The Iidabashi Station East District Type 1 Urban Redevelopment Project is a large-scale project in Chiyoda City to develop a 26-story mixed-use tower standing approximately 130 meters tall. As of March 2026, the rights conversion plan remains unapproved and construction has not yet begun, representing a significant delay from the originally planned completion date of November 2026. In July 2025, the "Iidabashi Station Area Infrastructure Development Plan" was officially formulated, finally bringing clarity to the structural reasons behind the schedule delay and the overall vision for integrated urban development across three districts surrounding the station.
Project Overview of the Iidabashi Station East District Redevelopment
The Iidabashi Station East District Type 1 Urban Redevelopment Project is located at Iidabashi 3-chome, Block 6 and adjacent areas in Chiyoda City, covering a project area of approximately 0.7 hectares. Chiyoda City approved the urban planning decision in June 2021, and the following year in October 2022, the Tokyo Metropolitan Government authorized the establishment of the Iidabashi Station East District Urban Redevelopment Association. The total project cost amounts to approximately ¥36.7 billion.
The planned building comprises 2 basement levels, 26 above-ground floors, and 2 penthouse levels, reaching a height of approximately 130 meters with a total floor area of roughly 46,500 m². With a floor area ratio of 1,100%, the high-density development features commercial and public facilities on the lower floors, office space exceeding approximately 1,400 m² per floor on the mid-level floors (3rd to 20th), and residential units on the upper floors (22nd to 26th). The four participating association members are Mitsubishi Estate, Mitsubishi Estate Residence, Daiwa House Industry, and Shimizu Corporation. Shimizu Corporation has been involved as a project cooperator since 2011, while Mitsubishi Estate joined the preparatory association in 2017, reflecting a long history of organizational development.
Behind the Schedule Delay — Why Construction Has Not Progressed
The original plan envisioned a construction start in September 2023 with completion in November 2026. However, as of March 2026, approval for the rights conversion plan has still not been obtained, and demolition of existing buildings has not even begun. The association has made no official announcement regarding a new completion date, making a significant delay a certainty.
The delay stems from the complex infrastructure surrounding Iidabashi Station. As a terminal served by five lines — JR Chuo-Sobu Line, Tokyo Metro Tozai, Yurakucho, and Namboku Lines, and the Toei Oedo Line — a dense web of railway infrastructure both above and below ground surrounds the station. Because construction of the redevelopment building would occur in close physical proximity to these railway facilities, technical coordination with JR East and Tokyo Metro is essential. Moreover, this extends beyond simple bilateral negotiations, requiring broad-based consensus among multiple administrative bodies including the Tokyo Metropolitan Government, Chiyoda City, Shinjuku City, and Bunkyo City.
For this reason, the construction plan could not be finalized through the redevelopment project alone — it was necessary to wait until plans for urban infrastructure such as the station plaza and pedestrian decks were established. That infrastructure development plan was released as a draft in May 2025 and officially formulated in July of the same year, finally providing the foundation for coordination.
Formulation of the Iidabashi Station Area Infrastructure Development Plan (July 2025)
The "Iidabashi Station Area Infrastructure Development Plan," published by the Tokyo Metropolitan Government on July 30, 2025, was formulated by the "Iidabashi Station Area Infrastructure Development Promotion Council," which includes the Tokyo Metropolitan Government, Chiyoda City, Shinjuku City, Bunkyo City, JR East, and Tokyo Metro. This plan defines urban infrastructure improvements to enhance connectivity, convenience, and safety around the station.
The plan covers four main areas of development. First, expanding pedestrian space beneath the JR Iidabashi Station East Exit elevated tracks to improve passenger flow. Second, developing a three-dimensional station plaza including improvements to the Tokyo Metro A2 entrance. Third, constructing a new pedestrian deck connecting the station's east exit to the Bunkyo City area. Fourth, renovating the A4 entrance. These three priority projects target completion by fiscal year 2033, bringing into view an integrated vision of the redevelopment building and station infrastructure.
If anything, the delay can be viewed positively: by synchronizing with the infrastructure development plan, the result will be a higher-quality urban environment upon completion. Rather than the redevelopment building being completed in isolation, the integrated development of pedestrian decks, station plazas, and elevated track underspaces will dramatically improve accessibility for neighboring offices and residences. Looking at multiple redevelopment cases in central Tokyo, districts where transportation infrastructure and redevelopment buildings work in concert tend to see more stable increases in real estate value after completion.
Integrated Urban Development Across Three Districts Around Iidabashi Station
The area around Iidabashi Station involves coordinated urban development not only in the East District (this project) but across multiple districts.
Iidabashi Station Central District received its urban planning decision in June 2025 and plans a mixed-use facility with 3 basement levels, 21 above-ground floors, and a height of approximately 108 meters. Targeting completion in the 2030s, it is located in the Chiyoda City area like the East District. With the East District (26 floors, approximately 130 m) and the Central District (21 floors, approximately 108 m) standing side by side, two high-rise mixed-use towers will emerge in the Iidabashi East Exit area.
Iidabashi Station Front District is under consideration on the Shinjuku City side, with potential to connect to urban development around the west exit. As the East District and Central District on the east side and the Station Front District on the west side are developed, a pedestrian circulation network spanning both sides of Iidabashi Station will take shape, enhancing the value of the entire area.
Compared to trends among major Tokyo redevelopment projects, Iidabashi stands out for its phased development with coordination across multiple districts, promising a more complex and layered enhancement of regional value than standalone redevelopment projects.
Impact on the Real Estate Market and Actions for Property Owners
The impact of the Iidabashi Station East District redevelopment on the real estate market upon completion can be analyzed from three perspectives.
From an office demand perspective, the supply of large floor plates exceeding approximately 1,400 m² per floor is noteworthy. The introduction of large-scale office space meeting central five-ward standards into the Iidabashi area — traditionally characterized by clusters of small to mid-sized buildings — could attract relocation demand from IT and consulting firms. However, with the expected completion pushed back to the early 2030s, the impact on existing buildings will remain limited for the time being.
From a residential demand perspective, the upper-floor residences carry scarcity value as tower units with a Chiyoda City address. Tower apartment supply within Chiyoda City is extremely limited in absolute numbers, and Iidabashi's position close to both Chiyoda and Bunkyo Cities is expected to sustain strong demand from affluent buyers and expatriates working for foreign companies.
From a commercial and public facilities perspective, the completion of connections via pedestrian decks and station plazas will create a station-adjacent commercial hub. For owners of existing office and residential properties in the surrounding area, an environment of sustained upward pressure on rental levels is anticipated.
This is precisely why it is important to closely monitor the timing of the rights conversion plan approval and the announcement of new construction and completion schedules. Since the surrounding area is expected to undergo rapid change once approval is granted, maintaining an active information-gathering posture from this point forward is essential.
INA&Associates' Perspective
Iidabashi is a rare location that combines waterfront views along the Imperial Palace outer moat with the transportation convenience of five JR and Tokyo Metro lines converging at a single station. At first glance, the schedule delay may appear to be negative news, but we are observing the situation with cautious optimism.
Through the formulation of the infrastructure development plan, what will ultimately be realized is not merely a standalone redevelopment building, but a comprehensive urban environment integrating pedestrian decks, station plazas, elevated track underspaces, and multiple high-rise towers. This follows the same mechanism of "elevating an entire district" seen around Toranomon Hills and Shibuya Station.
We believe the practical turning point for surrounding real estate will come when the rights conversion plan receives approval. Once construction begins, the effects will start to ripple through rental rates and property valuations in neighboring areas. Making strategic decisions now with an eye toward Iidabashi in the 2030s is the critical challenge for those who hold assets in this area.
Summary
The Iidabashi Station East District Type 1 Urban Redevelopment Project is a large-scale initiative to develop a 26-story mixed-use building at a total cost of approximately ¥36.7 billion. Originally scheduled for completion in November 2026, it has been delayed due to the complex station structure and the need for coordination among numerous stakeholders, with the rights conversion plan still awaiting approval and construction yet to begin. The official formulation of the infrastructure development plan in July 2025 has helped clarify the structural reasons behind the delay while bringing the overall vision for integrated urban development across the East District, Central District, and Station Front District into focus. Priority infrastructure projects target completion by fiscal year 2033, and Iidabashi's urban landscape is expected to undergo a major transformation over the coming decade.
Frequently Asked Questions (FAQ)
Q1. When will the Iidabashi Station East District redevelopment be completed?
A. The original target was completion in November 2026, but as of March 2026, the project has been significantly delayed because the rights conversion plan remains unapproved. No new completion date has been announced. Given that the priority infrastructure projects target completion by fiscal year 2033, completion in the early 2030s is anticipated, though the precise timeline will become clear after the rights conversion plan is approved.
Q2. Which developers are involved in the Iidabashi Station East District redevelopment?
A. The four participating association members are Mitsubishi Estate, Mitsubishi Estate Residence, Daiwa House Industry, and Shimizu Corporation. Shimizu Corporation has been involved as a project cooperator since 2011, and Mitsubishi Estate joined the preparatory association in 2017.
Q3. What other redevelopment projects are underway around Iidabashi Station?
A. In addition to the East District, the Iidabashi Station Central District (21 floors, approximately 108 m tall) received its urban planning decision in June 2025 and is targeting completion in the 2030s. Urban development studies are also progressing for the Iidabashi Station Front District on the Shinjuku City side. The coordination of these three districts is expected to create a highly connected area linking both sides of the station.
Q4. How will the area in front of Iidabashi Station change?
A. Under the "Iidabashi Station Area Infrastructure Development Plan" formulated in July 2025, planned improvements include expanding pedestrian space beneath the JR East Exit elevated tracks, developing a three-dimensional station plaza with improvements to the Tokyo Metro A2 entrance, constructing a new pedestrian deck connecting the east exit to the Bunkyo City area, and renovating the A4 entrance. The three priority projects target completion by fiscal year 2033.
References
- Tokyo Metropolitan Government Bureau of Urban Development, "Iidabashi Station East District Type 1 Urban Redevelopment Project"
- Shimizu Corporation, "Establishment of Redevelopment Association for Iidabashi Station East District Type 1 Urban Redevelopment Project" (October 12, 2022)
- Mitsubishi Estate, "Notice of Establishment Authorization for Iidabashi Station East District Type 1 Urban Redevelopment Project Redevelopment Association" (October 12, 2022)
- Tokyo Metropolitan Government, "Formulation of the Iidabashi Station Area Infrastructure Development Plan" (July 30, 2025)
- Tokyo Metropolitan Government Bureau of Urban Development, "Iidabashi Station Area Infrastructure Development Promotion Council"
- Chiyoda City, "Urban Development in the Iidabashi-Fujimi Area"
