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

Large-Scale Renovations for Condominiums, Apartments, and Buildings in Miyamae Ward, Kawasaki City

Large-scale renovation work available in Miyamae Ward, Kawasaki City

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 the work listed below with our own team, ensuring clear responsibility and coordination of the process.

Scope of Major Repairs Determined by Building Diagnosis

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

Reasons Kakeru Koumuten is Chosen for Large-Scale Repairs in Miyamae Ward, Kawasaki City

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

1. Equipment Specialized for Exterior Renovations

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

In-house Scaffolding Materials

We own the scaffolding materials necessary for temporary scaffolding required for large-scale repairs and can assemble the scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can cut costs related to scaffolding work and provide quick and flexible responses.
We own scaffolding materials for approximately 100 detached houses!

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, allowing for swift responses in emergencies!

In-house Waste Sorting

Large-scale repairs generate various types of waste, including leftover paint, metal, and wood. At Kakeru Koumuten, we sort and recycle waste in-house, contributing to cost reduction in waste disposal.

Showroom Dedicated to Exterior Renovations

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

2. Cost Reduction through In-House Management and Construction

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

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

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

3. Various Permits and Skilled Workers

We have obtained construction business licenses and permits for industrial waste collection and transportation! We also have nationally certified sheet metal and painting skilled workers, and we are confident in our construction techniques. We can also handle large-scale roofing work for factories! We have qualified personnel for asbestos work supervisors and building material asbestos surveyors, so we can handle asbestos-containing roofing materials and pre-investigations as well.

4. Warranty and Aftercare

Large-scale repair work comes with warranties for most projects, including “painting work,” “substrate repair work,” and “waterproofing work”!
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 rain 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 rain leaks! We will respond quickly to urgent requests!

6. Staff Development

Our staff create various models for skill improvement and conduct practical training. Since different processing and techniques are required at the site, we regularly provide skill enhancement education to ensure each staff member can respond appropriately. We also educate on points to be careful of 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 notice boards at entrances to display project schedules and announcements! Additionally, we thoroughly educate entrants on manners to minimize 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 equipment and check sheets to ensure there are no oversights in inspections. During exterior wall painting and waterproofing work, we check the quantity of used paint cans to confirm that 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 used paint and report them.

9. Exterior Wall Painting Color Simulation

9-1 Self Color Simulation

The simulations created by our company can be done using actual photos of your apartment or building!You can also perform simulations on your smartphone or computer. By simulating and then changing to a two-tone color or altering the image, 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 Miyamae Ward, there are district planning areas (5 districts) and specific areas for landscape planning (Saginuma Station area). When changing the color of the exterior walls, there may be procedures and color standards established. There may also be areas with building agreements. Having a color simulation screen can make explanations at the management association’s general meetings and neighborhood associations proceed smoothly.

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

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

9-3 Exterior renovation simulation

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

With exterior renovation simulations, 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 Large-Scale Repairs in Miyamae Ward, Kawasaki City

The cost of large-scale 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 market price based on public statistics, then to our company’s cost estimates based on our construction records categorized by size, 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 compiled 818 construction cases (FY 2021), approximately 70% of the costs for large-scale repairs are concentrated in the range of 750,000 to 1,500,000 yen per unit, with the most common price range being 1,000,000 to 1,250,000 yen. Please note that the amounts in this survey do not include consumption tax and common temporary construction costs, so they differ from the current total construction costs including tax.

Source: Ministry of Land, Infrastructure, Transport and Tourism “FY 2021 Survey on Large-Scale Repair Work for Condominiums” (200 companies, 818 cases)　*The amounts do not include consumption tax or common temporary construction costs. The percentages do 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 Repair Work for Condominiums” (Second survey of large-scale repair work. The overall average is 59.0% for construction-related costs, 22.3% for temporary works, and 9.9% for miscellaneous expenses). *The total does not equal 100% because it includes equipment-related work, exterior works, and others. This is an average value and not a criterion for judging the appropriateness of individual estimates.

Cost Estimates by Building Size (Scaffolding, Substrate Repair, Exterior 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, metal work, plumbing, etc. For condominiums, please also use the above national statistics (750,000 – 1,500,000 JPY per unit) multiplied by the number of units as a guideline.

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

The estimate for large-scale repairs is broadly divided into “temporary works,” “substrate repair,” “sealing,” “exterior 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 years 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 to conduct the next major repair with the durability of the materials to avoid waste.

* The estimated lifespan is a general guideline and may vary depending on sunlight, location, and the condition of the substrate. For areas exposed to strong rain, wind, and sunlight, choosing high-weather-resistant paint and specifications that include rust prevention for metal parts after cleaning will change durability.

Guideline for Repair Reserve Funds and Options When Insufficient

The Ministry of Land, Infrastructure, Transport and Tourism guidelines indicate the guideline for repair reserve funds 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 Fiscal Year Comprehensive Survey on 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 it is insufficient, there are four main options.

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

Both Kawasaki City and Kanagawa Prefecture do not have subsidies specifically for large-scale renovation work itself (Kawasaki City has indicated that there are no subsidies for renovation work aimed at exterior wall painting or roof repairs). The available options can be broadly categorized into the following four types. The eligibility and application status of the systems may change 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 (Reduction of Fixed Property Tax)

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

② Support for Apartment Management in Kawasaki City: Subsidies by Purpose (For Management Associations, Start Here)

Kawasaki City has a “Kawasaki City Apartment Management Association Registration and Support System” (Free Registration). By registering, you will receive the “Apartment Newsletter,” and the number of advisor dispatches will also increase. Management associations that have not yet registered, this is your starting point.

Source: Kawasaki City “Support System for Condominium Management Associations” ／ Kawasaki City Housing Subsidy System Information ／ Sprayed Asbestos Subsidy System ／ EV Charging Infrastructure Subsidy (for Multi-Family Housing) ／ Reiwa 8 Fiscal Year Solar Power Generation Equipment Installation Subsidy　*The status of applications and maximum amounts for barrier-free and seismic grants are not listed on the city’s page.

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

This is a system certified by Kawasaki City. Upon certification, you may receive interest rate benefits for the “Condominium Common Area Renovation Loans” from the Japan Housing Finance Agency and Flat 35 (Maintenance Type), and it is also one of the requirements for the Long-Life Promotion Tax System (certification alone does not guarantee tax reduction). The main criteria include holding general meetings at least once a year, establishing management regulations, separate accounting for management fees and repair reserves, overdue amounts of three months or more being within 10% of the total, and “having a long-term repair plan that includes two or more large-scale repair works within the remaining period of 30 years, created or reviewed within the last 7 years.” Additionally, registration in the city’s registration and support system is required.

*The registration fee and certification application fee for Kawasaki City are free (separate costs apply for prior confirmation). The validity period of the certification is 5 years. Applications proceed in the order of resolution at the general meeting, prior confirmation through the “Management Plan Certification Procedure Support Service,” and city registration.

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 (Applications for Fiscal 2026 have ended)

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

⑥ Financing System (Housing Finance Agency Condominium Sumairu Loan)

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

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

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

Building conditions and repair points in Miyamae Ward, Kawasaki City

Miyamae Ward, Kawasaki City, is located in the northwest part of Kawasaki City and is characterized by hilly terrain surrounded by the Tama Hills. According to city documents, the area has a highly undulating topography consisting of hills, slopes, and valleys. Historically a rural area, Miyamae Village and Mukogaoka Village were established with the enforcement of the town and village system in 1889 (Meiji 22), and the ward name is derived from Miyamae Village. The opening of the Tokyu Den-en-toshi Line between Mizonokuchi and Nagatsuta in 1966 (Showa 41) and the establishment of the Tomei Expressway’s Tomei Kawasaki Interchange in 1968 (Showa 43) led to a rapid increase in population and urbanization as a suburban residential area within 30 km of central Tokyo. In July 1982 (Showa 57), it was separated from Takatsu Ward to become Miyamae Ward. City documents indicate that there are areas where more than 50 years have passed since development, and it is expected that buildings will age significantly. The different characteristics of areas around the Den-en-toshi Line stations, residential areas in hilly regions, and low-lying lands along rivers within the ward serve as a starting point for considering large-scale repairs in Miyamae Ward.

Source: Kawasaki City “Population Report” (Estimated as of September 1, Reiwa 8)／Kawasaki City “Population by Age” (As of October 1, Reiwa 2)／Miyamae Ward “Overview of Miyamae Ward”／Kawasaki City “Miyamae Ward Overview, Situation, Characteristics”／Kawasaki City “District Planning List”　*The ranking is based on the numerical values in the table, with the elderly population ranked from the highest districts, and others ranked from the most populous districts.

Let’s also check the composition of generations and households. The percentage of the elderly population (65 years and older) in Miyamae Ward is 21.3% (Reiwa 2), ranking fourth among the seven wards in Kawasaki City, while the percentage of the young population (under 15 years old) is 13.7%, the highest, and the percentage of the working-age population (15-64 years old) is 65.1%, ranking fifth. Calculating from the population and number of households, there are about 2.2 people per household. These figures represent the entire ward and do not indicate the situation of individual building residents. According to city documents, the 2015 census showed a daytime-to-nighttime population ratio of 73.4%, the smallest in the city, indicating that the daytime population is less than the nighttime population. According to ward data from 2005, the number of children under 18 is the highest among the seven wards, and the composition of generations varies by location within the same ward.

Buildings in Miyamae Ward are divided into “three faces”

The buildings in Miyamae Ward reflect the history of the opening of the Den-en-toshi Line and the development of residential areas in hilly regions, which have become characteristics of each location. The type of heavy construction work required for the next major repair will vary depending on where your building is located. Please note that the history of rebuilding or major renovations differs for each building, so the age of the building should be viewed as a guideline.

Source: Miyamae Ward “Overview of Miyamae Ward” (Updated September 2, 2026. Division in 1982, opening of the Den-en-toshi Line in 1966, establishment of the Tomei Kawasaki Interchange in 1968, Hirase River basin) / Kawasaki City “Overview, Situation, and Characteristics of Miyamae Ward” (Published in 2008. Origin of the ward name, development as a suburban residential area) / Kawasaki City “Current Situation and Main Issues of Miyamae Ward (Phase 1)” (Published in 2005. Hilly terrain and slopes) / Kawasaki City “Current Situation and Main Issues of Miyamae Ward (Phase 2)” (Published in 2008. Rivers and greenery, number of children) / Kawasaki City “Current Situation and Considerations for Redevelopment in Miyamae Ward” (PDF, no date provided) (Topography of hills, slopes, and valleys, areas over 50 years since development, daytime and nighttime population ratios) / Kawasaki City “Town Development Around Saginuma Station” (Updated January 22, 2026) / Kawasaki City “Specific Areas of the Landscape Plan” / Kawasaki City “District Plan List” / Kawasaki City “Flood Hazard Map” *Descriptions in the ward’s materials may include information from around 2005 and 2008, which may differ from the current situation.

Four Factors Unique to Miyamae Ward That Damage Buildings

The contents of large-scale repairs vary depending on the location of the building. When investigating buildings in Miyamae Ward, the following four factors are particularly important to confirm. I will discuss based on the overall trends in the ward, but the actual condition varies by building, so it is essential to check on-site.

Source: Kawasaki City “Current Situation in Miyamae Ward and Considerations for Redevelopment” (PDF, no date specified) / Kawasaki City “Landslide Hazard Map” / Kawasaki City “Urban Development around Saginuma Station” / Kawasaki City “Overview of the Announcement of the Decision on the First-Class Urban Redevelopment Project (Saginuma Station Front Area)” (September 6, 2023) / Kawasaki City “Specific Areas of the Landscape Plan” / Kawasaki City “District Planning List” / Kawasaki City “Flood Hazard Map”・“Internal Water Hazard Map” / Kawasaki City “Current Situation and Main Issues in Miyamae Ward (Phase 2)” (published in 2008) / Kawasaki City “Building Agreements” *Descriptions in district materials include those from around 2005 and 2008.

Key Issues to Address in Miyamae Ward During Construction

* Kakeru Koumuten has five locations, including a showroom and material storage, in Yokohama City, and we respond to consultations throughout Miyamae Ward, including Saginuma, Miyamaedaira, Miyazaki, Arima, Nogawa, and Sugou.

Signs of Deterioration Requiring Major Repairs and Timing

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

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

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

Source: Ministry of Land, Infrastructure, Transport and Tourism “Long-term Repair Plan Creation Guidelines” (Revised June 2024, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “FY2021 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 renovated it by combining clear waterproofing for the tile exterior wall and waterproofing for the roof.

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

Customer Feedback

Flow from On-site Inspection to Completion of Construction

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

1. Contact Us (Free) Please reach out to us via phone, form, or LINE. If you have estimates from other companies, it’s fine to just present those.
2. On-site Investigation & Building Diagnosis (Free) We will conduct a survey of the exterior walls, check for cracks, sealing, and waterproofing layers, and if necessary, investigate the rooftop, high places, and leak areas using drones or thermal imaging. For properties in Miyamae Ward, we will also check for rust on iron parts, potential flooding, internal water, and landslide risks, as well as the condition of slopes and retaining walls, and confirm the delivery route and parking.
3. Submission of Investigation Report & Estimate We will provide a deterioration diagnosis report with photos and an estimate detailing quantities, methods, and materials for each work item. We can also propose multiple plans.
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 procedures and color considerations.
5. Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors to greet them, and set up a bulletin board at the entrance (with a schedule and laundry information). If temporary relocation of parking is necessary, we will coordinate this at this stage.
6. Temporary Scaffold Installation & Various Works Our own scaffold team will set up the scaffolding, followed by high-pressure washing → substrate repair → sealing → exterior wall painting & tile repair → waterproofing → iron parts & ancillary work in that order. A responsible person will inspect each process 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 out annual DM notifications, and inspections can be conducted every year. Simple repairs like partial sealing are provided free of charge.

Resident Communication, Additional Work Approval, Inspection Reports

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

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

How Will Life Be During Construction? Impact on Residents

Large-scale repairs are principally carried out 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 prior notice, so Kakeru Koumuten Co., Ltd. thoroughly explains and posts information before construction begins.

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

There are many large-scale repair contractors that cover the Miyamae area of Kawasaki 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 peace of mind as a reference when you actually request work.

Using ratings from Google and review sites can be effective when comparing large-scale renovation 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 renovation 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 renovation 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.

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

When comparing estimates, consider not only the cost but also the “items in the estimate,” “methods and materials for substrate repair and exterior wall painting,” and “confirmation of the process” to make a detailed judgment! If the quality of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price. Especially since substrate repair work can be difficult to assess visually, 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 details will change based on the actual deterioration state 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 can be performed at a reduced cost.

Additionally, contractors that outsource to subcontractors may also have delayed responses in case 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 installation to exterior wall painting and waterproofing work in-house, managed by knowledgeable and experienced personnel!

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

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

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

Latest 2026 In the large-scale renovation industry, inappropriate orders linked between design consultants and construction companies have long been a problem. The Ministry of Land, Infrastructure, Transport and Tourism issued warnings and notifications to management associations in January 2017 and April 2023, and on September 28, 2026, the Japan Fair Trade Commission announced that it had issued exclusion orders to 38 companies and a total of 1.63788 billion yen in payment orders to 37 companies regarding large-scale renovation work commissioned by condominium management associations 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 Proper Ordering of Large-Scale Repair Work for Condominiums” (Notification dated April 3, Reiwa 5, PDF)

Self-Defense Measures for Management Associations

• Obtain independent estimates from multiple companies
• Consult with neutral third parties such as condominium management professionals or architects
• Document the vendor selection process in minutes to ensure transparency
• Confirm the reasons for unusually low consulting fees
• Include 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 Miyamae Ward, Kawasaki City

How much does large-scale repair in Miyamae Ward, Kawasaki 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 company’s construction records, the estimate for a two-story wooden apartment is between 2,000,000 and 4,000,000 yen, for a three-story steel or RC apartment between 4,000,000 and 9,000,000 yen, and for small condominiums or mixed-use buildings between 5,000,000 and 15,000,000 yen. The costs vary depending on the condition of the substrate and whether waterproofing and roofing work is needed, so we provide free on-site estimates.

How often should large-scale repairs be conducted?

Generally, a cycle of 12 to 15 years is recommended, and the actual cycle is most commonly 13 years according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey, with about 70% falling within 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 there are signs of deterioration in the sealing, lifting of tiles, or breaks in the waterproof layer, it is advisable to carry out repairs without waiting for the cycle, as this can ultimately reduce costs. In older buildings, the proportion of tile repairs and iron part replacements tends to increase in the second and third rounds of repairs.

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

The estimated duration is about 3 weeks to 2 months for apartments, 1.5 to 3 months for small condominiums and buildings, and about 4 to 6 months for condominiums with more than 50 units. 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, such as distributing notices before construction, providing information on the schedule and laundry through bulletin boards, and strictly adhering to work 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 using subsidies or tax incentives, please include the time for obtaining management plan certification (resolutions at general meetings, prior confirmations, and applications to the city) in your timeline.

Are there any subsidies available for large-scale repairs in Miyamae Ward, Kawasaki City?

Neither Kawasaki City nor Kanagawa Prefecture offers subsidies specifically for large-scale repair work (Kawasaki City has indicated that there are no subsidies for exterior wall painting or roof repairs aimed at renovations). However, for condominium owners, if certain conditions are met, a 50% reduction in fixed property tax can be applied under the “Condominium Longevity Promotion Tax System.” Additionally, Kawasaki City offers free consultation services and advisor dispatch (up to 3 times for registered management associations), grants for resolving step differences in common areas (one-third of the costs), subsidies for the investigation and removal of sprayed asbestos, and subsidies for EV charging facilities and solar power/storage batteries for multi-family housing. If the work includes windows and insulation, it may qualify for “Advanced Window Renovation 2026” or “Future Eco Housing 2026.” The application timing and applicants vary by system, so please check the eligibility conditions and application procedures for each system before contracting or starting work.

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

It is true if the conditions are met. Under the Condominium Longevity Promotion Tax System, if a condominium that meets the requirements (20 years or older and with more than 10 units) conducts large-scale repairs that contribute to longevity (including exterior wall painting, floor waterproofing, and roof waterproofing), the fixed property tax for the following year can be reduced by half for one unit equivalent to 100 square meters. This applies to work completed between April 1, 2023, and March 31, 2027, and a declaration must be made within three months of completion to the city tax office or tax division responsible for the building’s location (in Miyamae Ward, this is the Mizonokuchi City Tax Office). For certified management plan condominiums, there are additional 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 the construction.

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

There is. The national “Child-Rearing Green Housing Support Project” has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Management associations and management corporations can also become joint contractors, allowing for insulation renovations in common areas. Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in the fiscal year 2025 and will not be implemented in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has started accepting bulk applications for apartment buildings from May 29, 2026 (the application process is 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 loans from the Japan Housing Finance Agency. The Agency’s loan for common area renovations in condominiums 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 seismic work. Please note that postponing waterproofing and tile peeling measures often ends up being more expensive, so please consult us for judgment on separation.

Can scaffolding be set up on sloped or uneven land?

Yes, it can. Miyamae Ward is located in a corner of the Tama Hills, characterized by a terrain with hills, slopes, and valleys. There are buildings constructed on sloped and terraced land. Kakeru Koumuten Co., Ltd. owns its own scaffolding materials and has its own scaffolding team, allowing for planning of support and layout of the boards after confirming the site. This is an area where additional costs are likely to arise after seeing the site, so it is important to check the delivery route during the estimation phase. We also check the deterioration of retaining walls and slopes and consult on whether they are included in the long-term repair plan.

What will happen to the parking for residents during construction?

Vehicles on the side where scaffolding will be erected will need to be temporarily moved. In buildings with many units or those with on-site parking, securing a relocation spot may take time depending on the number and arrangement of vehicles. Kakeru Koumuten Co., Ltd. will coordinate with you about the availability of nearby coin parking and monthly parking starting 2 to 3 months before construction begins.

Can I freely decide the color of the exterior walls?

This depends on the regulations that apply to the property. There are five districts in Miyamae Ward that have district planning areas, and the Saginuma Station area is a designated area for landscape planning. There may also be areas with building agreements that stipulate the colors and uses of the exterior. The details vary by district. You can check what applies to your property at the Kawasaki City district planning, landscape planning, and building agreement office. We will also investigate this during our research and share the completed image through color simulations to assist in consensus building with the management association and neighbors.

Miyamae Ward is far from the sea, but are there any concerns regarding damage to the exterior walls and metal parts?

Miyamae Ward is an inland ward not facing the sea, so salt damage from sea breezes is not a major concern. On the other hand, city documents describe Miyamae Ward as having a terrain with hills, slopes, and valleys, and there is a hazard map for landslides specific to Miyamae Ward in Kawasaki City. There is also a flood and internal water hazard map specific to Miyamae Ward. The assumptions vary by property, so please check your own site. In areas around stations and residential areas, considerations for the dispersion of washing, the smell of paint, and the noise of deliveries are also essential. We will check the progression of rust on metal parts, the condition of sealing and waterproof layers, and around drains during the on-site survey, and we will specify the necessary scope in the estimate regarding waterproofing around the first floor, basement, and mechanical rooms, as well as the condition of retaining walls and slopes.

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

In smaller buildings, the burden of consulting fees increases, so we believe that the responsibility construction method is often more suitable for small to medium-sized buildings. The design supervision method allows for comparison of construction companies under the same conditions since a third party creates the specifications; however, 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 detailed estimates that specify quantities, methods, and materials for each construction item, allowing you to compare with other companies on the same level.

How can I detect collusion in large-scale repairs?

Typical methods are three: ① Deciding on a contractor in advance and having other companies provide only formal high estimates, known as “dummy estimates,” ② Consultants contract at extremely low design management fees and receive kickbacks from partner companies, creating collusion, ③ Adding a portion of the contract amount as a back margin to the construction costs. Countermeasures include obtaining independent estimates, consulting a neutral third party, documenting the selection process in minutes, and including a penalty clause in the contract.

How many companies should I get estimates from?

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

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

In large-scale repair construction, 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, it is easier to 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 about 100 single-family homes and plans according to the site conditions, even on slopes or uneven terrain.

I’m in the middle of getting estimates; can I just have my estimate reviewed?

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

Can I request just emergency measures for a leak?

Yes. As a preliminary step before large-scale repairs, we also accept requests for emergency measures for leaks or partial repairs. 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 cover methods and removal of asbestos-containing roofing materials. If there is sprayed asbestos, there may be a possibility to use the Kawasaki City subsidy program (the cost for the survey is 100% covered up to 150,000 yen, and for removal work, 2/3 of the cost is covered up to 3,000,000 yen. Contracts made before the grant decision are not eligible), so we will provide guidance on that as well.

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, buildings subject to regular reporting under Article 12 of the Building Standards Act require investigations through full probing, etc., under certain conditions, such as when more than 10 years have passed since completion or exterior wall renovations for tile or mortar-finished walls. While the list of regular reporting target uses in Kawasaki City does not include collective housing (apartments), for mixed-use buildings that include stores, the judgment varies based on the use and area per floor, 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 between 2,000,000 and 4,000,000 yen, and for a three-story steel or RC building with 10 to 20 units, it is between 4,000,000 and 9,000,000 yen based on our company’s track record (including scaffolding, substrate repairs, exterior wall painting, sealing, and waterproofing). It is common for apartments to undergo repairs every 10 to 15 years. For owners, there is an increasing trend to change the appearance through color simulations during repairs to improve occupancy rates.

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

We handle many exterior wall renovations and large-scale repairs for condominiums and apartments in Miyamae Ward, Kawasaki City. We are happy to assist not only with large-scale repair work but also with partial repairs and leak repairs. “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 company’s own team. We are confident that we won’t be outdone in terms of cost, quality, and efficiency compared to other companies, so we welcome competitive estimates!

Large-scale repair work service area

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

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