Enhancing Disaster Resilience for Sustainable Urban Development: Public–Private Partnerships in Japan

Abstract

A resilient building environment is crucial for securing sustainable development in urban areas, as the 2030 Agenda for Sustainable Development Goal 11 stresses. In developing countries in particular, the risk of disasters is increasing due to the poorly built environment caused by urbanization. However, building disaster resilience in vulnerable urban environments characterized by aging houses, limited public spaces, and complex land rights and tenancy issues poses a major challenge. This study aims to identify critical factors influencing effective disaster-resilient urban development by examining Japan’s experience, with a focus on approaches facilitating public–private partnerships. Driven by disasters like the 1995 Kobe Earthquake, Japan has promoted innovative strategies to improve urban resilience and mitigate disaster impacts. The Disaster Mitigation Zone Implementation Program represents a novel program designed to revitalize densely populated areas with aging wooden structures highly vulnerable to disasters. Through semi-structured interviews, a literature review, and an in-depth case study in Tokyo, this research analyzes the development and effectiveness of this targeted redevelopment approach. Findings underscore the pivotal role of policies promoting public–private collaboration, consensus-building mechanisms among stakeholders, flexibility in project formulation, and financial incentives via government subsidies. Engaging the private sector ensures project feasibility through urban development expertise, while simpler, smaller-scale projects attract greater private investment. Japan’s experience offers valuable insights into collaborative, context-sensitive strategies for enhancing urban disaster resilience through targeted redevelopment of high-risk areas.

1. Introduction

Making vulnerable cities resilient to disasters is a challenge [1,2]. Densely built-up areas with poorly constructed buildings are vulnerable to disasters such as earthquakes and fires. In developing countries in particular, the risk of disasters is increasing due to the poorly built environment caused by urbanization [3]. Once a disaster occurs, damage to human life, property, public services, and the environment can hinder sustainable development in urban areas. A resilient built environment is critical to ensuring sustainable development in urban areas, as emphasized in the 2030 Agenda for Sustainable Development Goal 11. To improve the poorly built environment, buildings must be demolished, relocated, and rebuilt, which requires a complex process of financing, consensus building, and coordination. Some countries, such as Chile, Indonesia, India, and Turkey, have introduced urban development approaches to resolve these issues [4,5,6,7].

This study aims to identify factors affecting disaster-resilient approaches to urban development by examining Japanese experience. Further, it proposes approaches to creating resilient cities through public–private partnerships. The Japanese experience offers valuable lessons on effective disaster-resilient urban development strategies for developing countries facing the risk of disasters from urbanizing in poorly built areas.

Japanese cities have historically suffered from earthquakes and fires due to the high population density caused by geographical conditions and the large number of wooden houses for historical and cultural reasons. Such densely built-up areas with wooden structures are subject to significant damage from collapsed houses, simultaneous fires, and large-scale fire spread when an earthquake occurs. In addition, houses collapse or fall into narrow streets, hampering rescue efforts, firefighting, and evacuation. The areas consist of aging wooden houses on small lots of land and limited public spaces of narrow streets and parks, inhabited by elderly people, and have complicated land rights and leasehold rights.

Japan has developed and implemented the Disaster Mitigation Zone Improvement Program (DMZIP), which transforms densely built-up areas with aging wooden houses into disaster-resilient buildings with public space [8,9,10]. The country has evolved this program based on experiences from the Great Hanshin-Awaji (Kobe) Earthquake in 1995 and the Great East Japan Earthquake and Tsunami (GEJE) in 2011.

Semi-structured interviews were conducted with local government officers, experts, and private sector staff who are involved in the programs to improve densely built-up areas with wooden houses. Government documents and research papers were reviewed to examine the evolving process of policies and programs. The study conducted a comparative analysis of DMZIP cases implemented in Tokyo.

2. Urban Development Schemes to Improve Resilience

Urban development schemes converting land and building rights are useful tools for making cities resilient to disasters [11]. This section reviews recent studies examining cases in Japan and other countries. These studies have covered limited cases of application for public–private partnerships and issues of consensus building, which this study focuses on.

2.1. Japan’s Case of Urban Development for Disaster Recovery

Japan developed policies for disaster recovery to make towns resilient against fires and earthquakes based on experiences at the Great Kanto Earthquake in 1923, post-war rehabilitation from World War II, the Kobe Earthquake in 1995, and other disasters [12]. The country has promoted a land pooling, or readjustment, program as a major approach tool. This program enables urban areas to be resilient to disasters by securing public spaces for disaster management on wider roads, parks, and disaster-resilient buildings [7]. The land-pooling projects, covering some 3500 hectares in Tokyo and Yokohama, were completed by 1930 [13]. To recover from World War II, land-pooling projects of 28,000 hectares were completed in 102 cities [14]. Following the Kobe Earthquake, 20 land-pooling projects with 256 ha were implemented [15].

In the land pooling program, landowners donate a small amount of land as reserved land in accordance with their rights, and the reserved land is used to build new roads, parks, and other public facilities, or a portion of the reserved land is sold to finance the project. Project funds consist of revenues from reserved land and construction budgets for roads and public facilities to be borne by government organizations. These funds are used for the construction of public facilities, the development of residential areas, and compensation for residential relocation. Although the land area for each landowner after the land pooling project becomes smaller than before, the construction of public facilities such as roads and parks and the land readjustment enable landowners to obtain residential land with high utility value.

In addition, government organizations have used the urban redevelopment program. In this program, the new floor area created by the advanced use of the land is sold to new residents and business owners to pay for the project. The former building and landowners could receive apartment units in the newly constructed buildings (the “right-of-use floor space”), which is equal to the valuation of their former assets.

2.2. Disaster Mitigation Zone Improvement Program

Japan created DMZIP to improve the disaster resistance of built-up areas with old wooden houses, even under low-profit conditions. The conventional programs of land pooling and urban redevelopment are formulated under the conditions of improving land convenience and increasing land prices during the period of economic growth. Therefore, these programs are not necessarily applicable to areas with a high concentration of wooden houses.

Yamagiwa and Okai [10] emphasized that DMZIP has the advantage of flexibility in defining project zones, which leads to easier consensus-building. On the other hand, the program is not land-intensive, which makes it difficult to be profitable. Without government subsidies or in combination with other projects, project feasibility becomes low. Koido [8] examined two cases in Tokyo from a practical perspective. He noted that the program has the advantage of flexibility, leading to quick implementation compared to other urban development programs. Tabe et al. [9] pointed out that deregulation of housing construction does not motivate houseowners to reconstruct their houses in densely built-up areas.

2.3. Cases in Developing Countries

Urban development schemes are effective even for developing countries with limited financial capacity. In Banda Aceh, Indonesia, a land pooling, or readjustment, program succeeded in rehabilitating a residential area of 248 houses. The success was attributed to foreign assistance and strong leadership at the village level [4]. Following the 2001 Gujarat Earthquake in India, Bhuj City implemented land pooling schemes to rehabilitate devastated urban areas. Byahut and Mittal [16] assessed that the city government was able to achieve a rapid recovery to a safer city, efficient restoration of facilities with minimal land acquisition, limited displacement of residents and businesses, and preservation of community ties. Mathur [17] identified lessons learned from land pooling and reconstruction schemes implemented in Gujarat, including the following: (1) establishing a revolving fund to use revenues from previous projects to finance infrastructure and services for new projects; (2) creating a mechanism to resolve land tenure disputes; (3) establishing an extensive grievance redressal process; and (4) building infrastructure early to gain landowners’ support.

There are some issues with land-pooling projects. Karki [18] found various issues for land pooling projects in Nepal, including inconsistence with urban policies, difficulties of consensus building among landowners, inaccuracy of land records, and limited capacity of implementers.

3. Issues of Densely Built-Up Areas in Japan

3.1. Risks of Densely Built-Up Areas

Vulnerable old houses are concentrated specifically in the densely built-up wooden areas of the inner city in Japan. Densely built-up areas are widely distributed around the urban centers of large cities such as Tokyo and Osaka. They were formed from historical city allotments during the beginning of the 20th century and residential areas for people who migrated from rural areas during the high development period of the 1950s and 1960s [19]. Densely built-up areas consist of aging wooden houses on small lots of land and limited public spaces of narrow streets and parks, inhabited by elderly people, and have complicated land rights and leasehold rights. In these areas, the living environment is deteriorating since the owners are often elderly and unwilling to rebuild their houses.

The Kobe Earthquake in 1995 clearly demonstrated the vulnerability of densely built-up areas to earthquakes and fires. Immediately after the earthquake, about 4000 people died due to collapsed buildings and toppled furniture. Older, wooden buildings had a higher rate of collapse. In addition, fires broke out and spread from several locations, destroying 83 hectares and more than 7000 buildings and killing some 500 people [12].

3.2. Methodology

Semi-structured interviews were conducted in 2013 and 2014 with local government officers, experts, and private sector staff involved in programs to improve densely built-up areas. Government documents and research papers were reviewed to examine the evolution of policies and approaches. The study analyzed cases of DMZIP implemented in Tokyo.

4. Evolution of Japanese Policy to Improve the Built Environment

Japan initiated DMZIP to accelerate improvements in areas densely populated with aging wooden houses. Recognizing the critical role of these improvements in mitigating damage from major disasters, particularly in the Tokyo and Osaka metropolitan areas, the government has developed policies and programs.

4.1. Creation of DMZIP

After the 1995 Kobe Earthquake, which caused significant damage in densely built-up areas, the government began to improve the existing urban environment. The enactment of the Act on Promotion of Development of Disaster Mitigation Zones in Dense Urban Areas (Dense Urban Area Development Act) in 1997 marked a key moment. This act aims to improve fire- and earthquake-prone areas by promoting disaster management planning and collaborative efforts among homeowners. However, the requirement for unanimous consent from all residents in project areas hindered progress due to complicated consensus-building processes.

The act was amended in 2003 to create the DMZIP. This program aims to transform densely built-up areas into safe communities with integrated public spaces, such as streets and parks, and fire-resistant buildings [20]. Project implementation associations can be formed with the approval of two-thirds of the right holders to start the project. It is more flexible than other urban programs. It incorporates the approaches of land pooling and urban redevelopment programs, in which houseowners and landowners exchange their rights to land and housing complexes to be developed (

Table 1. Roles and responsibilities of actors.

Actors	Roles	Provide to the Project	Receive from the Project
Project implementation association	- Responsible for implementation - Created by residents and owners	Lands	Apartment units to live in or compensation to move out
Company	- Additional members of the association - Secretariat of the association - Project coordinator	Funds	Apartment units to be sold to the public
Local government	Project approval	Subsidy	NA

Source: Authors.

). After land and building rights are exchanged, old, vulnerable buildings are reconstructed to be fire- and earthquake-resilient. In addition, narrow streets are widened to allow fire engines and search and rescue teams to conduct disaster management activities.

A flexible approach is taken to ensure smooth implementation. The shape and boundaries of the project area need not be neatly bounded by roads and can be drawn in such a way as to exclude landowners who do not agree to the project. Local governments provide financial support to projects for two-thirds of the design and nine-tenths of the land development and construction of common facilities (Figure 1). In addition, local governments jointly develop parks and roads, which can prevent the spread of fires and ensure evacuation in the event of a fire or earthquake disaster. Project implementers can apply town planning-type rewards such as additional building volume.

The program involves the private sector as a key player. They can provide knowledge of urban development and serve as the secretariat of project implementation associations that residents formulate. They formulate financial plans, design projects, coordinate with local governments, negotiate rights for houses and land, and manage construction works.

4.2. Strengthening Government Approaches

Despite governmental efforts to reduce seismic risks, challenges persist in their implementation. The area of the most vulnerable areas decreased from about 8000 hectares in 2002 to 2219 hectares in 2021 [19,21]. These areas are mainly located in metropolitan areas, including Tokyo and Osaka (

Table 2. Risk areas of earthquakes.

City and Prefecture	Site Number	Area (ha)
Osaka Prefecture	33	1014
Yokohama City	29	355
Tokyo Metropolitan	17	247
Kyoto City	6	220
Kobe City	4	190
Nagasaki City	8	95
Kawaguchi City, Saitama	2	54
Kochi City	4	18
Urayasu City, Chiba	1	8
Tokushima Prefecture	4	5
Kadena City, Okinawa	1	2
Total	111	2219

Source: [19].

). After the 2011 GEJE, the government set a goal in 2012 to eliminate 197 high-risk areas, or 5745 hectares, throughout the country by 2020. However, the government failed to meet this target. In 2021, the government re-set the goal to eliminate these areas by 2030.

The Tokyo Metropolitan Government estimated that an earthquake in the metropolitan area would kill 9641 people and damage 204,300 houses in the worst-case scenario. The built-up area with aging wooden houses covered 8600 ha in 2020 [22].

The Tokyo Metropolitan Government has made efforts to make urban areas more resilient. The policy shift in the 1970s was from evacuation to fire resistance. The government established evacuation routes and fire shelters and distributed hazard maps to raise public awareness. In the 1980s, it began to create firebreak zones with wide roads and improve the environment in built-up areas with wooden houses.

After the 1995 Kobe Earthquake, the Tokyo government further shifted its policy to ensuring safety in hazardous areas and accelerated the improvement of built-up areas. This new policy was supported by monitoring mechanisms and the prioritization of high-risk areas. In 1996, the government formulated a 25-year master plan for disaster risk reduction and covered 6500 hectares as development areas, of which 11 sites covering 2400 hectares were selected as priority development areas [23].

After the GEJE, the Tokyo Metropolitan Government recognized the need to accelerate its efforts and in 2012 launched the “10-Year Plan to Make Dense Wooden Urban Areas Incombustible”, which calls for concentrated investment and urgent action over 10 years instead of 25 years. The plan targeted a development area of 7000 ha, which accounts for more than 10% of the city center [24]. The government steadily implemented the plan. The built-up area of old wooden houses was reduced from 16,000 hectares to 8600 hectares in 2020. Although the fireproofing rate in the development area did not reach the target of 70 percent, the rate increased from 58.4 percent to 64.0 percent in 2020. The estimated number of deaths from earthquake-related fires in the metropolitan area was reduced from 4100 to 2500, and the estimated number of damaged houses was reduced from 200,000 to 120,000 [22].

Key measures included improving build-up areas and roads to prevent the spread of fire [24]. The plan consists of 20 programs, including subsidies for consultation with residents, the dispatch of experts, reconstruction and demolition of non-combustible buildings, and measures to help residents find a place to move to. To support residents’ efforts, the government exempts the whole property tax and urban planning tax for newly constructed houses for 5 years.

As a follow-up plan, the Tokyo government formulated the Plan for a Disaster-Resilient City in 2020. This ongoing plan targets a development area of 6500 ha and a priority development area of 3350 ha in 52 locations [22]. The government spent JPY 5.8 billion and USD 39 million to improve resilience in build-up areas, including DMZIP, in 2022.

4.3. DMZIP Case Studies in Tokyo

This section reviews the DMZIP implemented in Tokyo and reveals noteworthy trends. As of 2023, seven projects have been completed and six are underway (Table 3).

In all the projects, old wooden houses were demolished. Multi-story apartments with concrete structures were constructed. The apartment building serves as a firebreak as well, contributing to the resilience of the surrounding communities.

As a representative case, the Meguro-honcho project is explained. The houses of ten landowners and three tenants were all made of wood, over 40 years old, and were likely to collapse in an earthquake, as well as being vulnerable to fire. The roads were less than two meters wide, and there was no way to reach the evacuation center. In this project, all the houses were demolished, and a new 5-story concrete apartment building was constructed. For disaster prevention, the distance from the road to the building was kept at 0.5 m.

DMZIP projects cover less than 0.7 ha, except for the 2.4 ha of the Nishishinjuku project, which is smaller than other major urban development programs. Some one-third of the land pooling projects are larger than 10 hectares, with the average project area being some 10 hectares [25]. The average size of the urban redevelopment program is about 1.4 hectares. The urban redevelopment program is designed to achieve a higher level of land use. The exceptionally large Nishisinjuku project is located in the Shinjuku business district and has been developed as commercial and residential areas with some 1000 condominium units, including two high-story buildings over 150 m tall.

Project costs range from JPY 700 million to JPY 10.2 billion, with unit costs per house ranging from JPY 28 million to JPY 66 million, excluding the Nishishinjuku project. These vary depending on geographical conditions and land use regulations. The Nishishinjuku project costs JPY 790 billion, and the unit cost is JPY 79 million. Survey and design costs are about 5 percent of total costs, compensation costs are about 20 percent, and construction costs are about 70 percent. Compared to urban redevelopment projects with an average of 50 percent for construction and 40 percent for compensation, DMZIP’s compensation costs are lower. This is because residents continue to live in the buildings constructed under DMZIP.

Project costs are covered by government subsidies and the sale of apartment units on reserved floors to new residents. Government subsidies range from 26% to 42%, with the exception of 53% for the small-scale project in Kita Ward. This is about the same as the 30% subsidy for the land pooling program and higher than the 18% subsidy for the urban redevelopment program [25]. The national government provides one-half of the subsidy, and the Tokyo metropolitan government and the wards each provide one-quarter. The remaining costs are covered by the sale of apartment units.

The private sector sees business opportunities in this scheme and participates in projects in a variety of ways. Private developers can become additional members of the project implementation association, which is made up of the owners of houses and land rights on the project site. Developers contribute to the overall profitability of the project by bearing a portion of the project cost and by purchasing condominium units for sale. In addition, as the project’s agent, they can provide technical support for project implementation that is not available to the residents.

There are several factors that determine the size of a project. To ensure the economic viability of the project, it must be large enough to cover its costs. Increasing size can increase profits. However, it will involve more right-holders, which increases the time needed to reach consensus and complete the project and reduces profitability. The smallest project of 0.06 ha took 3 years to complete, while the largest project of 2.4 ha took 8 years.

To engage the private sector, smooth consensus-building among residents is critical. The longer the consensus-building process takes, the less feasible the project becomes and the less willing the private sector is to participate.

Since the main objective of the program is to improve the city’s resilience to fire and earthquake disasters, smooth implementation takes priority over covering a larger area. Local governments expect steady implementation of even small projects to improve the situation in the wider area.

Although the original residents are properly compensated, they may not move into the new building and leave their original locations. In the Sekihara project in Itabashi Ward, 24 of the 29 residents moved out. Shinagawa, Meguro, Adachi, and Sumida wards constructed public housing that residents could rent to live nearby [10].

Table 3. Disaster mitigation zone implementation program in Tokyo.

Ward	Project	Subsidy (JPY Million) (%)	Company Contribution (JPY Million) (%)	Sales of Reserved Floors (JPY Million) (%)	Total Cost/ Unit Cost per House (JPY Million)	Area (ha)	Project Period (Year)	Completed Year	Number of Houses + Shops
Itabashi	Itabashi 3	2579 (38)	3340 (49)	879 (13)	6798/47	0.4	5	2010	139 + 6
Ada-chi	Sekihara 1	659 (31)	-	1430 (69)	2100/30	0.4	6	2013	60 + 10
Sumida	Kyojima 3	492 (33)	926 (63)	56 (4)	1474/41	0.2	4	2013	36
Shinagawa	Ebaracho-ekimae	1258 (42)	1162 (39)	75 (9)	2995/54	0.1	4	2016	55 + 14
Meguro	Meguro-honcho	214 (26)	-	596 (73)	817/39	0.06	3	2016	20 + 1
Shinagawa	Nakanobe 2	3904 (38)	5997 (59)	271 (3)	10,172/52	0.7	5	2019	195
Kita	Shimo 3–9	347 (53)	306 (47)	2 (0)	655/55	0.06	3	2021	12
Shinjuku	Nishi-shinnjuku 5	NA	NA	NA	79,300/79	2.4	8 (plan)	NA	1000
Kita	Kamojujo 1	NA	NA	NA	3000/43	0.2	>5 (plan)	NA	69
Meguro	Haramachi 1	NA	NA	NA	7900/66	0.4	5 (plan)	NA	110 + 10
Toshima	Ikebukuro Honcho3	NA	NA	NA	2500/28	0.2	4 (plan)	NA	88
Shinagawa	Higashi-nakanobe 1	NA	NA	NA	3300/55	0.2	4 (plan)	NA	60
Sumida	Higashi-mukoujima	NA	NA	NA	3800/38	0.2	4 (plan)	NA	99

Source: modified from [26].

Table 3. Disaster mitigation zone implementation program in Tokyo.

Ward	Project	Subsidy (JPY Million) (%)	Company Contribution (JPY Million) (%)	Sales of Reserved Floors (JPY Million) (%)	Total Cost/ Unit Cost per House (JPY Million)	Area (ha)	Project Period (Year)	Completed Year	Number of Houses + Shops
Itabashi	Itabashi 3	2579 (38)	3340 (49)	879 (13)	6798/47	0.4	5	2010	139 + 6
Ada-chi	Sekihara 1	659 (31)	-	1430 (69)	2100/30	0.4	6	2013	60 + 10
Sumida	Kyojima 3	492 (33)	926 (63)	56 (4)	1474/41	0.2	4	2013	36
Shinagawa	Ebaracho-ekimae	1258 (42)	1162 (39)	75 (9)	2995/54	0.1	4	2016	55 + 14
Meguro	Meguro-honcho	214 (26)	-	596 (73)	817/39	0.06	3	2016	20 + 1
Shinagawa	Nakanobe 2	3904 (38)	5997 (59)	271 (3)	10,172/52	0.7	5	2019	195
Kita	Shimo 3–9	347 (53)	306 (47)	2 (0)	655/55	0.06	3	2021	12
Shinjuku	Nishi-shinnjuku 5	NA	NA	NA	79,300/79	2.4	8 (plan)	NA	1000
Kita	Kamojujo 1	NA	NA	NA	3000/43	0.2	>5 (plan)	NA	69
Meguro	Haramachi 1	NA	NA	NA	7900/66	0.4	5 (plan)	NA	110 + 10
Toshima	Ikebukuro Honcho3	NA	NA	NA	2500/28	0.2	4 (plan)	NA	88
Shinagawa	Higashi-nakanobe 1	NA	NA	NA	3300/55	0.2	4 (plan)	NA	60
Sumida	Higashi-mukoujima	NA	NA	NA	3800/38	0.2	4 (plan)	NA	99

Source: modified from [26].

5. Discussion

Japan has created innovative approaches to resilient urban development, spurred by the imperative to mitigate the recurring devastation and casualties caused by disasters. The seismic upheaval of the Kobe Earthquake in particular, resulting in over 6000 casualties and severe damage to aging and densely populated housing, served as a catalyst for transformative initiatives. The DMZIP can be regarded as a novel scheme designed to expedite the revitalization of densely built-up areas housing old wooden structures (Figure 2). Applying methods of land pooling and urban redevelopment programs historically utilized in post-disaster and post-war recovery efforts as well as urban development, DMZIP operates within smaller, more targeted zones compared to conventional urban development programs, making urban areas resilient. Over the past two decades, the private sector has gained experience. They are more confident in developing further projects by leveraging established knowledge.

A legal framework is crucial to promoting a program, including facilitating consensus, ensuring feasibility, and achieving program objectives. The Dense Urban Area Development Act clarifies the procedures, roles, and responsibilities of government organizations, residents, and the private sector. Long-term plans with goals can guide program implementation. The Tokyo Metropolitan Government promoted DMZIP according to the long-term plans formulated. The government has revised these plans and targets according to the progress of the program and lessons learned from large-scale disasters.

A flexible framework facilitates project formulation. If right holders decide to participate in the program, they can choose to live in individual houses or in apartments that are jointly constructed. While other urban development programs require neat project boundaries surrounded by roads, DMZIP can ignore such boundaries and exclude properties whose owners do not consent to the project. Projects in Kakogawa City in Hyogo Prefecture and Kadoma City in Osaka Prefecture were formulated only by the agreed-upon owners [10]. Furthermore, agents in Tokyo cases limited the parcels that could be included in the expenditure projects.

Involving the private sector is critical to advancing any DMZIP project. Private sector involvement ensured project viability and provided urban development expertise that residents do not have.

Dense urban area improvement is less profitable than other urban development programs and requires innovative approaches to mobilize funds. Governments usually provide subsidies to cover 30–40% of project costs in Tokyo. Without subsidies, the project would not be feasible. Furthermore, Kishiwada City in Osaka Prefecture participated in the DMZIP and shared costs by building a community center and library. This helped make the project profitable [10]. Indonesian and Indian cases also stressed the importance of financing issues [4,17].

The Tokyo cases show that a simpler project arrangement is preferable to attract the private sector to DMZIP. Covering wider areas prolongs consensus-building. Including various facilities, such as parks and community centers, needs coordination with other offices. These prolong projects and reduce their profitability.

There are limitations and challenges. The urban development programs in which DMZIP is rooted were originally designed to stimulate economic activity. As such, there is a risk that DMZIP also excludes vulnerable people, such as the elderly and micro-right holders, from projects. Protecting these people is crucial to preventing gentrification. Some wards in Tokyo constructed public housing for residents who could not afford to live in apartments. Also, to support the socially vulnerable, it is necessary to consider the stability of their daily lives through social welfare services in addition to compensation.

6. Conclusions

Local communities with dense, poor, and aging housing in urban areas are more vulnerable to disaster damage, but improving such communities is difficult. These communities are often complicated by land rights and leases, and building consensus is a complex task. This study examines Japan’s evolving policies to improve urban resilience and the case of Tokyo’s DMZIP. In this program, homeowners and landowners exchange rights to reconstruct fire- and earthquake-resilient housing complexes. Japan is motivated to develop policies to avoid repeated damage from similar phenomena. The results show that the legal framework for promoting DMZIP, including funding, consensus building, responsibility sharing, and public–private partnerships, is extremely important.

The Tokyo case study showed that DMZIP is an effective way to make areas densely populated with aging wooden houses more resilient to disasters. Private sector participation is important to ensure the feasibility of the project and to promote the project by providing urban development expertise. Since the private sector focuses on project duration and scale to recoup investment, short and simple projects are desirable. Despite inherent challenges, such as lower profitability compared to traditional urban development programs, government subsidies play a pivotal role in securing project funding and fostering public–private partnerships.

Socially vulnerable groups, such as micro-right holders and the elderly, are at risk of not being able to live in the condominiums to be built and being forced to move out of their original areas. Consideration should be given to protecting their daily lives and providing social welfare services.

Japan’s experience with DMZIP offers valuable insights into effective disaster-resilient urban development strategies for developing countries facing urbanization-induced disaster risks with poor built environments. It emphasizes the importance of collaborative partnerships, flexible frameworks, and proactive measures to create safer and more resilient urban environments in the face of evolving disasters. Governments should develop laws and systems for public–private partnerships that clarify the division of costs and responsibilities between the public and private sectors.