable cities.

In this study, we examined the usefulness of text mining for newspaper articles as a method of overviewing trends in topics related to the SDGs. Specifically, we collected newspaper articles containing SDGs from the Asahi Shimbun, and attempted to understand the chronological trends in the number and volume of articles in question, as well as to visualize the relationships between words that appear. As a result, we were able to demonstrate the usefulness of text mining for newspaper articles.

In regards to the SDGs future cities throughout Japan, we conducted content analysis of 154 future city plans and interview surveys with 15 local government officials. Our investigation traced shifts in local SDGs policies' priorities, methods of SDGs response in comprehensive plan, the current state of internal and external dissemination in local offices, and the challenges faced in promoting SDGs. We found that SDGs mapping in future cities serves not only as a training tool in the SDGs department but also for other administrative departments. Compared to previous studies, the challenges future cities face differ from those in other local governments. For instance, some future cities have faced unique issues stemming from progressive initiatives.

To achieve Safe and Just Operating Space (SJOS), considering Planetary and Social boundaries, Evaluating SJOS performance at local levels is essential. This study attempted to build an indicator database in the prefecture scale and evaluate SJOS performance and analyzed the overshoots and shortfalls based on the global threshold. The result showed that although carbon emissions and ecological footprint overshoot, most prefectures have sufficient social infrastructures. The next challenge is to fill the data gaps in the Planetary boundaries indicators and explore the localized indicators for SJOS evaluation.

Municipalities have played a crucial role in achieving the Sustainable Development Goals (SDGs) in recent years. This study analyzes changes in awareness, interest, and implementation related to SDGs among municipalities in Japan, based on annual surveys conducted from 2018 to 2024. The results show that SDG awareness and interest increased significantly until 2020 and then stabilized. Implementation efforts continued to improve but varied by municipality size. Changes in barriers to SDG promotion were also examined, providing policy insights.