Leave the repairs and renovations of condominiums and apartments in Ayase City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!

Large-Scale Repairs for Condominiums, Apartments, and Buildings in Ayase City, Kanagawa Prefecture

Large-scale renovation work available in Ayase City, Kanagawa Prefecture

Large-scale renovations 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 guaranteed that all of the above works will be performed. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten Co., Ltd., we conduct a free on-site survey to confirm the items below and compile a deterioration diagnosis report with photos, after which we will propose the scope of work.

Reasons Why Kakeru Koumuten is Chosen for Large-Scale Renovations in Ayase City, Kanagawa Prefecture

The reason we can be entrusted with large-scale renovations in Ayase City is our “initiatives that cannot be imitated by other companies in large-scale renovation work”, which have received high praise from 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, 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 for scaffolding work and enable quick and flexible responses.
We have approximately enough scaffolding materials for 100 single-family homes!

Storage of Materials in Our Large In-house 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, so we can ensure swift responses in emergencies!

In-house Waste Separation

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

Exterior Renovation Dedicated Showroom

In the showroom, not only can you have meetings, but you can also check actual samples and colors of exterior materials. Color simulations for exterior wall painting and thermal 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 inquiries to project completion, everything is managed by Kakeru Koumuten in a consistent system, allowing for high-quality large-scale renovations at reduced costs. Additionally, one representative will handle everything from the estimate to project completion. Since the same person is responsible for sales and construction management, smooth communication is ensured.

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 Obtained and Skilled Workers on Staff

We have obtained construction industry licenses and permits for industrial waste collection and transportation! We also have nationally certified sheet metal workers and painting workers on staff, and we are confident in our construction techniques. We can handle large-scale roofing projects such as those for factories! We also have qualified personnel for asbestos work supervisors and building materials containing asbestos inspectors, so we can manage 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 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 thermal imaging cameras to help identify the cause of leaks!

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

6. Human Resource Development

Our staff creates various models to enhance their skills and conducts practical training. Since different processing and techniques are required depending on the site, we regularly provide skill enhancement education to ensure each staff member can respond appropriately. We also educate on points to pay attention to and areas to check during each phase of large-scale repair work.

7. Consideration for Residents and Neighbors

During large-scale repair work, we not only notify residents and greet neighbors, but we also set up bulletin boards in entrances to display project schedules and notices! Additionally, we thoroughly educate visitors on proper manners to minimize any inconvenience to residents and neighbors.

8. Strict Quality Control

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

9. Color Simulation for Exterior Wall Painting

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 simulations on your smartphone or computer. By simulating and then applying a two-tone color or changing the image, we hope to help enhance the stylish appearance and increase occupancy rates! Of course, we can also arrange for paint samples to confirm the actual colors.

* Ayase City is entirely within a scenic area plan, and color standards for exteriors such as walls are set according to regional classifications (zoning, etc.). When deciding on colors, it is necessary to check for district plans and building agreements. Having a color simulation screen will help facilitate explanations to the general meeting, neighbors, owners, and residents smoothly.

9-2 Confirm actual colors with trial painting!

You can order samples of the paint you are considering and conduct trial painting on your exterior wall. By performing trial painting, 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 using accent materials such as cornices and louvers
・Simulation for roof painting and roof replacement work

With exterior renovation simulations, you can greatly reduce the risk of failure in changing your image! We hope that renovating the appearance of your apartment or condominium will help increase your occupancy rate.

Estimated Costs for Major Repairs in Ayase City, Kanagawa Prefecture

The costs for major repairs vary significantly depending on the size of the building, its deterioration condition, the scope of work, and the materials used. First, please refer to the national average based on public statistics, then to our company’s estimates based on construction performance by scale, and finally to examples of unit prices for each type of work.

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 aggregated 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. Note that the amounts in this survey do not include consumption tax and common temporary costs, so they differ from the current total construction costs including tax.

Source: Ministry of Land, Infrastructure, Transport and Tourism “FY 2021 Survey on Major Repair Works for Condominiums” (200 companies, 818 cases)　*Amounts do not include consumption tax and common temporary 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 Repair Work for Condominiums in FY2021” (Second aggregation of large-scale repair work. The overall average is construction-related 59.0%, temporary works 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 judging the appropriateness of individual estimates.

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

*The above is an estimate based on Kakeru Koumuten’s construction achievements and may vary depending on the presence of roofing work, steel work, plumbing, etc. For condominiums, please also consider the amount obtained by multiplying the above national statistics (750,000 – 1,500,000 JPY per unit) by the number of units as a reference.

Cost Breakdown for Temporary Works, Substrate Repairs, Exterior Walls, and Waterproofing

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

Examples of Unit Prices 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 correct.” 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. Choosing paints with anti-moss and anti-mold properties will improve durability in shaded and humid areas.

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 on Condominiums)

In the comprehensive survey of condominiums for the fiscal year Reiwa 5, 36.6% of management associations responded that “the repair reserve fund is insufficient compared to the plan.” There are four main options if there is a shortfall.

Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Ayase City, Kanagawa Prefecture

On the official website of Ayase City and Kanagawa Prefecture, no subsidies specifically targeting large-scale renovation work have been confirmed. The available options can be broadly divided into the following four types. The eligibility and application status of the systems may change even during the fiscal year, so please be sure to confirm with our company or each contact point before contracting or starting work. (As of October 8, 2026)

① Condominium Longevity Promotion Tax System (Property Tax Reduction)

If large-scale repairs (such as exterior painting, floor waterproofing, and roof waterproofing) that contribute to the longevity of certain qualifying condominiums are carried out, the property tax amount for the following year will be reduced by one-third (up to the equivalent of 100㎡ per unit; urban planning tax is not included). The reduction rate is determined by each municipality, and Ayase City is one-third.

② Management Plan Certification System (Entrance to Tax and Interest Rate Benefits)

This is a system certified by Ayase City, and receiving certification leads to reduced loan interest rates from the Japan Housing Finance Agency and meeting one of the requirements for the longevity promotion tax system (certification alone does not guarantee tax reduction). The city’s operation will start in April 2024, and the certification criteria are the same as the national standards (there are no unique standards for Ayase City). The main criteria include holding meetings at least once a year, maintaining management regulations, separate accounting for management fees and repair reserves, having overdue repair reserves of three months or less within 10% of the total, and “creating and reviewing a long-term repair plan that includes large-scale repair work twice or more within 30 years, within 7 years.”

*In Ayase City’s Condominium Management Improvement Promotion Plan (Fiscal Year 2024 – Fiscal Year 2034), it is stated that there is an expectation of a rapid increase in condominiums over 40 years old, and emphasis will be placed on awareness and dissemination of knowledge regarding management improvement.

③ National Energy Saving Support | Housing Energy Saving 2026 Campaign

Changes for 2026The “Child-Rearing Green Housing Support Project” for 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 Reiwa 7, and will not be implemented in Reiwa 8. Please be careful not to base your financial plans on outdated information.

Mirai Eco Housing 2026 Project

Advanced Window Renovation 2026 Project

④ Kanagawa Prefecture Subsidies (Applications for Fiscal Year 2026 have ended)

*The subsidy for existing housing energy efficiency renovation costs does not apply to common areas of rental apartments or units where the owner does not reside.

⑤ Financing System (Housing Finance Agency Mansion Sumairu Loan)

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

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

Cases Where Fire Insurance Can Be Used and Cases Where It Should Not Be Used

Building Conditions and Repair Points in Ayase City, Kanagawa Prefecture

Ayase City is located in the almost central part of Kanagawa Prefecture, about 40 km from the city center, covering an area of 22.14 km². According to the national census, the population surged from 12,611 in 1965 (Showa 40) to 50,367 in 1975 (Showa 50), and to 71,152 in 1985 (Showa 60) in a short period. Due to a concentrated period of housing construction, there is a tendency for “buildings constructed at the same time to reach the repair period simultaneously.” Additionally, the northeastern part of the city is home to the Atsugi Base, which occupies about 18% of the administrative area.

Source: Ayase City Website (Estimated Population)／Ayase City “Geography of Ayase City”／Ayase City Statistical Overview Reiwa 7 Edition “Land and Weather”／Ayase City Condominium Management Improvement Plan (March Reiwa 6)

Housing in Ayase City is Divided into “Four Layers”

According to the 2020 national census, out of the households in Ayase City, 23,214 were single-family homes (about 67%), and 10,821 were multi-family dwellings (about 31%). The table below shows the construction periods of all housing in the city, including single-family homes, alongside population movements based on the 2023 Housing and Land Statistical Survey. The type of major repairs that will be needed next will vary depending on which layer your building falls into.

Source: Ayase City Statistical Overview Reiwa 7 Edition “Census” (3-1・3-8) / Same “Civil Engineering and Construction” (14-12: As of October 1, 2023, Housing and Land Statistical Survey) *The number of homes may not match the total due to rounding in national statistics (in units of 10 homes). The age of buildings is an estimate calculated from the construction period classification.

Four Factors Influencing Buildings and Construction in Ayase City

Based on city statistics and public documents, we have organized four characteristics that lead to large-scale repairs. It is necessary to consider perspectives unique to the inland hilly areas, not just salt damage.

Source: Ayase City Statistical Handbook Reiwa 7 Edition “Land and Weather”／Geography of Ayase City／Ayase City Landscape Plan・Color Standards (PDF)・Key Landscape Formation Area Ayase Symbol Road／Ayase City “District Plan”・“Building Agreement”

Key Points to Consider When Advancing Construction in Ayase City

Source: Ayase City Statistical Overview Reiwa 7 Edition “Civil Engineering and Construction” (14-2 City Road Width Conditions) / Same “Land and Weather” (1-3 Land Use Area) / Same “National Census” (3-3 Daytime and Nighttime Population) *The ratios by width are based on the length of city roads (excluding bridges) and do not include private roads.

*We accept consultations for the entire Ayase City area, including Oogami, Ochiai, Kamitodana, Kozono, Tatekawa, Terao, Hayakawa, Fukaya, Yoshioka, and Ayase Nishi.

Signs of Deterioration and Timing for Major Repairs

Generally, major repairs are recommended 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 just the number of years, so if you observe any of the symptoms listed below, we recommend an early on-site inspection.

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 “Guidelines for Creating Long-Term Repair Plans” (Reiwa 6 June Revision – 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 for Mixed-Use Building (Tile Wall Waterproofing + Roof Waterproofing)

Customer Feedback

Process from On-Site Survey to Completion of Work

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

1. Inquiry (Free) Please contact us via phone, form, or LINE. If you have estimates from other companies, it is fine to just present those.
2. On-Site Survey & Building Diagnosis (Free) We will conduct a survey of the exterior walls, check for cracks, sealing, and waterproofing layers, and if necessary, investigate the rooftop, high places, and leak areas using drones or thermography. For properties in Ayase City, we will also check the site’s elevation differences, tree conditions, delivery routes, and parking.
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 plan proposals are also possible.
4. Plan Decision & Contract Confirm colors through color simulations, sample boards, and test painting. For management associations, we will assist in preparing materials for the general meeting. We will also explain color considerations in areas subject to landscape planning color standards, district planning, and building agreements.
5. Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors to greet them, and set up a bulletin board at the entrance (with project schedules 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 scaffolding team will set up the scaffolding, followed by high-pressure washing → substrate repair → sealing → exterior wall painting & tile repair → waterproofing → ironwork & ancillary work in that order. A supervisor will inspect and take photos at each stage.
7. Completion Inspection, Scaffold Dismantling & Handover We will confirm the finish in the presence of the customer and provide construction photos, a report on the paint used, and a warranty certificate.
8. Aftercare Maintenance We will send out annual DM notifications, allowing for yearly inspections. 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 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 during construction be? Impact on Residents

Large-scale repairs are principally carried out while residents remain in their homes. However, there will be limitations 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 begins.

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

There are many large-scale renovation contractors that cover Ayase City, Kanagawa Prefecture, 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 Renovations

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

Using Google and review sites to evaluate large-scale renovation contractors can also be effective! Be cautious if there are many negative reviews. If there are few reviews, also check the construction achievements, content of explanations, and management systems.

Large-scale repair work involves not only the construction itself but also the potential for conflicts 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 troubles before they occur. Kakeru Koumuten Co., Ltd. specializes in exterior work, and we receive many requests for exterior renovations of apartments and condominiums.

Check for Warranty and Aftercare Services

When choosing a large-scale repair company, 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! 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 a leak warranty. 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 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 estimates and reports! Even for the same work, costs can vary between contractors, and warranties and aftercare services may differ as well. 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 wall painting,” and “confirmation of the process” in detail! If the quality of the 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 from appearance alone, be sure to verify whether the repair methods are appropriate for the condition of the substrate!

Checklist: What to Look for in the Estimate

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 details will change based on the actual deterioration condition and customer preferences.

There are cases where contractors that completely outsource to subcontractors lack knowledge and experience, leading to proposals for repairs in irrelevant areas or unnecessary work. If you request a subcontractor after investigation, 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 to subcontractors may also have delayed responses in case of any troubles during construction. It is safer to avoid having a company that has not actually met with the customer manage the construction. Kakeru Koumuten performs everything from temporary scaffolding setup to exterior wall painting and waterproofing work in-house, with knowledgeable and experienced personnel managing the construction!

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

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

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

Latest 2026 In the large-scale renovation industry, inappropriate orders linked between design consultants and construction companies have long been a problem. The Ministry of Land, Infrastructure, Transport and Tourism issued warnings and notifications to management associations in January 2017 and April 2023, and on September 28, 2026, the Japan Fair Trade Commission announced that it had issued exclusion orders to 38 companies and a total of 1.63788 billion yen in surcharge payment orders to 37 companies regarding large-scale renovation work commissioned by condominium management associations in the Kanto region to design consulting firms (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: Ministry of Land, Infrastructure, Transport and Tourism “On the Appropriateness of Ordering Large-Scale Renovation 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 contractor selection process in minutes to ensure transparency
• Confirm the reasons for abnormally low consulting fees
• Include penalty clauses in contracts for cases of collusion
• Avoid concentrating information with a single consultant and verify specifications independently

Frequently Asked Questions about Large-Scale Repairs in Ayase City, Kanagawa Prefecture

How much does large-scale repair in Ayase City, Kanagawa Prefecture 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. Based on our 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. Costs may vary 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 the 12 to 15-year range. 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. In Ayase City, the number of condominiums over 40 years old is expected to increase, and during the second and third repairs, there tends to be a greater focus on tile repairs, replacement of iron parts, and updates to water supply and drainage pipes.

What is the construction period? Can residents stay during the work?

For apartments, the construction period 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, around 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 advance notices, providing information on the schedule and laundry on bulletin boards, and strictly adhering to working hours.

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

For management associations, it typically takes about 1 to 1.5 years for the establishment of the repair committee, building diagnosis, contractor selection, and general meeting resolutions, followed by 3 to 6 months for construction. Overall, it is advisable to plan for around 2 years to proceed comfortably. If you are using subsidies or tax incentives, obtaining management plan certification (resolutions at general meetings, pre-confirmation, and applications to the city) will also take time, so please factor that into your timeline.

Are there any subsidies available for large-scale repairs in Ayase City, Kanagawa Prefecture?

As of October 8, 2026, there are no confirmed subsidies specifically for large-scale repair work on the official websites of Ayase City and Kanagawa Prefecture. However, for condominium owners, if certain requirements are met, a one-third reduction in fixed property tax under the “Condominium Longevity Promotion Tax System” can be utilized. One of the requirements for this tax system is the management plan certification, which is operated by Ayase City. If the work includes windows and insulation, it may be eligible for “Advanced Window Renovation 2026” or “Future Eco Housing 2026.” The timing of applications and applicants varies by system, 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 through large-scale repairs; is that true?

Yes, it is true if the requirements 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 (such as exterior painting, floor waterproofing, and roof waterproofing as a package), the fixed property tax for the following year will be reduced by one-third for up to 100 square meters per unit (as per Ayase City’s reduction ratio). This applies to work completed between April 1, 2023, and March 31, 2027, and a declaration must be made to the taxation division of Ayase City Hall 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 changes. 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 association corporations can also become joint project participants, allowing for insulation renovations in common areas. Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in fiscal year 2025, and there will be no implementation in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has a method for collective applications for multi-family housing (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 main options are 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 the repair reserve fund or financing 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 scaffolding be set up even if there is a height difference on the site or if the front road is narrow?

Yes, it can be set up. Ayase City is a gently sloping hilly area with an elevation of about 15 to 80 meters, and approximately 77% of the city road has a width of less than 6.5 meters (as of March 31, Reiwa 7). The height difference and delivery routes vary for each building. Kakeru Koumuten Co., Ltd. owns its own scaffolding materials and has its own scaffolding team, allowing us to plan support for the boards, layout, and delivery routes after confirming the site. This is a part where additional costs are likely to arise after seeing the site, so it is important to confirm the delivery route during the estimation stage.

What happens to the parking spaces for residents during construction?

Vehicles on the side where scaffolding will be set up will need to be temporarily moved. The number of parking spaces and availability varies by building, and depending on the availability of nearby parking lots, it may take time to secure a relocation spot. Kakeru Koumuten Co., Ltd. will coordinate with you, including checking the availability of nearby coin parking and monthly parking lots, starting 2 to 3 months before construction begins.

Can I freely decide the color of the exterior walls?

Ayase City is entirely within a landscape planning area, and color standards (hue, brightness, and saturation ranges) for exterior walls and other elements are set for each regional classification (zoning, etc.). The Ayase Symbol Road, which is part of the urban planning road Terao Kamidana Line, has different standards as a key landscape formation area. Additionally, there are seven district plans and one building agreement published on the city’s page. Whether a notification is required depends on the size of the building and the content of the work, so please check in advance with the city’s Urban Development Division (0467-70-1701). We will also investigate this during our survey. Sharing a color simulation to visualize the completed image can facilitate discussions at meetings and with neighbors.

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

This is because areas with poor sunlight and trapped moisture are prone to the growth of algae, moss, and mold. In addition to the north side, areas that do not receive sunlight due to neighboring buildings or trees are also likely to be affected. By thoroughly removing them with high-pressure washing and choosing paint with anti-algae and anti-mold properties, recurrence can be minimized. We also recommend checking for blockages in roof drains and gutters caused by leaves and mud, as these can lead to puddles on the roof and cause leaks.

Which method should I choose: responsibility construction method or design supervision method?

As of Reiwa 5, there are 62 condominium buildings and 2,357 units in Ayase City, with an average size of about 38 units per building. The smaller the number of units, the heavier the burden of consulting fees, so we believe that the responsibility construction method is often suitable for such 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, consulting fees are incurred separately, and there are risks of conflicts of interest and collusion that need to be considered. Even with the responsibility construction method, verifying price, specifications, and construction status is essential. Kakeru Koumuten Co., Ltd. provides estimates that clearly state quantities, methods, and materials for each construction item, allowing for comparison on the same level as other companies.

How can I detect collusion in large-scale repairs?

There are three typical methods: ① Pre-determining the contractor and having other companies submit only formal high estimates, known as “dummy estimates,” ② A consultant contracts at an extremely low design supervision fee and receives kickbacks from affiliated contractors, leading to collusion, ③ Adding a portion of the contract amount as a back margin to the construction costs. Countermeasures include obtaining independent estimates, consulting with neutral third parties, documenting the selection process in meeting minutes, and including penalty clauses in contracts. On September 28, 2026, the Japan Fair Trade Commission announced exclusion orders and payment orders for surcharges related to large-scale repair work.

How many companies should I get estimates from?

最低3社をおすすめします。多すぎると比較しきれず、少なすぎると競争が働きません。大切なのは社数よりも「同じ土俵を作ってから比べること」です。共通の仕様書や数量表を作って同一条件で依頼し、「一式」表記を認めず内訳明細を必須にすると、金額差が範囲の違いなのか単価の違いなのかがはっきりします。

What is the difference if we have our own scaffolding?

In large-scale repair projects, temporary construction accounts for about 20% of the total cost (according to the Ministry of Land, Infrastructure, Transport and Tourism’s FY2021 survey). By not outsourcing scaffolding work, we can easily control costs in this area, and our in-house scaffolding team can flexibly respond to sudden changes in the schedule or additional work. Kakeru Koumuten Co., Ltd. owns scaffolding materials for approximately 100 detached houses, and we plan according to the site conditions, even in locations with elevation differences or narrow front roads.

I’m in the middle of getting multiple estimates; can I just have a look at your estimate?

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

Can I request just 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 as asbestos work supervisors and building material surveyors for asbestos-containing materials. We handle everything from the legally required preliminary surveys to the roof overlay method and removal of asbestos-containing roofing materials. The availability of municipal subsidies for the investigation and removal of sprayed asbestos varies by municipality, so please check with the Ayase City office.

What happens if large-scale repairs are not done?

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, buildings subject to regular reporting under Article 12 of the Building Standards Act require investigations through comprehensive probing under certain conditions, such as when more than 10 years have passed since completion or exterior wall renovations for tiled or mortar-finished walls. Ayase City is an area governed by Kanagawa Prefecture, and for apartment buildings, only service-equipped housing for the elderly is subject to this requirement. Mixed-use buildings, including stores, restaurants, hospitals, and hotels, may also be subject depending on their location and scale, so individual confirmation is necessary. Even if not subject to statutory investigations, regular inspections and maintenance are essential, so please consult us if you are unsure about your judgment.

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

For a wooden two-story building with 6 to 10 units, the estimate is around 2 million to 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it is around 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 to carry out repairs for apartments every 10 to 15 years. For owners, there is an increasing trend to change the appearance through color simulations at the same time as repairs to improve occupancy rates.

If you are looking for a large-scale repair contractor in Ayase City, Kanagawa Prefecture, contact Kakeru Koumuten Co., Ltd.

We handle exterior wall renovations and large-scale repairs for condominiums and apartments in Ayase City, as well as throughout Kanagawa and Tokyo. We are happy to assist not only with large-scale repair work but also with partial repairs and leak repairs. Whether you want to make it last longer with one renovation, keep costs down as much as possible, or 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 organization, 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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