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

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

Large-scale repair work that can be handled in Sakae 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 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 of the above works. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten, we conduct a free on-site survey 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 Sakae Ward, Yokohama

The reason why we can be entrusted with large-scale renovations in Sakae Ward is partly because “Kakeru Koumuten has a base in Yokohama City”, but also because of our “initiatives in large-scale renovation work that cannot be imitated by other companies”, which have been well received by many customers.

1. Equipment Specialized for Exterior Renovation

At Kakeru Koumuten, we have prepared the following warehouses and material storage areas to provide low-cost and high-quality exterior wall painting and waterproofing work for large-scale renovations. 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 renovations and can assemble the scaffolding ourselves.
By not outsourcing scaffolding work and using our own scaffolding team, 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

In large-scale renovations, various waste materials such as waste paint, metal, and wood are generated. At Kakeru Koumuten, we separate and recycle waste materials in-house, which helps reduce waste disposal costs.

Showroom Dedicated to Exterior Renovation

In the showroom, you can not only have meetings but 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 sales or construction management, smooth communication is possible.

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

3. 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 projects for factories! We have qualified personnel for asbestos work supervisors and building materials containing asbestos inspectors, so we can manage asbestos-containing roofing materials and conduct preliminary investigations.

4. Warranty and Aftercare

Most large-scale repair works come with a warranty for services such as “painting work,” “substrate repair work,” and “waterproofing work”!
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 in 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 utilize 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 enhancement and conduct practical training. Since different sites require various processing and techniques, we regularly provide skill improvement education to ensure each staff member can respond effectively. We also educate on points to be cautious of and areas to check in 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 also install a notice board at the entrance to display the construction schedule and announcements! 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 will use film thickness inspection machines and check sheets to ensure that there are no oversights in the inspections. During exterior wall painting and waterproofing work, we will check the quantity of used paint cans to confirm that the specified amount of paint is being used, and by ordering paint in-house, we will prevent construction defects in advance. 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 created by our company can be done using actual photos of your apartment or building!You can also perform the simulation on your smartphone or computer. By simulating before making a two-tone color change or image change, we hope to enhance the stylish appearance and contribute to an increase in occupancy rates! Of course, we can also arrange paint samples for actual color confirmation.

* In Sakae 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 make explanations at neighborhood associations and general meetings proceed smoothly.

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

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

9-3 Exterior Renovation Simulation

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

With the exterior renovation simulation, you can minimize the risk of failure in your image change! We hope that renovating the appearance of your apartment or condominium will help increase occupancy rates.

Cost Estimates for Major Repairs in Yokohama City Sakae Ward

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 cost estimates based on our construction records, 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 compiled 818 construction cases (FY 2021), the construction costs for major repairs are concentrated at about 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 Shortages 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 “Survey on Large-Scale Renovation Work for Condominiums in FY2021” (Second aggregation of large-scale renovation work. Overall average is construction-related 59.0%, temporary work 22.3%, miscellaneous expenses 9.9%). *The total does not equal 100% because equipment-related work, exterior works, and others are included. This is an average value and not a criterion for judging the appropriateness of individual estimates.

Cost Estimates by Building Scale (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 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 Structures, Substrate Repair, Exterior Walls, and Waterproofing

The estimate for large-scale repairs is broadly divided into “Temporary Structures,” “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 to perform the next major repair with the lifespan of the materials, minimizing waste.

* The estimated lifespan is a general guideline and may vary depending on sunlight, location, and substrate condition. Since deterioration progresses differently for each side of a property with many slopes or varying sunlight and wind exposure, it is advisable to confirm the condition of each side through a site survey and select paint suitable for the location to improve 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 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 reported that “repair reserve funds are insufficient compared to the plan.” There are four main options when funds are insufficient.

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

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 these systems may change 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 8, 2026)

① Condominium Longevity Promotion Tax System (Property Tax Reduction)

If large-scale repairs (including 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 the equivalent of 100㎡ per unit; urban planning tax is not included).

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

② Support for Apartment Management in Yokohama City (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 (Tax and Interest Rate Benefits)

This is a system certified by Yokohama City. 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 Lifespan Promotion Tax System (certification alone does not guarantee tax reduction). The main criteria include holding general meetings at least once a year, maintaining management regulations, separate accounting for management fees and repair reserve funds, overdue amounts within 10% of the total, and “having a long-term repair plan that includes large-scale repair work twice or more over a period of 30 years or more, created or reviewed within 7 years”, among others.

*The fees are a system usage fee of 10,000 yen + the city’s 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 FY 2026The “Child-Rearing Green Housing Support Project” for FY 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 FY 2027 and will not be implemented in FY 2028. Please be careful not to establish financial plans based on outdated information.

Mirai Eco Housing 2026 Project

Advanced Window Renovation 2026 Project

⑤ Kanagawa Prefecture Subsidies (Applications for Fiscal Year 2026 have ended)

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

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 Sakae Ward, Yokohama City

Sakae Ward, Yokohama City, was established on November 3, 1986, through the reorganization of administrative districts, separating from Totsuka Ward. According to ward documents, it is characterized by the Itachigawa River flowing east-west through the center of the ward, and the Kashio River flowing north-south on the west side, forming lowlands surrounded by hilly areas connected to the Miura Peninsula. From the 1960s to the early 1970s, large-scale residential development centered around the hilly areas took place, leading to a rapid population increase and transformation into a residential city. It is also characterized by a small area of residential land and a large area of forest. Depending on the location, the way buildings deteriorate and the method of scaffolding also change.

Source: Yokohama City Sakae Ward “SAKAE Quick Reference Note (Sakae Ward Statistical Overview)” (Population, Households, Elderly Population)／Same (Location, Topography, Green Coverage Rate)／Yokohama City “Data on Greenery” (FY 2019)／Yokohama City “Building Agreement (Sakae Ward)”／Yokohama City Sakae Ward “History of Sakae Ward”

Buildings in Sakae Ward are divided into “four types”

Sakae Ward has different urban developments depending on the location, so not only the age of the building but also the location of the building (lowland urban area, hilly residential area, redeveloped area in front of the station, slopes near greenery) will affect the nature of the major repairs required in the next large-scale renovation. Please check which type your building falls under.

Source: Yokohama City Sakae Ward “History of Sakae Ward” / Same “Sakae Ward Statistical Overview (Location and Topography)” / Yokohama City “Oofuna Station North Second District” District Plan・“Hongodai Station Surrounding Area” District Plan

Four Factors Unique to Sakae Ward That Damage Buildings

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

Source: Yokohama City “Flood Hazard Map” / Yokohama City “Landslide Hazard Map” / Yokohama City “Data on Greenery” / Yokohama City “Architectural Agreements (Sakae Ward)”・“District Plans”・“Sakae Hongodai Area”／Ministry of Land, Infrastructure, Transport and Tourism “Reiwa 5 Fiscal Year Comprehensive Survey on Condominiums” (PDF)

Key Points to Consider When Proceeding with Construction in Sakae Ward

*Kakeru Koumuten has five bases in Yokohama City and serves the entire Sakae Ward, including Hongodai, Ofuna, Katsuradai, Kosugegaya, Kamigou, Kasama, and Nagao-dai.

Signs of Deterioration Requiring Major Repairs and Timing

Generally, major repairs are estimated to occur on a 12 to 15-year cycle. According to the Ministry of Land, Infrastructure, Transport and Tourism’s actual survey, 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 survey.

Estimated Repair Cycles 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 from several locations, and we renovated it by combining clear waterproofing for the tile exterior walls and waterproofing for the roof.

Exterior Renovation Work on a Mixed-Use Building (Tile Exterior 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 starting the process 1 to 1.5 years before the desired start date allows 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 Survey & Building Diagnosis (Free) We will conduct an exterior wall inspection, check for cracks, sealing, and waterproof layers, and if necessary, use drones or thermal imaging to investigate the roof, high places, and leak areas. For properties in Sakae Ward, we will also check the slope and elevation differences of the site, retaining walls, drainage, tree conditions, access routes, parking, and distances to neighboring properties.
3. Survey 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 plans can also be proposed.
4. Plan Decision & Contract Confirm colors through 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 or building agreements, we will also explain the considerations for color choices.
5. Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors for greetings, and set up a bulletin board at the entrance (with a schedule and laundry information). If temporary relocation of parking is necessary, adjustments will be made at this stage.
6. Temporary Scaffold Installation & Various Works Our in-house scaffold team will set up the scaffolding, followed by high-pressure washing, substrate repairs, sealing, exterior wall painting, tile repairs, waterproofing, and work on metal parts and accessories in that order. A supervisor will inspect each process and take construction photos.
7. Completion Inspection, Scaffold Dismantling & Handover We will confirm the finished work in the presence of the customer and provide construction photos, a report on the paints 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, Additional Work Approval, Inspection Reports

Equally important as the construction itself is “when, what, and with what materials we report”. At Kakeru Koumuten, we 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 restrictions on 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.

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

There are many large-scale repair contractors that cover Sakae 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, etc., 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 construction, having a leak warranty from the contractor ensures that repairs can be made at no cost, providing peace of mind! Companies that offer warranty periods are often confident in their work, making this 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 leak warranties. Some contractors also offer 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 responses for simple repairs like 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, as can warranties and aftercare services. Additionally, obtaining multiple estimates makes it easier to negotiate prices.

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! 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 difficult to assess visually, make sure to verify whether the repair method is appropriate for the condition of the substrate!

Check This on the Estimate (Checklist)

Check 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 based on the actual deterioration state and customer preferences.

In cases where a contractor completely outsources to subcontractors, they may lack knowledge and experience, leading to proposals for repairs in irrelevant areas or unnecessary 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 can be achieved at a reduced cost.

Additionally, contractors that outsource may be slow to respond if any troubles occur during construction. It is safer to avoid companies that do not actually meet with customers to manage 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 how the process proceeds.

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 imposed a total of 1.63788 billion yen in surcharge payment orders on 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).

※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 professionals or architects
• Document the vendor selection process in meeting minutes to ensure transparency
• Confirm the reasons for any 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 Sakae Ward, Yokohama

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

For condominiums, 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 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 construction records, 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 condominiums 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 and 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 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 breakage are observed, it is advisable to carry out 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 in the second and third repairs.

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

For apartments, the period is typically 3 weeks to 2 months, for small condominiums or buildings 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 windows, so we take thorough measures to minimize the impact on daily life, including distributing notifications before construction, 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 the establishment of the repair committee, building diagnosis, contractor selection, and general meeting resolutions, followed by 3 to 6 months for construction. Overall, it is advisable to plan for about 2 years to proceed with ample time. If using 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 Sakae Ward, Yokohama?

Neither Yokohama City nor Kanagawa Prefecture provides subsidies specifically for large-scale repair work. However, for condominium owners, if certain conditions are met, there are benefits such as a 50% reduction in fixed property tax under the “Condominium Longevity Promotion Tax System,” subsidies from Yokohama City for deterioration diagnosis and long-term repair planning (50% with a cap of 200,000 yen), and subsidies for barrier-free renovations in common areas (one-third with a cap of 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 program, so please check the eligibility conditions and application procedures for each program before contracting or starting construction.

I heard that fixed property tax can be reduced through 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 is over 20 years old and has 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 the equivalent of 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 Sakae Ward Office within three months of completion. For certified management plan condominiums, there are additional requirements such as raising repair reserve funds, so it is recommended to start preparations more than a year in advance.

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 “Mirai 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 it will not be implemented in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has started accepting bulk applications for collective housing from 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?

There are mainly four options: ① Postpone low-urgency work based on 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 financing from the Japan Housing Finance Agency. The agency’s condominium common area renovation loans do not require collateral, and interest rates 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. Sakae Ward is known for large-scale residential development centered around hilly areas from the 1960s to the early 1970s (according to the ward’s official page). For properties with many buildings, it is important to conduct deterioration diagnosis for each building, create a 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 condominiums with over 100 units as cost estimates and will propose multiple 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 space, 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 starting 2 to 3 months before construction begins.

Can I freely decide the color of the exterior walls?

In Sakae Ward, there are 10 building agreements listed by Yokohama City (Iijima “Hikarigaoka” area, Ofuna Midorigaoka Neopolis Kobe area, Hongodai Central Housing Area, Kamigou Neopolis, Shodoto 1st and 4th districts, Shodoto 1st district, Nomura Totsuka Hongodai Housing Area, Matsugaoka Housing Area, Kajigaya Housing Area, Shihirei Ue area), and there are district plans established in areas such as Sakae Nagao-dai, Ofuna Station North 1st district, Ofuna Station North 2nd district, Sakae Shonan Katsuradai district, Sakae Kosugegaya district, Sakae Kasama district, Sakae Katsuradai district, Sakae Hongodai district, Sakae Koyamadai district, and around Hongodai Station, as well as Sakae Kamigou Town district. The existence and content of agreements or plans regarding appearance and color vary by agreement and plan; for example, the district plans for Sakae Hongodai, Ofuna Station North 2nd district, and around Hongodai Station have regulations regarding form, design, and color. You can check what applies to your property through the public information on Yokohama City’s building agreements and district plans, and the Sakae Ward Office’s Urban Development Division (045-894-8335) also provides guidance on urban development in the ward. We will also investigate this during our survey. Sharing a color simulation of the completed image can facilitate discussions with neighbors and the community association.

Are there any differences in construction for buildings located in green areas or on slopes?

According to the ward’s materials, Sakae Ward is characterized by a terrain where the Itachi River and Kashio River form lowlands surrounded by hilly areas, with a green coverage rate of 38.8% (2nd in the city for the fiscal year 2019). For buildings on slopes or with elevation differences and retaining walls, special considerations may be needed for scaffolding installation and material transportation. Kakeru Koumuten Co., Ltd. has its own scaffolding team that checks the site and plans the transportation route and scaffolding layout. Additionally, for buildings close to trees, there is a higher likelihood of gutter and drain blockages due to fallen leaves, as well as moss and algae growth in shaded areas, so we focus on inspecting roof drains, drainage areas, exterior wall cleanliness, and waterproof layer damage. The degree of deterioration varies by building, so we conduct individual assessments during on-site surveys.

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

For buildings 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, but it incurs separate consulting fees, and caution is needed 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 specifying quantities, methods, and materials for each construction item, allowing you to compare with other companies on the same level.

How can I detect collusion in large-scale repairs?

There are three typical methods: ① Pre-determining the contractor and having other companies submit only formal high estimates as “dummy estimates,” ② A consultant contracts at an extremely low design supervision fee and receives 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 Construction Bid Agency Service.”

How many estimates should I obtain?

We recommend at least three companies. If there are too many, it becomes difficult to compare, and if there are too few, competition does not occur. What is important is not the number of companies but to “compare after creating the same playing field.” By creating a common specification sheet and quantity table and requesting under the same conditions, and making detailed breakdowns mandatory instead of accepting “one set” notation, it becomes clear whether the price difference is due to differences in range or unit price.

What is the difference if you have your own scaffolding?

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

I’m in the middle of obtaining estimates, but can I just have my estimate reviewed?

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

Can I request just emergency repairs 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 who are certified asbestos work supervisors and building material asbestos surveyors, and we handle everything from the legally required preliminary surveys to the roof overlay method and removal of asbestos-containing roofing materials. If there is sprayed asbestos, there is a possibility of receiving free surveys under Yokohama City’s countermeasures project and subsidies for two-thirds of the removal costs (up to 3 million yen), so we will provide information on that as well.

What happens if large-scale repairs are not done?

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 using full probing, etc., are required under certain conditions, such as when the exterior wall has exceeded 10 years since completion or exterior wall renovation. In Yokohama City, buildings that are only apartments are not designated as subject to periodic reporting, but mixed-use buildings that include stores require individual confirmation. Even if not subject to statutory surveys, 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, it is estimated to be between 2 million and 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it is estimated to be between 4 million and 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 at the same time as repairs to improve occupancy rates.

If you are looking for a large-scale repair contractor in Sakae 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 Sakae Ward. We are happy to respond not only to large-scale repair work but also to 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 lose in terms of cost, quality, and planning compared to other companies, so we welcome competitive estimates!

Large-Scale Repair Work Service Area

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

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