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

Large-Scale Repairs for Condominiums, Apartments, and Buildings in Isehara City

Large-scale repair work that can be handled in Isehara City

Large-scale repairs are not just “exterior wall painting” or “waterproofing,” but rather a project that addresses the overall deterioration of the building 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 processes.

Scope of Major Repairs Determined from Building Diagnosis

It is not always necessary to perform 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 items below 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 Repairs in Isehara City

The reason why we can take on large-scale renovations in Isehara City is partly because “Kakeru Koumuten has a base in Yokohama City”, but also because of our “unique initiatives in large-scale renovation work that cannot be imitated by other companies”, which have received high praise from many customers.

1. Equipment Specialized for Exterior Renovations

At Kakeru Koumuten, we have prepared the following warehouses and material storage areas to provide low-cost, high-quality exterior wall painting and waterproofing work for large-scale 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 performing scaffolding work with our own scaffolding team instead of outsourcing, we can cut costs on scaffolding work and provide quick and flexible responses.
We have approximately enough scaffolding materials for 100 single-family homes!

Storage of Materials in Our Large 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 provide swift responses even in emergencies!

In-house Waste Sorting

Large-scale renovations generate various waste materials such as leftover paint, metal, and wood. At Kakeru Koumuten, we sort and recycle waste materials in-house, leading to cost savings on waste disposal.

Showroom Dedicated to Exterior Renovations

In the showroom, not only can you have meetings, but you can also check actual samples and colors of exterior materials. Color simulations for exterior wall painting and heat resistance tests using a heat resistance 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 same person is responsible for sales and construction management, smooth communication is possible.

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

3. Various Permits and Skilled Workers

We have obtained construction business licenses and permits for industrial waste collection and transportation! We also have national certified sheet metal and painting technicians on staff, 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 investigators, so we can handle and conduct preliminary investigations of roofing materials containing asbestos.

4. Warranty and Aftercare

Most large-scale repair works, including “painting work,” “substrate repair work,” and “waterproofing work,” come with a warranty!
Aftercare 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 a drone! During leak investigations, we can use a thermal imaging camera to help identify the cause of leaks!

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

6. Human Resource Development

Our staff create various models to improve their skills and conduct practical training. Since different processing and techniques are required at each site, we regularly provide skill enhancement education to ensure each staff member can respond effectively. We also educate on points to be careful about and areas to check during each stage 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 notice boards in entrances to display progress charts and announcements! Additionally, we thoroughly educate entrants on manners to minimize inconvenience to residents and neighbors.

8. Strict Quality Control

Inspections are conducted by responsible personnel at each stage, along with detailed photographs of the work. We use film thickness testers and check sheets to ensure there are no oversights in inspections. During exterior painting and waterproofing work, we check the number of used paint cans to confirm that the specified amount of paint is being used, and we prevent construction defects by ordering paint in-house. Of course, we will also take photographs of used paint and report them.

9. Color Simulation for Exterior 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 changing to a two-tone color or making an image change, we hope to help enhance the stylish appearance and increase occupancy rates! Of course, we can also arrange paint samples for actual color confirmation.

*In Isehara City, there are areas with established rules for urban development, such as district plans. Since the regulations differ by district, prior confirmation of the exterior wall color may be necessary. Having a color simulation screen will help facilitate explanations at community meetings and general meetings.

9-2 Confirm the actual color with a trial paint!

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

9-3 Exterior renovation simulation

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

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

Cost Estimates for Major Repairs in Isehara City

The cost of major repairs varies significantly depending on the size of the building, its 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 cost estimates based on our construction performance by scale, and finally to examples of unit prices for each project.

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

According to a survey conducted by the Ministry of Land, Infrastructure, Transport and Tourism, which compiled 818 construction cases (FY 2021), approximately 70% of the costs for major repair work are concentrated in the range of 750,000 to 1,500,000 yen per unit, with the most common price range being 1,000,000 to 1,250,000 yen. Please 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 “Survey on Major Repair Work for Condominiums in FY 2021” (200 companies, 818 cases) *The amounts do not include consumption tax and common temporary costs. The percentages may not total 100% due to rounding and non-responses.

Breakdown of Construction Costs (Where the Money Goes)

Source: Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Renovation Work for Condominiums” (Second survey of large-scale renovation work. The overall average is 59.0% for construction-related, 22.3% for temporary structures, and 9.9% for miscellaneous expenses). *The total does not equal 100% because it includes equipment-related work, exterior works, and others. This is an average value and is not a criterion for judging the appropriateness of individual estimates.

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

*The above is an estimate based on Kakeru Koumuten’s construction performance and may vary depending on the presence of roofing work, steel work, plumbing, etc. For condominiums, please also use 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.

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

The estimate for large-scale renovations is broadly divided into “temporary structures,” “substrate repair,” “sealing,” “exterior wall painting,” “waterproofing,” and “miscellaneous expenses.” Before comparing total amounts, please check what each item includes, how much, and at what cost.

Unit Price Examples for Repair Work

*Costs and warranty periods vary based on shape, quantity, substrate condition, and type of materials. For 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 the next major repair will be 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. The rate of deterioration differs for each side based on location, sunlight, and ventilation, so confirming the condition of each side through an on-site survey and selecting paint suitable for the location can change durability.

Guidelines for Repair Reserve Funds and Options When Insufficient

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

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

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

Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Isehara City

Both Isehara City and Kanagawa Prefecture do not list subsidies specifically for large-scale renovation work in the publicly available list of grant systems. The available options can be broadly categorized into the following four types. The eligibility and application status of the systems may change even during the fiscal year, so please be sure to confirm with our company or the respective contact points before contracting or starting work.(As of October 8, 2026)

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

If large-scale repairs (including exterior painting, floor waterproofing, and roof waterproofing) that contribute to the longevity of condominiums meeting certain requirements are carried out, the fixed property tax amount for the residential portion will be reduced (up to the equivalent of 100㎡ per unit). The reduction rate is determined by each municipality. The reduction applies to the fiscal year with a tax assessment date of January 1 of the year following the completion of the work.

* The national leaflet shows the range of reduction rates as a nationwide system. The reduction rate and application destination for Isehara City could not be confirmed on the city’s official page. Please check with the City Asset Tax Division, Building and Depreciable Assets Section (Phone: 0463-74-5469) before the construction.

② Isehara City Condominium Management Support (For Management Associations, Start Here)

The contact point for condominium-related matters in Isehara City is the Urban Development and Housing Division, Housing Section (Phone: 0463-94-4782). On the city’s housing-related page, subsidies for the construction costs of large-scale repairs or construction grants for condominium owners could not be confirmed. The focus is on consultation and support for planning.

Source: Isehara City “Condominium Management Consultation (Reservation Required)” / Same “Housing”

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

This is a system certified by Isehara City. Upon certification, there are interest rate benefits for the “Condominium Common Area Renovation Loan” from the Japan Housing Finance Agency and Flat 35 (Maintenance and Preservation Type), which is also one of the requirements for the Long Lifespan Promotion Tax System (certification alone does not guarantee tax reduction). The certification requirements consist of 16 items from the national “Standards for Condominium Management.” The main criteria include holding a general meeting at least once a year, organizing management regulations, separating accounting for management fees and repair reserve funds, ensuring that the amount of arrears for more than three months is within 10% of the total, and “having a long-term repair plan that includes large-scale repair work at least twice and is created or reviewed within seven years with a planning period of 30 years or more.” Applications cannot be submitted directly to the city; instead, you must receive prior confirmation through the “Management Plan Certification Procedure Support Service” of the Public Interest Incorporated Foundation Condominium Management Center before applying through the system.

* There is no application fee for certification to the city. The system usage fee is 10,000 yen per application, and there is an additional examination fee for prior confirmation by a condominium management consultant.

④ National Energy Saving Support | Housing Energy Saving 2026 Campaign

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

Mirai Eco Housing 2026 Project

Advanced Window Renovation 2026 Project

⑤ Kanagawa Prefecture Subsidies (Application for Fiscal 2026 has Ended)

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

⑥ Financing System (Housing Finance Agency Mansion Sumairu Loan)

If the management association borrows funds for large-scale repairs, they 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 Isehara City

Isehara City is located almost in the center of Kanagawa Prefecture, bordering Hiratsuka City to the south, Hadano City to the west, and Atsugi City to the northeast. It covers an area of 55.56 km², with about one-third consisting of mountains and wilderness. The highest point is the summit of Mount Oyama at 1,251.70 meters, and the lowest point is 8.10 meters, with Mount Oyama being part of the Tanzawa-Oyama Quasi-National Park. The eastern part features plains, with the Suzukawa, Zenba River, Hinata River, and Utagawa flowing through, while the Tomei Expressway, National Route 246, and Odakyu Line run east-west. Due to the presence of mountain foothill villages, urban areas around Isehara Station, planned residential areas, and industrial parks within the same city, the way buildings deteriorate and the method of scaffolding can vary depending on the location.

Source: Isehara City “Population and Households of Isehara City” as of September 1, Reiwa 8 (estimated population)／Same “Introduction to the City”／Same “Notice of District Plans”

Buildings in Isehara City are divided into “four types”

In Isehara City, due to the different historical developments in various locations, not only the age of the buildings but also the location of the buildings (urban areas around Isehara Station, planned residential areas and housing complexes, industrial areas such as Suzukawa Industrial Park, and villages on the foothills of Mount Oyama) will affect the nature of the major repairs required in the next large-scale renovation. Please check which type your building falls into.

Source: Isehara City “Urban Master Plan Regional Concept” (Partially revised in March, Reiwa 7) / Same “Isehara City Landscape Plan and Landscape Ordinance”

Four Factors Unique to Isehara City That Damage Buildings

From the characteristics visible in Isehara City’s public documents, we have narrowed it down to four factors that are linked to large-scale repairs.

Source: Isehara City “Flood and Landslide Hazard Map” / Same “Internal Water Hazard Map Created” / Same “Urban Master Plan Regional Concept”

Key Points to Consider When Advancing Construction in Isehara City

*Kakeru Koumuten has five bases in Yokohama City and serves the entire Isehara area, including Isehara, Aiko-Ishida, Oyama, Takamori, Ishida, and Minami-Nomiya.

Signs of Deterioration Requiring Major Repairs and Timing

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 determination 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 is a reference example of guidelines and is not a uniform construction deadline. The actual cycle 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 “Survey on Actual Conditions of Large-Scale Renovation Work for Condominiums in Reiwa 3”

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 roof waterproofing for the renovation.

Exterior Renovation Work for Mixed-Use Building (Tile Wall Waterproofing + Roof Waterproofing)

Customer Feedback

Flow from On-Site Investigation to Completion of Work

From inquiry to completion of work and aftercare, a single 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 will allow for a smoother progression.

1. Contact Us (Free) Please reach out via phone, form, or LINE. If you have estimates from other companies, just presenting them is fine.
2. On-site Investigation & Building Diagnosis (Free) We will conduct a survey of the exterior walls, check for cracks, sealing, and waterproofing layers, and if necessary, investigate the rooftop, high places, and leak areas using drones or thermal imaging. For properties in Isehara City, we will check whether they are located near the station or along main roads, the distance to neighboring properties, the width of the road and delivery routes, pedestrian traffic, drainage, rust on metal parts, and the parking lot.
3. Investigation Report & Estimate Submission We will provide a deterioration diagnosis report with photos and an estimate detailing quantities, methods, and materials for each work item. Multiple plan proposals are also possible.
4. Plan Decision & Contract Confirm colors using color simulations, paint samples, and trial painting. For management associations, we can assist in preparing materials for general meetings. In areas subject to district planning, landscape planning, or building agreements, we will also explain the considerations for color choices.
5. Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors to greet them, and set up a bulletin board at the entrance (with a schedule and laundry information). If temporary relocation of parking is necessary, adjustments will be made at this stage.
6. Temporary Scaffold Installation & Various Works Our own scaffold team will set up scaffolding, followed by high-pressure washing → substrate repair → sealing → exterior wall painting & tile repair → waterproofing → metal parts & ancillary work in that order. A supervisor will inspect each stage and take construction photos.
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 paints used, and a warranty certificate.
8. Aftercare Maintenance We will send annual DM notifications, and inspections can be conducted every year. Simple repairs such as partial sealing are provided free of charge.

Resident Communication, Additional Work Approval, Inspection Reports

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 (chairperson, repair committee, etc.) and the estimated amount that requires approval before the contract.

How Will Life Be During Construction? Impact on Residents

For large-scale repairs, the principle is to proceed while residents remain in their homes. However, there will be restrictions on daily life while scaffolding is in place. Most troubles can be prevented by providing advance notice, so Kakeru Koumuten Co., Ltd. thoroughly explains and posts information before construction begins.

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

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

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 offers reassurance as a reference when you actually make a request.

Using ratings from Google and review sites can be effective when comparing large-scale repair contractors! Be cautious if there are many negative reviews. If there are few reviews, also check the construction track record, the content of explanations, and the 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 report the progress of the work and information about laundry on bulletin boards to prevent issues before they arise. Kakeru Koumuten Co., Ltd. specializes in exterior work, and we receive many requests for exterior renovations of apartments and condominiums.

Check for warranties 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 leak warranties. Some contractors also offer aftercare services separate from warranties, so be sure to check if warranties and aftercare services are available.

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

Obtain estimates from multiple contractors (at least 3 companies)

When requesting large-scale repairs, be sure to obtain estimates from multiple contractors. It is important to get estimates from at least 3 companies and compare their quotes and reports! Even for the same work, costs may vary between contractors, and warranties and aftercare services may differ. Additionally, obtaining multiple estimates makes price negotiations easier.

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

Check these points 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 condition 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 request a subcontractor after investigation, it may incur additional time and costs. By having knowledge and experience and managing in-house, responsible construction can be performed at a reduced cost.

Additionally, contractors that fully outsource may also have delayed responses in the event of any trouble 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, managed by knowledgeable and experienced personnel!

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

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

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 payment orders for a total of 1.63788 billion yen 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).

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

Three Typical Methods

Source: Ministry of Land, Infrastructure, Transport and Tourism “On the Proper Ordering of 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 unusually 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 Isehara City

How much does large-scale repair in Isehara City 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 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 or roofing work is required, so we will provide an estimate through a free on-site survey.

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 deterioration of sealing, tile lifting, or breaks in the waterproof layer 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 approximately 3 weeks to 2 months, for small condominiums or buildings 1.5 to 3 months, and for condominiums with more than 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 notices before construction, providing information on the schedule and laundry through bulletin boards, and strictly adhering to working hours.

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

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

Are there any subsidies available for large-scale repairs in Isehara City?

Neither Isehara City nor Kanagawa Prefecture currently lists subsidies specifically for large-scale repair work in the publicly available grant system. However, if it is a condominium, you may be able to use property tax reductions under the “Condominium Longevity Promotion Tax System” if certain conditions are met. The reduction rate is determined by each municipality, so please check with the Asset Tax Division of Isehara City. The city also offers free condominium management consultations (by reservation) and a management plan certification system. If the work includes windows and insulation, it may be eligible for “Advanced Window Renovation 2026” or “Future Eco Housing 2026.” The application timing and applicants vary by system, so please confirm the eligibility conditions and application procedures for each system before contracting or starting construction.

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

Yes, it is true if the 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 property tax for the residential portion can be reduced for up to 100 square meters per unit. This applies to work completed between April 1, 2023, and March 31, 2027, and a declaration must be made within three months of completion. The reduction rate is determined by each municipality, and since I could not find the rate or declaration destination for Isehara City on the official page, please check with the Asset Tax Division of the city (Building and Depreciable Assets Division, Phone: 0463-74-5469) before the work. For certified management plan condominiums, there are also requirements such as raising the repair reserve fund, which can take time to prepare, so it is recommended to start the process more than a year before construction.

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

The national “Childcare 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 the fiscal year Reiwa 7 and will not be implemented in the fiscal year Reiwa 8. The “Advanced Window Renovation 2026 Project” has started accepting bulk applications for apartment buildings from May 29, 2026 (application procedures will be handled by registered contractors). Please be careful not to establish financial plans based on outdated information.

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

There are mainly four options. ① Postpone low-urgency construction based on deterioration diagnosis to the next time, ② Review the scope and specifications of the work, ③ Check for support systems such as subsidies, ④ Consider increasing the repair reserve fund or financing from the Japan Housing Finance Agency. The Agency’s financing for apartment common area renovations does 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 earthquake-resistant construction. Please note that postponing waterproofing and tile peeling measures often ends up being more expensive, so please consult us for decisions on separation.

Can you handle large-scale repairs for complexes or large apartment buildings with many units?

We can discuss this. The urban master plan of Isehara City (regional concept) indicates that there is an increase in aging, vacant houses, and vacant lots in the eastern residential complexes, and there are also planned residential areas such as Osumidai. We accept consultations for properties with many buildings and units. For properties with many buildings, it is important to conduct deterioration diagnosis for each building, plan whether to carry out all buildings together or separate by building or year, and form consensus at the general meeting. Kakeru Koumuten Co., Ltd. also targets cost estimates for apartments with over 100 units and will provide proposals in a way that allows for comparison of multiple plans.

What happens to residents’ parking during construction?

Vehicles on the side where scaffolding is to be erected will need to be temporarily moved. In buildings with limited parking availability, 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?

The color of the building is generally decided by the management association or the owners; however, if there are district plans, landscape plans, or building agreements affecting the site, there may be restrictions on appearance and color. Isehara City is entirely within a landscape planning area, and construction of buildings or structures above a certain scale requires procedures based on landscape regulations before starting. The Oyama area has a landscape priority area (Oyama Townscape Preservation Area), and district plans are established in 14 areas within the city. Landscape plans can be consulted at the Urban Policy Division (phone 0463-94-4742). We will also investigate what applies to your site during our research. Sharing a color simulation to visualize the completed image can facilitate discussions with neighbors and the management association.

Are there differences in construction depending on the location, such as around the station, residential areas, industrial parks, or around Oyama?

Isehara City has different areas within the same city, including the urban area around Isehara Station, planned residential areas and housing complexes, industrial areas like Suzukawa Industrial Park, settlements in the Oyama and foothills, and low-lying rural areas. Depending on the location, there may be differences in road width, distance to neighboring properties, pedestrian traffic flow, and types of buildings (mixed-use buildings, wooden apartments, condominiums, complexes, factories, warehouses, etc.), which may require ingenuity in scaffolding installation and material delivery. Kakeru Koumuten Co., Ltd. has its own scaffolding team that checks the site and plans the delivery route and scaffolding layout. Additionally, the city publishes flood and landslide hazard maps, and there are designated landslide hazard areas in mountainous and hilly regions. We also focus on inspecting roof drains, drainage areas, and damage to waterproof layers. The degree of deterioration varies by building, so we will conduct individual assessments during the on-site survey.

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 medium and small-scale 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 attention must be paid to risks of conflicts of interest and collusion. Even with the responsibility construction method, verification of 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 you to compare them on the same level as other companies.

How can you 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 Consultants contract at extremely low design management fees and receive kickbacks from partner companies, creating a collusion. ③ Adding a portion of the contract amount as a back margin to the construction costs. Countermeasures include obtaining independent estimates, consulting with a neutral third party, documenting the selection process in meeting minutes, and including penalty clauses in contracts.

How many companies should I get estimates from?

We recommend at least three companies. Too many can make comparisons difficult, while too few may not foster competition. The important thing is not the number of companies but to “compare after creating the same playing field.” By creating a common specification sheet and quantity list and requesting under the same conditions, and requiring detailed breakdowns instead of “one set” notation, the differences in amounts can be clearly identified as differences in scope or unit prices.

What difference does it make if you have your own scaffolding?

Temporary construction accounts for about 20% of the construction costs in large-scale repairs (according to the Ministry of Land, Infrastructure, Transport and Tourism’s fiscal year 2021 survey). By not outsourcing scaffolding work, it is easier to control costs 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 approximately 100 single-family homes and plans scaffolding on-site according to site conditions.

Can I just have the estimate reviewed while in the middle of getting multiple estimates?

Of course, that’s possible. If you bring 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 multiple 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 inspectors 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 subsidies for investigation and removal costs in cases of sprayed asbestos may vary by year, so please check in advance with the municipal office. We will also provide guidance from the investigation stage.

What happens if large-scale repairs are not done?

There are risks such as personal injury from falling exterior tiles, structural deterioration due to corrosion of rebar, leaks, and a decrease in asset value. Furthermore, for buildings subject to regular reporting under Article 12 of the Building Standards Act, investigations through full tapping and other methods are required under certain conditions, such as when more than 10 years have passed since completion or exterior wall renovations for tile or mortar-finished walls. Buildings in Isehara City are overseen by Kanagawa Prefecture, and according to the list of regular reporting subjects published by the prefecture, condominiums are limited to “service-oriented housing for the elderly.” Mixed-use buildings that include stores require individual confirmation (Kanagawa Prefecture Building Safety Division Phone: 045-210-6257). 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 two-story wooden building with 6 to 10 units, it ranges from 2 million to 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it ranges from 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 use color simulations to change the appearance while repairing, aiming to improve occupancy rates.

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

Our company is based in Yokohama City and handles many exterior wall renovations and large-scale repairs for condominiums and apartments in Isehara City. We are happy to assist not only with large-scale repair work but also with partial repairs and leak repairs. In urgent cases such as leaks, we may be able to provide emergency measures, so please feel free to consult with us. “I want it to last a long time 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 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 comparative estimates!

Large-scale Repair Work Service Area

Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and Tokyo Metropolis.

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