Press Conference Regarding Formal Announcement on Acquisition(PDF : 3.1MB),
Preservation, and Utilization of the Former Kagawa Prefectural Gymnasium
(23 July 2025)

Kagawa Prefectural Gymnasium: Preliminary Renovation Plan
23th July 2025
Kagawa Prefectural Gymnasium Rebirth Committee

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Kagawa Prefectural Gymnasium: Preliminary Renovation Plan
Explanation Flow

１．Summary

New Proposal for the Revitalization and Utilization of Kagawa Prefectural Gymnasium

• The Kagawa Prefectural Gymnasium, designed by Kenzo Tange, faces demolition due to aging and seismic deficiencies.

• However, its cultural value is gaining re-evaluation both domestically and internationally.

• A private proposal offers full renovation and utilization as a hotel, entirely self-funded.This presents a realistic and sustainable path for revitalization, differing from past assumptions.

Core of the Proposal

• The core of the proposal involves private funding for seismic retrofitting and design preservation.

• It includes converting the building into an accommodation facility and acquiring the land and building from the prefecture.

Expected Benefits

• Expected benefits include job creation, tourism promotion, and cultural asset inheritance.

• The plan avoids the prefecture's demolition costs, estimated at approximately 1.1 billion yen.

Our Request

• We request consideration for delaying demolition due to changed premises and a cost-free preservation option.

２．Reconfirming Background and Current Status

Three failed bids for seismic retrofitting led to the abandonment of renovation. Various utilization plans were explored but no concrete proposals materialized.

We were forced to demolish it because no effective use for it could be found.

• Demolition was decided due to unmet utilization proposals and structural issues. 

• The building faces seismic inadequacy, aging, and a lack of defined purpose.

3．Architectural Value and Cultural Significance

Kenzo Tange's architectural masterpieces have the potential to become future World Heritage Sites, and there are many calls from around the world for their preservation.

pinnacle of its time : The gymnasium, designed by Kenzo Tange, holds international architectural significance.
– It is a valuable comprehensive art piece, integrating designs by Isamu Kenmochi and Tadashi Yamamoto.
– It is considered a potential World Heritage site, garnering global preservation calls.

a true integration of technology and design : The design integrates advanced technology with aesthetic principles of its time.
– It merges traditional Japanese boat aesthetics with modernist structural rationality.

many voices calling for its preservation : Numerous influential international organizations advocate for its preservation.
– Harvard University Graduate School, Museum of Modern Art in New York, University of Illinois, and others.

４．Change in Judgment Premise

The premise for demolition has changed with a new private-funded preservation and revitalization plan.

Previously

• It is difficult for the prefecture to carry out the seismic reinforcement work.

• no effective utilization plan proposed

• public funding was deemed necessary for preservation.

Now(2025)

• The private sector intends to fully self-fund the seismic reinforcement and revitalization.

• new proposal includes a concrete plan for profitable operations, such as accommodation.

• The prefecture can now preserve the building without incurring financial burdens.

5．Private Sector Revitalization Plan

Given Kagawa Prefecture's master plan and recent trends, we'll develop an accommodation facility in Takamatsu that will serve as a new cultural hub and promote local exchange.

• Kagawa Prefecture's high-level plans : urban revitalization through tourism and culture

• Issues : attracting visitors during non-Setouchi Triennale years

• Potential : modern architectural masterpiece by Kenzo Tange

We will utilize the space as a hub for art, architecture, and tourism, drawing in visitors and fostering exchange.
We'll also open up the plaza to encourage interaction with local residents.

Reference）Private Sector Revitalization Plan: Scheme Diagram

We have reached out to highly accomplished players across various industries, and several companies are already considering participation.
Our aim is a 100% private-funded revitalization, transforming the facility into a profitable accommodation-centric establishment while preserving its cultural value.

注1）具体の企業名の提示は、現時点での外部への情報流出を懸念し差し控えさせて頂けます
※）事業者名は、現時点での想定であり、変更の可能性があります

Proposal 1: Hotel with Book Lounge

Planning a multi-purpose complex for tourists and local residents, combining accommodation, knowledge, culture, and architecture.
– The first and second floors will house a lifestyle hotel. On the third floor and above, there will be a spacious area featuring a book lounge filled with books, a cafe, and an art space.

Please note that the numbers and conditions above may change upon further detailed review.

Proposal 2: Single-Building Hotel Plan

This plan proposes converting the building into a single accommodation facility, primarily targeting inbound tourists. We aim to create a rich interior space by adding new flooring and opening up the rooftop, allowing for the creation of unique "only here" scenic views in the remaining areas.

• The first floor will house the back-of-house operations, a restaurant, and the lobby.

• The second floor and above will feature various sizes of guest rooms.

• By creating a large opening in the central part of the building and developing a light court, we will generate new open spaces.

Please note that the numbers and conditions above may change upon further detailed review.

Reference）Confirmation of Business Viability

Even with Proposal 1, approximately 100 million yen in operating profit is expected. This level is considered sufficient for private businesses to participate and ensure business continuity.

Annual Business Balance Overview（million yen/annual year）

Note 1: For the hotel, we're assuming 20 rooms, an Average Daily Rate (ADR) of ¥35,000, and a 70% occupancy rate, leading to an estimated revenue of ¥180 million. The book lounge and cafe are projected to have 700,000 visitors annually, including during events, with an average spend of ¥500 per person, resulting in ¥350 million in revenue.

Note 2: For the hotel, we're assuming 60 rooms, an ADR of ¥60,000, and a 70% occupancy rate, leading to an estimated revenue of ¥950 million. An additional ¥500 million in revenue is anticipated from food and beverage, spa services, etc. Please be aware that both proposals are subject to change based on future detailed business reviews. Furthermore, if support being considered by the Agency for Cultural Affairs' Cultural Economy Division, Architectural Culture Working Group is received, the financial outlook will improve, and we anticipate greater participation from various companies.

Reference）Why We Aim for "Revitalization" Instead of Just "Preservation"

The objective is "regeneration" rather than mere "preservation" to ensure financial viability.

Business Balance Overview（million yen/annual year）

Note 1: For preservation, the calculation is based on an admission fee of ¥500 per person for architectural viewing, with an annual attendance of 3,000 visitors. Maintenance costs are estimated at ¥10 million per year, and seismic renovation costs are depreciated over 50 years. For revitalization, the figures are based on Proposal 1.

Please note: The above figures and conditions are current assumptions and may change upon further detailed review.

Reference）Why We Aim for "Revitalization" Instead of Just "Preservation"

For the revitalization, we will utilize architect Shigeru Aoki's “refining architecture” techniques.

Refining Architecture: Shigeru Aoki's Approach to Building Revitalization

Refining architecture is a renovation method championed by architect Shigeru Aoki, developed over 25 years. This unique approach, backed by extensive experience and specialized techniques, can be summarized by these five core principles:

1. New-Build Quality: The finished building, both inside and out, will be equivalent to or even surpass the quality of new construction.

2. Cost-Effective: Achieve this high quality at just 60-70% of the cost of building new.

3. Flexible Use: The building's purpose can be changed to suit new needs.

4. Seismic Compliance: Enhanced earthquake resistance ensures the building meets current laws and the Act on Promotion of Seismic Retrofit.

5. Eco-Friendly: Minimal waste is generated, making the process environmentally sound.

Reference）Approach to Seismic Renovation

Seismic retrofitting costs are reduced through private conversion and technological advancements.

Previous Approach (2014) the estimated cost for seismic renovation was “1.8 billion yen”

Required Performance for Public Buildings

Bearing Wall

• equire load-bearing walls that meet Seismic Resistance Class III, Level 2.

• ※IS value of approximately 0.8.

Ground

• Due to the heavy load of the building, there's a possibility of liquefaction

• ※gravitational acceleration≧400GAL

Solutions

suspended roof

• effective methods for this highly difficult construction were not available with the technology of the day.

Earthquake resistance

• In 2D analysis, it's difficult to clearly understand the flow of forces, which often leads to overly conservative designs.

　　　　　　　　　　　　　　　　　　↓

New Approach (2025) the estimated cost for seismic renovation was “0.6-1 billion yen”

Required Performance for Private Buildings

Bearing Wall

• Load-bearing walls meeting Seismic Resistance Class I to II, Level 2

Ground

• Since heavy load-bearing walls are not necessary, the possibility of liquefaction is low.

• ※gravitational acceleration≧200LGAL3

Solutions

suspended roof

• – Reinforcement is possible with just a double layer of carbon fiber coating.

Earthquake resistance

• By using 3D analysis, we can optimize the load-bearing walls to achieve both seismic resistance and cost-effectiveness.

Note 1 : ** As we haven't yet conducted an internal survey, concrete deterioration and other factors will be thoroughly examined in future detailed studies. Also, the required load varies depending on the building's use, so this may change after further detailed review.

Note 2 : 
*Seismic Resistance Class 1** means the building will not collapse or crumble from seismic forces equivalent to an earthquake occurring once every few hundred years (seismic intensity 6 to 7).
*Seismic Resistance Class 2** can withstand seismic forces 1.25 times that of Class 1.
*Seismic Resistance Class 3** can withstand seismic forces 1.5 times that of Class 1.

Note 3 : The anticipated seismic intensity for Takamatsu City during a Nankai Trough earthquake is estimated at *weak seismic intensity 6. Therefore, a gravitational acceleration of 200 GAL**, equivalent to weak seismic intensity 6, is assumed.

Reference）Trends at the Agency for Cultural Affairs

The challenges in preserving architectural heritage largely stem from economic factors in addition to aging infrastructure. Recognizing this, the Agency for Cultural Affairs is starting to move towards providing financial support not only for "preservation" but also for "revitalization" of buildings.

• The primary reasons for the loss of architectural heritage are largely due to aging and deterioration, but economic factors also play a significant role.

• Organizing and enhancing economic support for the continuation of architectural heritage is a key discussion point for this Working Group.

• The former Kagawa Prefectural Gymnasium is also being cited as an example for this preservation model.

-Source: Materials distributed by the Agency for Cultural Affairs, Council for Cultural Affairs, Cultural Economy Division, Architectural Culture Working Group.

6. Anticipated Effects (Economy and Regional Revitalization)

The utilization as an accommodation facility is projected to generate over 3-6 billion yen in initial investment.

It is expected to contribute approximately 0.5 billion yen annually to the local economy.

Please note 1: The business balance is based on Proposals 1 and 2. Regional expenditure by tourists is estimated assuming that approximately 10,000 to 30,000 overnight guests will spend 10,000 yen each on food, transportation, and retail purchases in the city.

Please note that the numbers and conditions above may change upon further detailed review.

In the long term, it will enhance regional tourism by connecting with other cultural resources.

7. Proposal for Land and Building Handling

The land is proposed for a paid transfer (sale) and the building for a free or low-cost transfer.

*The above figures and conditions are subject to change based on further detailed consideration.

The land is proposed for a paid transfer

• The land retains significant economic value, making a paid transfer appropriate.

• This scheme aligns with the principle of property valuation based on actual value.

The building for a free or low-cost transfer.

• The building's book value is zero, reflecting its depreciated asset status.

• The building currently does not meet seismic standards and requires full renovation by the private acquirer.

The cost for prefecture

• – The prefecture incurs no financial burden and avoids 1.1 billion yen in demolition costs.

8．Estimated Schedule for Seismic Reinforcement

Seismic reinforcement work is projected to be completed by fiscal year 2027.
This completion timeline is concurrent with or earlier than the planned demolition completion.

Please note that the above schedule is a tentative plan at this stage and may be subject to change upon further detailed review.

9．Requests to Kagawa Prefecture

• We urge the prefecture to acknowledge the changed premise for demolition.

• We request reconsideration of a path to preserve "Kagawa's heritage" without

  public expense.

• We advocate for choosing "revitalization and utilization" as a valuable option

  for future generations.

Request for Signatures to Preserve and Revitalise the Former Kagawa Prefectural Gymnasium
Transforming a World-Class Architectural Landmark into a Sustainable Cultural Hub with the Power of Kagawa

The private organisation ‘Old Kagawa Prefectural Gymnasium Revitalisation Committee’ has been established to preserve and revitalise the old Kagawa Prefectural Gymnasium, designed by world-renowned architect Kenzo Tange and affectionately known as the ‘Ship Gymnasium.’ The committee, with the support of companies such as “Nomura Kogei Co., Ltd.,” which originated in Kagawa, has presented a concrete plan to revitalise the building as a hotel and cultural exchange facility, including acquisition from the prefecture and seismic retrofitting, at a maximum cost of 6 billion yen. The prefecture can achieve both the preservation of a cultural building and the revitalisation of the local economy without any financial burden, including the 1.1 billion yen demolition cost. The goal is to achieve sustainable utilisation without relying on prefectural finances by leveraging private funds. 

This building is a masterpiece of post-war Japanese architecture highly regarded internationally, such as by Harvard University and the Museum of Modern Art (MoMA) in New York. To pave the way for preserving it for future generations rather than demolishing it, the voices of many people are urgently needed at this very moment.

Please join us in signing the petition to ‘preserve and revitalise’ this cultural heritage. Your signature will be the power to leave this architecture, which Kagawa can proudly present to the world, for future generations.

Sign the petition here: 
https://change.org/savetheboatgym

Inquiries: 
Former Kagawa Prefectural Gymnasium Revitalisation Committee (Contact: Uesugi) 
Official Website : https://kpg-rebirth.jp/
E-mail: info@kpg-rebirth.jp 
Tel/Fax: +81-(0)87-834-3489 
Office: 1838-65 Mineyama-cho, Takamatsu City, Kagawa Prefecture, Japan (Nagata Keita Architectural Elements) 
X: (@kpg_rebirth) https://x.com/kpg_rebirth 
Instagram: https://www.instagram.com/kpg_rebirth/
YouTube: https://www.youtube.com/@TheAxisKagawa