Leave the repairs and renovations of condominiums and apartments in Izumi, Yokohama City to Kakeru Koumuten Co., Ltd.!

Large-Scale Renovations for Condominiums, Apartments, and Buildings in Izumi Ward, Yokohama

Large-scale renovation work that can be handled in Izumi Ward, Yokohama

Large-scale renovations are not just “exterior painting” or “waterproofing,” but a comprehensive repair of the entire building’s deterioration while scaffolding is in place. At Kakeru Koumuten, we can handle all of the following work in-house, ensuring clear responsibility and coordination of the process.

Scope of Major Repairs Determined by Building Diagnosis

It is not always necessary to carry out all the above works. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten Co., Ltd., we conduct a free on-site survey to confirm the items below, compile them into a deterioration diagnosis report with photos, and propose the scope of work.

Reasons Kakeru Koumuten is Chosen for Large-Scale Renovations in Izumi Ward, Yokohama City

The reason why we can be entrusted with large-scale repairs in Izumi Ward is partly because “Kakeru Koumuten has a base in Yokohama City”, but also due to our “unique initiatives in large-scale repair work that cannot be imitated by other companies”, which have received high praise from many customers.

1. Equipment Specialized for Exterior Renovations

At Kakeru Koumuten, we have prepared the following warehouses and material storage areas to provide low-cost, high-quality exterior wall painting and waterproofing work for large-scale repairs. We have established five bases centered around Yokohama City for material storage and showrooms.

In-house Scaffolding Materials

We own the scaffolding materials necessary for temporary scaffolding required for large-scale repairs and can assemble the scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can cut costs on scaffolding work and provide quick and flexible responses.
We have approximately enough scaffolding materials for 100 single-family homes!

Storage of Materials in Our Large Warehouse

We store paints and substrate repair materials used for exterior renovations. By ordering a large quantity of materials at once, we can procure materials at a lower cost! Additionally, we always have stock available, allowing us to respond quickly in emergencies!

In-house Waste Separation

During large-scale repairs, various waste materials such as leftover paint, metal, and wood are generated. At Kakeru Koumuten, we sort and recycle waste materials in-house, leading to cost reductions in waste disposal.

Showroom Dedicated to Exterior Renovations

In the showroom, not only can you have meetings, but you can also check actual samples and colors of exterior materials. Color simulations for exterior wall painting and heat insulation tests using a heat insulation testing machine are also available!

2. Cost Reduction through In-House Management and Construction

One of Kakeru Koumuten’s major strengths is in-house management and construction.

From inquiry to project completion, everything is managed by Kakeru Koumuten in a consistent system, allowing for high-quality large-scale repairs at reduced costs. Additionally, one representative will handle everything from the estimate to project completion. Since the person in charge does not change, whether it’s the sales representative or the construction management representative, smooth communication is possible.

We can handle everything from temporary scaffolding installation to exterior wall painting, substrate repairs, waterproofing work, and tile repairs with complete in-house construction! Those with specialized knowledge and experience will conduct inspections and actual construction for each process!

3. Obtaining Various Permits and Skilled Workers

We have obtained construction industry licenses and permits for industrial waste collection and transportation! We also have nationally certified sheet metal and painting skilled workers, and we are confident in our construction techniques. We can also handle large-scale roofing work for factories! We have qualified personnel for asbestos work supervisors and investigators of buildings containing asbestos materials, so we can handle and conduct preliminary investigations of roofing materials containing asbestos.

4. Warranty and Aftercare

Most large-scale repair works, including “painting work,” “substrate repair work,” and “waterproofing work,” come with a warranty!
Aftercare maintenance is available annually, and we send out notification DM every year.

5. Flexible and Prompt Response

Our company is equipped to handle various troubles and situations related to apartments and condominiums.

We can also address exterior walls and rooftops that cannot be checked from high places using a drone! During rain leak investigations, we can use a thermal imaging camera to help identify the cause of the leaks!

We will respond according to your wishes. We also accept emergency measures for sudden rain leaks! We will promptly respond to urgent requests or emergencies!

6. Human Resource Development

Our staff create various models to improve their skills and conduct practical training. Since different sites require various processing and techniques, we regularly provide skill enhancement education to ensure each staff member can respond effectively. We also educate on points to be cautious of and areas to check during each stage of large-scale repair work.

7. Consideration for Residents and Neighbors

During large-scale renovation work, we will not only notify residents and greet nearby residents, but also install a bulletin board at the entrance to display the construction schedule and notices! Additionally, we will thoroughly educate visitors on proper manners to minimize any inconvenience to residents and neighbors.

8. Strict Quality Control

Each process will be inspected by a responsible person, and detailed construction photos will be taken. We use film thickness inspection devices and check sheets to ensure that there are no oversights in inspections. During exterior wall painting and waterproofing work, we confirm the quantity of used paint cans to ensure that the specified amount of paint is used, and we prevent construction defects by ordering paint directly from our company. Of course, we will also take photos of the used paint and report them.

9. Exterior Wall Painting Color Simulation

9-1 Self Color Simulation

The simulations we create can be done using actual photos of your apartment or building!You can also perform simulations on your smartphone or computer. By simulating and then changing to a two-tone color or altering the image, we hope to enhance the stylish appearance and increase occupancy rates! Of course, we can also arrange paint samples for actual color confirmation.

* There are areas in Izumi Ward where building agreements and district plans are established, and the color of the exterior walls may need to harmonize with the surroundings. Having a color simulation screen will help facilitate explanations at community meetings and general meetings.

9-2 Confirm the Actual Color with a Test Paint!

You can order samples of the paint you are considering and conduct a test paint on your exterior wall. By doing a test paint, you can confirm the actual color and gloss!

9-3 Exterior Renovation Simulation

Exterior simulations for apartments and condominiums are also possible!
・Exterior wall color simulation (two-tone colors are also possible)
・Simulation for when metal siding is applied
・Simulation for when accent materials such as cornices and louvers are used
・Simulation for roof painting and roof replacement work

With the exterior renovation simulation, you can significantly reduce the risk of failure in image changes! We hope that renovating the appearance of apartments and condominiums will help increase occupancy rates.

Cost Estimates for Major Repairs in Yokohama City, Izumi Ward

The cost of major repairs varies greatly depending on the size of the building, the degree of deterioration, the scope of work, and the materials used. First, please refer to the national average based on public statistics, then to our company’s estimates based on construction performance by scale, and finally to examples of unit prices for each project.

The national average for condominiums is 750,000 to 1,500,000 yen per unit

According to a survey conducted by the Ministry of Land, Infrastructure, Transport and Tourism, which collected 818 construction cases (FY 2021), the cost of major repairs is concentrated at approximately 70% in the range of 750,000 to 1,500,000 yen per unit, with the most common price range being 1,000,000 to 1,250,000 yen. Yokohama City also indicates on its official website that the cost is “approximately 1,000,000 to 1,300,000 yen per unit.” Note that the amounts in this survey do not include consumption tax and common temporary construction costs, so they differ from the current total construction costs including tax.

Source: Ministry of Land, Infrastructure, Transport and Tourism “Survey on Large-Scale Renovation Work for Condominiums in FY2021” (200 companies, 818 cases) / Yokohama City “Market Prices for Large-Scale Renovation Costs and How to Address Shortfalls in Repair Reserve Funds” *Amounts do not include consumption tax or common temporary construction costs. Percentages may not total 100% due to rounding and non-responses.

Breakdown of Construction Costs (What the Money is Spent On)

Source: Ministry of Land, Infrastructure, Transport and Tourism “Survey on Large-Scale Renovation Work for Condominiums in FY2021” (Second aggregation of large-scale renovation work. Overall average is 59.0% for construction-related work, 22.3% for temporary construction, and 9.9% for miscellaneous expenses). *The total does not equal 100% because it includes equipment-related work, exterior works, and others. This is an average value and not a criterion for judging the appropriateness of individual estimates.

Cost Estimates by Building Size (Scaffolding, Substrate Repair, Exterior Painting, Waterproofing, Sealing)

*The above estimates are based on Kakeru Koumuten’s construction records and may vary depending on the presence of roofing work, metal work, plumbing, etc. For apartments, please also consider the national statistics above (750,000 – 1,500,000 JPY per unit) multiplied by the number of units as a reference.

Breakdown of Costs for Scaffolding, Substrate Repair, Exterior Walls, and Waterproofing

The estimate for large-scale repairs is broadly divided into “Scaffolding,” “Substrate Repair,” “Sealing,” “Exterior Painting,” “Waterproofing,” and “Miscellaneous Expenses.” Before comparing total amounts, please check what each item includes, how much, and at what cost.

Unit Price Examples for Repair Work

*Costs and warranty periods vary depending on shape, quantity, substrate condition, and type of materials. If you would like a detailed estimate, please feel free to contact us. Estimates are completely free.

Select Paint and Waterproofing Grades Based on “Years Until Next Repair”

“Good paint does not equal the right choice.” The best way to choose is to align when you will conduct the next major repair with the lifespan of the materials to avoid waste.

*The estimated lifespan is a general guideline and may vary depending on sunlight, location, and substrate condition. In areas like Izumi Ward, where there is a lot of greenery and shade, choosing paints with anti-algae and anti-mold properties can change durability.

Guidelines for Repair Reserve Funds and Options When Insufficient

The Ministry of Land, Infrastructure, Transport and Tourism guidelines indicate the estimated repair reserve fund on a monthly basis per unit area. Additional charges are required if there is a mechanical parking lot.

Source: Ministry of Land, Infrastructure, Transport and Tourism “Guidelines for Repair Reserve Funds for Condominiums” (Reiwa 6, June revision, PDF) / National average is 13,378 JPY per unit per month (Reiwa 5 Fiscal Year Comprehensive Survey of Condominiums)

In the Reiwa 5 Fiscal Year Comprehensive Survey of Condominiums, 36.6% of management associations responded that “the repair reserve fund is insufficient compared to the plan.” There are four main options when insufficient.

Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Izumi Ward, Yokohama City

Both Yokohama City and Kanagawa Prefecture do not have subsidies specifically for large-scale renovation work. The available options can be broadly categorized into four types. The eligibility and application status of the systems may change even during the fiscal year, so please be sure to confirm with our company or the respective offices before contracting or starting work.（As of October 7, 2026）

① Condominium Longevity Promotion Tax System (Reduction of Fixed Property Tax)

If large-scale repairs (including exterior painting, floor waterproofing, and roof waterproofing) that contribute to the longevity of certain qualifying condominiums are carried out, the fixed property tax amount for the following year will be reduced by half (up to 100㎡ equivalent per unit; urban planning tax is not included).

* The national leaflet shows the range of reduction rates as a nationwide system. The reduction rate in Yokohama City is 50%.

② Support for Apartment Management in Yokohama City (For Management Associations, Start Here)

The support system in Yokohama City is mostly based on registration in the “Yokohama City Apartment Registration System” (free). Management associations that are not yet registered should start here.

Source: Yokohama City “Support and Subsidy System List by Concerns for Condominium Management Associations” / Long-term Repair Plan Creation Promotion Model Project / Condominium Advisor Dispatch / Yokohama Condominium Portal

③ Management Plan Certification System (Entrance to Tax and Interest Rate Benefits)

This is a system certified by Yokohama City. Once certified, it allows for a 0.2% reduction in the loan interest rate from the Japan Housing Finance Agency, preferential interest rates for Flat 35, and meets one of the requirements for the long-life promotion tax system (certification alone does not guarantee tax reduction). The main criteria include holding general meetings at least once a year, organizing management regulations, separate accounting for management fees and repair reserve funds, ensuring that the total amount of arrears is within 10% of the total, and “having created or reviewed a long-term repair plan that includes large-scale repair work at least twice and has a planning period of over 30 years within the last 7 years.”

*Fees include a system usage fee of 10,000 yen + a city application fee of 3,900 yen, among others. It takes 2 to 3 months from application to certification. The validity period of the certification is 5 years.

④ National Energy Conservation Support | Housing Energy Conservation 2026 Campaign

Changes for Fiscal Year 2026The “Child-Rearing Green Housing Support Project” for Fiscal Year 2025 has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Additionally, the “Long-Term Quality Housing Renovation Promotion Project” will end in Fiscal Year 7 and will not be implemented in Fiscal Year 8. Please be careful not to create financial plans based on outdated information.

Mirai Eco Housing 2026 Project

Advanced Window Renovation 2026 Project

⑤ Kanagawa Prefecture Subsidies (Applications for the 2026 Fiscal Year Have Ended)

* The Existing Housing Energy Efficiency Renovation Subsidy does not cover common areas of rental apartments or units not occupied by the owner.

⑥ Financing System (Housing Finance Agency Condominium Sumairu Loan)

If the management association borrows funds for large-scale repairs, it can utilize the Housing Finance Agency’s “Condominium Common Area Renovation Loan (Condominium Sumairu Loan).”

Source: Housing Finance Agency “Condominium Sumairu Loan” (Official)

Cases where fire insurance can be used and cases where it should not be used

Building conditions and repair points in Izumi Ward, Yokohama City

Izumi Ward, Yokohama City, was established in November 1986 (Showa 61) when it was separated from Totsuka Ward. Throughout the history of the ward, the opening of the Sotetsu Izumino Line (from Futamatagawa Station to Izumino Station) in 1976, the extension to Izumi Chuo Station in 1990, the extension to Shonandai Station in 2000, and the commencement of the land readjustment project in the Izumi Yumegaoka area in 2015 have led to gradual development. As a result, the characteristic feature is that apartment buildings constructed in line with the growth of the ward are mixed with varying years of construction. Buildings constructed in the same period will reach their repair period at the same time.

Source: Yokohama City Izumi Ward “Ward Statistics Handbook” (PDF) / Yokohama City “Data on Greenery” (FY 2019)

Apartment buildings in Izumi Ward are divided into “four generations”

The apartment buildings in Izumi Ward reflect the history of the ward’s development in their varying years of construction. The type of heavy construction required for the next large-scale renovation will change depending on which generation your building belongs to.

Source: Yokohama City Izumi Ward “District Overview” (Based on the establishment of the district, the opening and extension of the Izumino Line, and the land readjustment project in the Izumi Yumegaoka area)

Four Unique Factors in Izumi Ward That Damage Buildings

We have organized four characteristics of Izumi Ward visible from public documents of Yokohama City that are linked to major repairs.

Source: Yokohama City Izumi Ward “Ward Overview” (PDF) / Yokohama City “Izumi Ward Urban Development (Revised Draft)” (PDF) / Yokohama City “Data on Greenery” / Yokohama City “Building Agreement (Izumi Ward)”・“District Planning” / Ministry of Land, Infrastructure, Transport and Tourism “FY2023 Comprehensive Survey on Condominiums” (PDF)

Key Issues to Address in Construction in Izumi Ward

*Kakeru Koumuten has five bases in Yokohama City and serves all areas of Izumi Ward, including Yayoi-dai, Ryokuen, Izumi Chuo, Izumi-cho, Nakada, Kamiida, and Okazu.

Deterioration Symptoms and Timing Requiring Major Repairs

Generally, major repairs are typically expected every 12 to 15 years. According to a survey by the Ministry of Land, Infrastructure, Transport and Tourism, the actual repair cycle is most commonly 13 years, with about 70% falling within the 12 to 15 year range, and the cycle tends to shorten with repeated occurrences. However, the actual judgment should be based on the condition of deterioration rather than just the number of years, so if you observe symptoms like those listed below, we recommend an early on-site inspection.

Repair Cycle Guidelines by Location (Ministry of Land, Infrastructure, Transport and Tourism Guidelines)

*The above are reference examples from the guidelines and are not uniform construction deadlines. Actual cycles will be set according to the specifications, location conditions, and deterioration status of the building.

Source: Ministry of Land, Infrastructure, Transport and Tourism “Guidelines for Creating Long-Term Repair Plans” (Revised June 2024, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “Survey on Large-Scale Repair Work for Condominiums in FY2021”

Examples of Large-Scale Renovation Work

This is an example of exterior renovation work on a mixed-use building handled by Kakeru Koumuten. The building had leaks occurring in several places, and we combined clear waterproofing for the tile exterior wall with waterproofing for the rooftop for the renovation.

Exterior Renovation Work on a Mixed-Use Building (Tile Exterior Wall Waterproofing + Rooftop Waterproofing)

Customer Feedback

Flow from On-Site Investigation to Completion of Construction

From inquiry to completion of construction and aftercare, one representative will consistently handle your case. In the case of management associations, a resolution at the general meeting is required, so starting the process 1 to 1.5 years before the desired start date will allow for a smoother progression.

1. Contact Us (Free) Please reach out via phone, form, or LINE. If you have estimates from other companies, it’s fine to just present those.
2. On-site Investigation & Building Diagnosis (Free) We will conduct a survey of the exterior walls, check for cracks, sealing, and waterproofing layers, and if necessary, use drones or thermal imaging to investigate the roof, high places, and leak areas. For properties in Izumi Ward, we will also check the condition of trees, delivery routes, parking, and the distance to neighboring properties.
3. Submission of Investigation Report & Estimate We will provide a deterioration diagnosis report with photos and an estimate detailing quantities, methods, and materials for each work item. Multiple plan proposals are also possible.
4. Plan Decision & Contract Confirm colors through color simulations, sample boards, and trial painting. For management associations, we can assist in preparing materials for general meetings. In areas subject to district planning or building agreements, we will also explain the considerations for color choices.
5. Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors to greet them, and set up a bulletin board at the entrance (with a schedule and laundry information). If temporary relocation of parking is necessary, we will coordinate this at this stage.
6. Installation of Temporary Scaffolding & Various Works Our own scaffolding team will set up the scaffolding, followed by high-pressure washing → substrate repair → sealing → exterior wall painting & tile repair → waterproofing → iron parts & ancillary work in that order. A supervisor will inspect each process and take construction photos.
7. Completion Inspection, Scaffolding Dismantling & Handover We will confirm the finish in the presence of the customer and provide construction photos, a report on the paint used, and a warranty certificate.
8. Aftercare Maintenance We will send out annual DM notifications, and inspections can be conducted every year. Simple repairs such as partial sealing are provided free of charge.

Resident Communication, Approval for Additional Work, Inspection Reports

Just as important as the construction itself is “when, what, and with what materials we report”. At Kakeru Koumuten, we will provide materials and reports in the following four situations.

* For management associations, it is smooth to decide in advance who will approve additional work (such as the chairman or repair committee) and the estimated amount that will require approval before the contract.

How Will Life Be During Construction? Impact on Residents

For large-scale repairs, the principle is to proceed while you continue to live in your home. However, there will be some limitations on your daily life while scaffolding is in place. Most troubles can be prevented by providing prior notice, so Kakeru Koumuten Co., Ltd. thoroughly explains and posts information before construction begins.

How to Choose a Large-Scale Repair Contractor and Ordering Method

There are many large-scale repair contractors that cover Izumi Ward in Yokohama City, and you may be unsure which contractor to choose. When requesting renovations for apartments, condominiums, or buildings, please check the following four points.

Have extensive experience in large-scale repairs

Large-scale repair contractors often have websites that showcase their exterior renovation achievements. If they provide detailed explanations of repair contents with photos, it gives you peace of mind as a reference when you actually request work.

Using Google and review sites to evaluate large-scale repair contractors can also be effective when comparing them! Be cautious if there are many negative reviews. If there are few reviews, also check their construction achievements, explanation content, and management system.

Large-scale repair work involves not only the construction itself but also the potential for conflicts with residents and neighbors. Therefore, it is necessary to post updates on the progress of the work and information about laundry on bulletin boards to prevent troubles before they occur. Kakeru Koumuten Co., Ltd. specializes in exterior work, and we receive many requests for exterior renovations of apartments and condominiums.

Check for Warranty and Aftercare Services

When choosing a large-scale repair company, let’s confirm the presence of a warranty. If any issues such as leaks occur after the construction, having a leak warranty from the contractor ensures that repairs can be made free of charge, providing peace of mind! Companies that offer a warranty period are often confident in their work, which can serve as a criterion for selecting a contractor.

The warranty period varies by contractor and the nature of the work, but it is generally set between 1 to 10 years. Emergency repairs or partial fixes often do not come with a leak warranty. Some contractors also offer aftercare services separate from the warranty, so be sure to check for the presence of warranties and aftercare services.

At Kakeru Koumuten Co., Ltd., we send out annual direct mail for aftercare maintenance, allowing for yearly inspections. We also provide free support for simple repairs such as partial sealing.

Obtain Estimates from Multiple Contractors (at least 3 companies)

When requesting large-scale repairs, be sure to obtain estimates from multiple contractors. It is important to get estimates from at least three companies and compare their estimates and reports! Even for the same work, costs can vary by contractor, and warranties and aftercare services may differ. Additionally, obtaining multiple estimates makes price negotiations easier.

When comparing estimates, consider not only the cost but also the “items in the estimate,” “methods and materials for substrate repair and exterior wall painting,” and “confirmation of the process” in detail! Costs can be lowered by using lower-grade materials or skipping steps, so avoid making decisions based solely on price. Especially since substrate repair work can be difficult to assess from appearance alone, be sure to check whether the repair method is appropriate for the condition of the substrate!

Check These Points on the Estimate (Checklist)

Confirm if it is managed in-house

Large-scale repair work includes various tasks such as “substrate repair work,” “exterior wall painting,” “waterproofing work,” and “pipe replacement,” and the plan content will change depending on the actual deterioration condition and customer preferences.

Contractors that completely outsource to subcontractors may lack knowledge and experience, leading to proposals for repairs in irrelevant areas or meaningless work. If you investigate and then request a subcontractor, it may incur additional time and costs. By having knowledge and experience and managing in-house, responsible construction at a reduced cost becomes possible.

Additionally, contractors that outsource may respond slowly in the event of trouble during construction. It is prudent to avoid having a company that has not actually met with the customer manage the construction. Kakeru Koumuten performs everything from temporary scaffolding installation to exterior wall painting and waterproofing work in-house, managed by knowledgeable and experienced personnel!

There are three ordering methods. The choice affects the approach.

Especially for management associations, it is necessary to decide “how to request” before “which company to hire.” The main ordering methods are the following three.

Collusion and Inappropriate Consulting Issues in Large-Scale Renovations and Self-Defense Measures

Latest 2026 In the large-scale renovation industry, inappropriate orders linked between design consultants and construction companies have long been a problem. The Ministry of Land, Infrastructure, Transport and Tourism issued warnings and notifications to management associations in January 2017 and April 2023, and on September 28, 2026, the Japan Fair Trade Commission announced that it had issued exclusion orders to 38 companies and a total of 1.63788 billion yen in payment orders to 37 companies regarding large-scale renovation work commissioned by condominium management associations to design consulting firms in the Kanto region (two design consulting firms were also subject to exclusion orders).

※Based on the Japan Fair Trade Commission announcement (September 28, 2026).

Three Typical Methods

Source: Yokohama City “What is collusion in large-scale repair work for condominiums?” / Ministry of Land, Infrastructure, Transport and Tourism “On the Proper Ordering of Large-Scale Repair Work for Condominiums” (Notification dated April 3, Reiwa 5, PDF)

Self-Defense Measures for Management Associations

• Obtain independent estimates from multiple companies
• Consult with neutral third parties such as condominium management professionals or architects
• Document the vendor selection process in minutes to ensure transparency
• Confirm the reasons for unusually low consulting fees
• Include a penalty clause in the contract for cases of collusion
• Avoid concentrating information with a single consultant and verify specifications independently

New System in Yokohama City Bid Agency Service for Large-Scale Repair Work

In response to this issue, in October 2025, Yokohama City and the Yokohama Housing Supply Corporation established the “Bid Agency Service for Large-Scale Repair Work.” This system separates the selection of design and construction companies, with the corporation acting as a third party to conduct conditional general competitive bidding. The estimated price will not be disclosed, and the process will follow methods similar to public works.

Source: Yokohama City Press Release (October 16, 2025) / Yokohama Housing Supply Corporation

Frequently Asked Questions about Large-Scale Repairs in Izumi Ward, Yokohama

How much does large-scale repair in Izumi Ward, Yokohama cost?

For apartments, according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for the fiscal year 2021, about 70% fall within the range of 750,000 to 1,500,000 yen (excluding consumption tax and common temporary construction costs), with the most common being 1,000,000 to 1,250,000 yen. Yokohama City also indicates “approximately 1,000,000 to 1,300,000 yen per unit.” Based on our company’s track record, the cost for a two-story wooden apartment ranges from 2,000,000 to 4,000,000 yen, for a three-story steel or RC apartment from 4,000,000 to 9,000,000 yen, and for small-scale apartments or mixed-use buildings from 5,000,000 to 15,000,000 yen. The cost varies depending on the condition of the substrate and whether waterproofing or roofing work is needed, so we provide free on-site estimates.

How often should large-scale repairs be conducted?

Generally, a cycle of 12 to 15 years is recommended, and the actual cycle is most commonly 13 years according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey, with about 70% falling within 12 to 15 years. However, the decision should be based on the condition of deterioration rather than just the number of years. If signs of deterioration such as sealing degradation, tile lifting, or waterproof layer rupture are observed, it is advisable to conduct repairs without waiting for the cycle, as this can ultimately reduce costs. Older buildings tend to have a greater proportion of tile repairs and metal part replacements during the second and third repairs.

How long does the construction period take? Can residents stay during the work?

For apartments, the duration is typically 3 weeks to 2 months, for small-scale apartments or buildings 1.5 to 3 months, and for apartments with over 50 units about 4 to 6 months. Residents can remain in their homes during the construction. However, there will be restrictions on drying laundry outside and opening windows while scaffolding is in place, so we take thorough measures to minimize the impact on daily life, including distributing advance notices, providing information on the schedule and laundry through bulletin boards, and strictly adhering to working hours.

How long should I expect from the start of planning to the completion of construction?

For management associations, it typically takes about 1 to 1.5 years for the establishment of the repair committee, building diagnosis, contractor selection, and general meeting resolutions, followed by 3 to 6 months for the construction itself. Overall, it is advisable to plan for around 2 years to proceed comfortably. If utilizing subsidies or tax incentives, please also factor in the time required to obtain management plan certification (2 to 3 months from application to certification).

Are there any subsidies available for large-scale repairs in Izumi Ward, Yokohama?

Neither Yokohama City nor Kanagawa Prefecture offers subsidies specifically for large-scale repair work. However, for condominium apartments, if certain conditions are met, there are reductions in fixed property tax by half under the “Condominium Longevity Promotion Tax System,” subsidies from Yokohama City for deterioration diagnosis and long-term repair planning (half, up to 200,000 yen), and subsidies for barrier-free renovations in common areas (one-third, up to 300,000 yen). If the work includes windows and insulation, it may qualify for “Advanced Window Renovation 2026” or “Mirai Eco Housing 2026.” The application timing and applicants vary by system, so please check the eligibility conditions and application procedures for each system before contracting or starting construction.

I heard that fixed property taxes can be reduced through large-scale repairs. Is that true?

It is true if the conditions are met. Under the Condominium Longevity Promotion Tax System, if a condominium apartment that meets the requirements, such as being over 20 years old and having more than 10 units, conducts large-scale repairs that contribute to longevity (including exterior painting, floor waterproofing, and roof waterproofing), the fixed property tax for the following year will be reduced by half for up to 100 square meters per unit. This applies to work completed between April 1, 2023, and March 31, 2027, and a declaration must be made to the Izumi Ward Office within three months of completion. For management plan certified condominiums, there are additional requirements such as raising the repair reserve fund, which takes time to prepare, so it is recommended to start the process more than a year in advance.

Are there any changes to subsidies starting from the fiscal year 2026?

Yes. The national “Child-Rearing Green Housing Support Project” has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Management associations and management association corporations can also become joint project participants, allowing for insulation renovations in common areas. Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in fiscal year 2025 and will not be implemented in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has begun accepting bulk applications for apartment buildings starting May 29, 2026 (application procedures are handled by registered contractors). Please be careful not to base your financial planning on outdated information.

What should I do if the repair reserve fund is insufficient?

The options are mainly four: ① Postpone low-urgency work after a deterioration diagnosis to the next time, ② Review the scope and specifications of the work, ③ Check support systems such as subsidies, ④ Consider increasing the repair reserve fund or loans from the Japan Housing Finance Agency. The agency’s condominium common area renovation loan does not require collateral, and the interest rate can be reduced by up to 0.6% per year by obtaining management plan certification and implementing energy-saving and seismic work. Please note that postponing waterproofing and tile peeling measures often ends up being more expensive, so please consult us for a decision on separation.

Can you handle large-scale repairs for properties with many buildings, like in a housing complex?

You can consult us. For properties with many buildings, it is important to conduct deterioration diagnoses for each building, plan the process for whether to do them all together or separate by building or year, and form consensus at the general meeting. Kakeru Koumuten Co., Ltd. also targets condominiums with over 100 units as a cost estimate and will propose multiple process plans for comparison.

What happens to the residents’ parking during construction?

Vehicles on the side where scaffolding is set up will need to be temporarily moved. In buildings with limited parking availability, it may take time to secure an alternative location. Kakeru Koumuten Co., Ltd. will coordinate with you about the availability of nearby coin parking and monthly parking lots starting 2 to 3 months before construction begins.

Can I freely decide the color of the exterior walls?

In Izumi Ward, there are two building agreements (Nishigaoka District and Okazu District) listed by Yokohama City, and district plans are established for areas such as Izumi Yayoi-dai Housing Area, Izumi Ryokuen 1st and 2nd Chome Areas, and Izumino Station North Exit Area. The existence and content of agreements and plans regarding appearance and color vary by agreement and plan, so it is important to check in advance. You can confirm what applies to your property through Yokohama City’s public information on building agreements and district plans, and the Izumi Ward Office’s Urban Development Promotion Division (045-800-2331) also provides guidance on urban development in the ward. We will also investigate this during our research. Sharing a color simulation to visualize the completed image can facilitate discussions with neighbors and the neighborhood association.

Why is the north-facing exterior wall particularly covered in moss and algae?

Izumi Ward has a green coverage rate of 36.3% (as of the 2019 survey; city average 27.8%), making it a green area where shaded surfaces from trees are common. When sunlight is insufficient and humidity is high, moss, algae, and mold can thrive. By thoroughly cleaning with high-pressure washing and choosing paint with anti-algae and anti-mold properties, recurrence can be minimized. Additionally, we recommend checking for blockages in roof drains and gutters caused by fallen leaves, as these often lead to puddles on the roof and leaks.

Which should I choose, the responsibility construction method or the design supervision method?

For properties with fewer units, the burden of consulting fees tends to be heavier, so we believe that the responsibility construction method is often more suitable for small to medium-sized buildings. The design supervision method allows for comparison of construction companies under the same conditions since a third party creates the specifications; however, it incurs separate consulting fees and requires caution regarding conflicts of interest and collusion risks. Even with the responsibility construction method, verifying price, specifications, and construction status is essential. Kakeru Koumuten Co., Ltd. provides detailed estimates listing quantities, methods, and materials for each construction item, allowing for comparison on the same level as other companies.

How can I detect collusion in large-scale repairs?

There are three typical tactics. ① Pre-selecting a contractor and having other companies submit only nominally high estimates, known as “dummy estimates,” ② A consultant signing a contract with an extremely low design supervision fee and receiving kickbacks from partner companies, ③ Adding a portion of the contract amount as a back margin to the construction costs. Countermeasures include obtaining independent estimates, consulting a neutral third party, documenting the selection process in meeting minutes, and including penalty clauses in contracts. In October 2025, Yokohama City and the Yokohama City Housing Supply Corporation will establish a “Large-Scale Repair Work Bidding Agency Service.”

How many companies should I get estimates from?

We recommend at least three companies. If there are too many, comparisons become unmanageable; if too few, competition does not occur. What is important is not the number of companies but “creating the same playing field before comparing.” By creating a common specification sheet and quantity table and requesting estimates under the same conditions, and by requiring detailed breakdowns instead of accepting “one set” notation, it becomes clear whether price differences are due to variations in scope or unit prices.

What is the difference if you own your own scaffolding?

Among the costs of large-scale repair work, temporary construction accounts for about 20% (according to the Ministry of Land, Infrastructure, Transport and Tourism’s fiscal year 2021 survey). By not outsourcing scaffold work, we can easily control costs in this area, and our in-house scaffold team can flexibly respond to sudden changes in the schedule or additional work. Kakeru Koumuten Co., Ltd. owns scaffold materials for approximately 100 single-family homes and plans the scaffolding on-site according to the site conditions.

Can I just have a look at the estimate while I’m comparing quotes?

Of course, that’s possible. If you bring in estimates from other companies, we will check for free whether the items, quantities, methods, and materials are appropriate, and provide you with an estimate under the same conditions. We welcome competitive estimates.

Can I request just an emergency repair for a leak?

Yes. As a preliminary step before large-scale repairs, we also accept requests for emergency repairs or partial repairs for leaks. We will identify the cause using thermography and drones and propose the minimum necessary repairs.

Can you handle roofing or exterior wall materials that contain asbestos?

Yes, we can. We have qualified personnel such as asbestos work supervisors and building material asbestos surveyors, and we handle everything from the legally required preliminary surveys to the cover method and removal of asbestos-containing roofing materials. If there is sprayed asbestos, you may be eligible for free surveys and subsidies covering two-thirds of the removal costs (up to 3 million yen) through Yokohama City’s countermeasures project, so we will provide that information as well.

What happens if we don’t do large-scale repairs?

There are risks such as personal injury accidents due to falling exterior wall tiles, structural deterioration due to corrosion of rebar, leaks, and a decrease in asset value. Furthermore, for buildings subject to periodic reporting under Article 12 of the Building Standards Act, investigations through full tapping and other methods are required under certain conditions, such as when more than 10 years have passed since completion or exterior wall renovations for tiled or mortar-finished walls. In Yokohama City, buildings that are only apartment complexes are not designated for periodic reporting, but mixed-use buildings that include stores require individual confirmation. Even if not subject to statutory inspections, regular inspections and maintenance are essential, so please consult us if you are unsure.

How much does large-scale repair for an apartment (about 10 units) cost?

For a wooden two-story building with 6 to 10 units, the estimate is around 2 million to 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it is about 4 million to 9 million yen based on our company’s track record (including scaffolding, substrate repairs, exterior wall painting, sealing, and waterproofing). It is common for apartments to undergo repairs every 10 to 15 years. For owners, there is an increasing trend to change the appearance with color simulations during repairs to improve occupancy rates.

If you are looking for a large-scale repair contractor in Izumi Ward, Yokohama City, contact Kakeru Koumuten

Our company is based in Yokohama City and has handled many exterior wall renovations and large-scale repairs for condominiums and apartments in Izumi Ward. We are happy to assist not only with large-scale repair work but also with partial repairs and leak repairs. In urgent cases like leaks, emergency repairs may be possible, so please feel free to consult us. “I want it to last long with one renovation” “I want to keep costs down as much as possible” “I want to improve insulation performance because the interior is hot” We will propose optimal solutions for your specific requests and future repair plans.

From temporary scaffolding work to roofing and exterior wall painting, all work is performed by our own team. We are confident that we will not be outdone by others in terms of cost, quality, and planning, so we welcome competitive estimates!

Areas Covered for Large-Scale Repair Work

Kakeru Koumuten Co., Ltd. accepts requests for work throughout Kanagawa Prefecture and Tokyo.

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