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

Large-Scale Repairs for Condominiums, Apartments, and Buildings in Asahi Ward, Yokohama

Large-scale repair work we can handle in Asahi Ward, Yokohama

Large-scale repairs are not just “exterior wall painting” or “waterproofing,” but rather a comprehensive repair of the entire building’s deterioration while scaffolding is in place. At Kakeru Koumuten, we can handle all the work listed below with our own team, ensuring clear responsibility and coordination of the process.

Scope of Major Repairs Determined from Building Diagnosis

It is not always necessary to carry out all of 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 free on-site surveys to confirm the following and compile a deterioration diagnosis report with photos, after which we will propose the scope of work.

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

The reason why we can be entrusted with large-scale repairs in Asahi 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 for 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, metals, and wood are generated. At Kakeru Koumuten, we separate and recycle waste materials in-house, which helps reduce waste disposal costs.

Exterior Renovation Dedicated Showroom

In the showroom, you can not only have meetings but also check actual samples and colors of exterior materials. You can also perform color simulations for exterior wall painting and check thermal insulation properties using a thermal insulation testing machine!

2. Cost Reduction through In-House Management and Construction

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

By managing everything from inquiries to project completion in a unified system by Kakeru Koumuten, we can keep costs down while providing high-quality large-scale repairs. Additionally, one representative will handle everything from the estimate to project completion. Since the person in charge does not change, whether it’s sales or construction management, smooth communication is possible.

We can fully handle everything from temporary scaffolding installation to exterior wall painting, substrate repairs, waterproofing work, and tile repairs with our own team! 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 national 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 building material asbestos surveyors, so we can handle asbestos-containing roofing materials and conduct preliminary surveys.

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 every year, and we send out notification DM each 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 drones! During leak investigations, we can use a thermal imaging camera to help identify the cause of leaks!

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

6. Staff Development

Our staff create various models for skill improvement 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 important points and inspection areas to be aware of during each stage of large-scale repair work.

7. Consideration for Residents and Neighbors

During large-scale repair work, we will not only notify residents and greet nearby residents, but we will 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 stage of the process will be inspected by a responsible person, and detailed construction photos will be taken. We use film thickness inspection devices and checklists to ensure that no inspections are missed. During exterior wall painting and waterproofing work, we will confirm the number of used paint cans to ensure that the specified amount of paint is used, and we will 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

Our simulations can be created from actual photos of your apartment or building!Simulations can also be done on your smartphone or computer. By simulating and then changing to a two-tone color or making an image change, we hope to enhance the stylish appearance and increase occupancy rates! Of course, we can also arrange paint samples for actual color confirmation.

* In Asahi Ward, there are areas 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 can help facilitate explanations at community meetings and general meetings.

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

You can order samples of the paint you are considering and conduct a sample paint application on your exterior wall. By doing a sample 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 minimize the risk of failure in changing the image! We hope that renovating the appearance of your apartment or condominium will help increase occupancy rates.

Cost Estimate for Major Repairs in Asahi Ward, Yokohama City

The cost of major repairs varies significantly 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 unit price examples 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 compiled 818 construction cases (FY 2021), approximately 70% of the costs for major repairs are concentrated 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 the conditions differ from the current total construction cost including tax.

Source: Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Renovation Costs for Condominiums” (200 companies, 818 cases) / Yokohama City “Market Prices for Large-Scale Renovation Costs and How to Address Shortfalls in Repair Reserves” *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 “Fiscal Year 2021 Survey on Large-Scale Renovation Costs for Condominiums” (Second survey of large-scale renovation costs. Overall average is construction-related 59.0%, temporary construction 22.3%, miscellaneous expenses 9.9%). *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 assessing the appropriateness of individual estimates.

Cost Estimates by Building Size (Scaffolding, Substrate Repair, Exterior Painting, Waterproofing, and 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 amount calculated by multiplying the national statistics (750,000 – 1,500,000 JPY per unit) by the number of units.

Breakdown of Costs for Temporary Works, Substrate Repair, Exterior Walls, and Waterproofing

The estimate for large-scale repairs is broadly divided into “Temporary Works,” “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 based 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 of charge.

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 the next major repair will be with the lifespan of the materials to avoid unnecessary waste.

* The estimated lifespan is a general guideline and may vary depending on sunlight, location, and substrate condition. In areas like Asahi 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

According to the Ministry of Land, Infrastructure, Transport and Tourism guidelines, the guideline for repair reserve funds is indicated as a monthly amount per exclusive area. Additional charges are necessary 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 there is a shortfall.

Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Asahi 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 the following four types. The eligibility and application status of the systems may change even during the fiscal year, so 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 (Property Tax Reduction)

If large-scale repairs (all three types: exterior painting, floor waterproofing, and roof waterproofing) that contribute to the longevity of condominiums meeting certain requirements are carried out, the 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 Condominium Management in Yokohama City (Management Associations Start Here)

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

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

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

This is a system certified by Yokohama City, and upon certification, the loan interest rate from the Japan Housing Finance Agency is reduced by 0.2% per year, preferential interest rates for Flat 35, and it 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, establishing management regulations, separate accounting for management fees and repair reserves, overdue amounts within 10% of the total, and “having created or reviewed a long-term repair plan that includes large-scale repair work twice or more within 30 years and within 7 years.”

*Fees include a system usage fee of 10,000 yen + city application fee of 3,900 yen, among others. It takes 2 to 3 months from application to certification. The certification is valid for 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 Excellent 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 (Application for the 2026 fiscal year has 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)

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

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 Asahi Ward, Yokohama City

Asahi Ward, Yokohama City, was established in October 1969 (Showa 44). The population, which was about 140,000 at the time of the ward’s establishment, has now increased to about 240,000. From the areas around Futamatagawa Station and Tsurugamine Station to housing complexes and single-family residential areas, the mixed layers of collective housing built along with the growth of the ward are a characteristic feature. Buildings constructed during the same period will reach their repair period at the same time.

Source: Yokohama City Asahi Ward “Data on Asahi Ward” (PDF) / Yokohama City “Data on Greenery” (Reiwa 1)

Collective Housing in Asahi Ward is Divided into “Four Generations”

The collective housing in Asahi Ward reflects the history of housing complex development, forming layers of construction years. The type of heavy work required for the next large-scale renovation will vary depending on which layer your building falls into.

Source: Yokohama City Asahi Ward “Data on Asahi Ward” (Construction periods of housing as of October 1, Reiwa 5) / Yokohama City “Asahi Ward Housing Complex Regeneration” related documents (Housing Complex Regeneration Vision, Wakaba-dai Housing Complex)

Four Factors Unique to Asahi Ward That Damage Buildings

We have organized four characteristics of Asahi Ward visible from Yokohama City’s public documents that are linked to large-scale repairs.

Source: Yokohama City “Katabiragawa”／Yokohama City “River Maintenance” (PDF)／Yokohama City “Data on Greenery”／Yokohama City “Building Agreement (Asahi Ward)”・“District Planning”／Ministry of Land, Infrastructure, Transport and Tourism “FY2023 Comprehensive Survey on Condominiums” (PDF)

Key Issues to Address in Asahi Ward During Construction

* Kakeru Koumuten has five bases in Yokohama City and serves all areas of Asahi Ward, including Futamatagawa, Tsurugamine, Wakabadai, Sakonyama, Kibogaoka, Imajuku, and Shirane.

Signs of Deterioration Requiring Major Repairs and Timing

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 each occurrence. However, the actual decision should be based on the condition of deterioration rather than the number of years, so if you observe symptoms like those listed below, we recommend an early on-site inspection.

Repair Cycle Guidelines by Part (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 “Long-term Repair Plan Creation Guidelines” (Revised June 2024, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Repair Work for Condominiums”

Examples of Large-Scale Renovation Work

This is an example of exterior renovation work on a mixed-use building undertaken 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 roof for the renovation.

Exterior Renovation Work on a Mixed-Use Building (Tile Exterior Wall Waterproofing + Roof 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 necessary, so it is advisable to start moving 1 to 1.5 years before the desired start date to proceed with ample time.

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 Asahi Ward, we will also check the condition of trees, delivery routes, parking, and the distance to neighboring properties.
3. Investigation Report & Estimate Submission 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 using color simulations, paint samples, and trial painting. For management associations, we can assist in preparing materials for general meetings. In areas subject to district planning and building agreements, we will also explain the considerations for color choices.
5. Notification to Residents & Neighbors We will distribute construction notifications, conduct greetings to neighbors, 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. Temporary Scaffolding Installation & 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 responsible person will inspect and take construction photos at each stage.
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.
8. Aftercare Maintenance We will send annual DM notifications and inspections can be conducted every year. Simple repairs such as partial sealing are provided free of charge.

Resident Communication, Additional Work Approval, 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 approximate 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 living in your home. However, there will be some limitations on daily life while scaffolding is in place. Most troubles can be prevented by notifying in advance, so Kakeru Koumuten Co., Ltd. thoroughly provides explanations and notices before construction.

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

There are many large-scale repair contractors that cover Asahi 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 troubles with residents and nearby neighbors. Therefore, it is necessary to post updates on the progress of the work and information about laundry on bulletin boards to prevent issues before they arise. 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, make sure to check for warranties. If any issues such as leaks occur after the work is completed, having a leak warranty from the contractor ensures that repairs can be made at no cost, providing peace of mind! A company that offers a warranty is often confident in its work, making it a key criterion for selecting a contractor.

Warranty periods vary by contractor and the nature of the work, but typically range from 1 to 10 years. Emergency repairs or partial fixes often do not come with a leak warranty. Some contractors also provide aftercare services separate from warranties, so be sure to check for 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 assistance 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 3 companies and compare their quotes and reports! Even for the same work, costs can vary between contractors, 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 repairs and exterior painting,” and “confirmation of the process” to make an informed decision! If the quality of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price. Especially since substrate repair work can be hard to assess from appearance alone, ensure that the repair method is suitable for the condition of the substrate!

Check These Points on the Estimate (Checklist)

Confirm whether 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 based 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 that keeps costs down becomes possible.

Moreover, contractors that outsource may also face delays in responding if any troubles occur during construction. It is safer to avoid companies that do not have direct meetings with customers managing the construction. Kakeru Koumuten performs everything from temporary scaffolding setup 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 38 companies received exclusion orders regarding large-scale renovation work commissioned by condominium management associations to design consulting firms, and 37 companies were ordered to pay a total of 1.63788 billion yen in surcharges (two design consulting firms were also subject to exclusion orders).

※This content is based on the announcement by the Japan Fair Trade Commission (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 specialists or architects
• Document the contractor selection process in meeting 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 by the management association itself

New System in Yokohama City Bidding 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 “Bidding 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 public 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 Asahi Ward, Yokohama City

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

For condominiums, according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for the fiscal year 2021, about 70% falls within the range of 750,000 to 1,500,000 yen (excluding consumption tax and common temporary construction costs), with the most common range 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 construction records, the cost for a two-story wooden apartment is estimated at 2,000,000 to 4,000,000 yen, for a three-story steel or RC apartment at 4,000,000 to 9,000,000 yen, and for small condominiums or mixed-use buildings at 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 required, 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 determining factor is not the number of years but the condition of deterioration. If deterioration of sealing, tile lifting, or breaks in the waterproof layer are observed, it is advisable to repair 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 in the second and third repairs.

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

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

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

For management associations, it typically takes about 1 to 1.5 years for establishing a repair committee, conducting building diagnostics, selecting contractors, and passing resolutions at general meetings, followed by 3 to 6 months for construction. Overall, it is advisable to plan for about 2 years to proceed comfortably. If using subsidies or tax incentives, please also factor in the time to obtain management plan certification (2 to 3 months from application to certification).

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

Both Yokohama City and Kanagawa Prefecture do not provide subsidies specifically for large-scale repair work. However, for condominium owners, 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 making common areas barrier-free (one-third, up to 300,000 yen). If the work includes windows and insulation, it may qualify for “Advanced Window Renovation 2026” or “Future Eco Housing 2026.” The timing and applicants for each system vary, so please check the eligibility conditions and application procedures for each system before contracting or starting construction.

I heard that fixed property tax can be reduced with large-scale repairs; is that true?

Yes, it is true if certain conditions are met. Under the Condominium Longevity Promotion Tax System, if a condominium 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 can 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 Asahi Ward Office within three months of completion. For certified management plan condominiums, there are additional requirements such as increasing the repair reserve fund, which takes time to prepare, so we recommend starting the process more than a year before construction.

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

Yes, there are. The national “Child-Rearing Green Housing Support Project” has been abolished and reorganized into the successor “Future Eco Housing 2026 Project.” Management associations and management 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 there will be no implementation in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has begun accepting bulk applications for apartment buildings starting May 29, 2026 (the application process is 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 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 repair reserve funds or loans from the Japan Housing Finance Agency. The Agency’s condominium common area renovation loan does not require collateral, and by obtaining management plan certification and implementing energy-saving and seismic work, the interest rate can be reduced by up to 0.6% per year. 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. In Asahi Ward, there are large-scale housing complexes over 35 years old, such as Wakabadai and Sakonyama, highlighted in Yokohama City’s documents. For properties with many buildings, it is important to conduct deterioration diagnosis for each building, create a process plan for whether to do it all together or separate by building or year, and form consensus at the general meeting. Kakeru Koumuten Co., Ltd. also targets cost estimates for condominiums with over 100 units and will propose multiple process plans for comparison.

What happens to residents’ parking during construction?

Vehicles on the side where scaffolding is erected will need to be temporarily moved. Asahi Ward has 74,173 registered passenger vehicles (as of March 31, Reiwa 7), and in buildings with limited parking availability, it may take time to secure a relocation spot. Kakeru Koumuten Co., Ltd. will coordinate with you about the availability of nearby coin parking and monthly parking starting 2 to 3 months before construction begins.

Can I freely decide the color of the exterior walls?

Asahi Ward has 10 building agreements, and there are district plans established around locations like Futamatagawa Station. The existence and content of agreements regarding appearance and color vary by agreement and plan, so prior confirmation is essential. You can inquire about what applies to your property at the Asahi Ward Office, District Administration Promotion Division (045-954-6026). We will also investigate during our assessment. Sharing a color simulation to visualize the completed image can facilitate discussions with neighbors and the community association.

Why is the north-facing exterior wall so badly affected by moss and algae?

Asahi Ward has a green coverage rate of 33.9% (as of the 2019 survey, ranked 2nd among 18 wards), making it a green area where surfaces can easily be shaded by trees. When sunlight is insufficient and humidity is high, algae, moss, and mold can thrive. By thoroughly removing them with high-pressure washing and choosing paint with anti-algae and anti-mold properties, you can suppress recurrence. 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 method should I choose, responsibility construction or design supervision?

In smaller buildings, the burden of consulting fees tends to be heavier, so we believe that the responsibility construction method is often more suitable for 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 estimates that clearly outline quantities, methods, and materials for each construction item, allowing you to compare on the same level as other companies.

How can I detect collusion in large-scale repairs?

There are three typical tactics. ① Pre-selecting the contractor and having other companies submit only nominally high estimates, known as “dummy estimates,” ② A consultant contracts at an extremely low design supervision fee and receives kickbacks from affiliated contractors, creating collusion, 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 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, it becomes difficult to compare; if too few, competition does not occur. What is important is not the number of companies but “creating the same level of comparison.” By creating a common specification sheet and quantity table and requesting under the same conditions, and requiring detailed breakdowns instead of a lump-sum notation, it becomes clear whether the price difference is due to differences in scope or unit price.

What is different about having scaffolding owned by the company?

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 keep costs down 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 scaffolding on-site according to the site conditions.

Can I just have a look at the estimate while I’m in the process of getting multiple 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 multiple quotes.

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 thermal imaging 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, including asbestos work supervisors and building material surveyors, who can handle everything from the legally mandated 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 information on that as well.

What happens if I don’t carry out large-scale repairs?

There are risks such as personal injury from falling exterior wall tiles, structural deterioration due to corrosion of rebar, leaks, and a decrease in asset value. Furthermore, for buildings subject to regular reporting under Article 12 of the Building Standards Act, investigations through full probing 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 apartments are not designated for regular reporting, but mixed-use buildings that include stores require individual confirmation. Even if not subject to statutory investigations, 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 two-story wooden building with 6 to 10 units, the estimate is 2 million to 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it is 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 using color simulations during repairs to improve occupancy rates.

If you are looking for a large-scale repair contractor in Asahi Ward, Yokohama City, contact Kakeru Koumuten Co., Ltd.

Our company is based in Yokohama City and has handled many exterior wall renovations and large-scale repairs for condominiums and apartments in Asahi Ward. We are happy to assist not only with large-scale repair work but also with partial repairs and leak repairs. In urgent cases such as leaks, emergency measures 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 indoors are hot” We will propose the best 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 multiple quotes!

Large-scale repair work service areas

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

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