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

Large-scale Renovations for Condominiums, Apartments, and Buildings in Minami Ward, Sagamihara City

Large-scale repair work that can be handled in Minami Ward, Sagamihara City

Large-scale repairs are not just “exterior wall painting” or “waterproofing,” but a comprehensive construction work that addresses the overall deterioration of the building while scaffolding is in place. At Kakeru Koumuten, we can handle all the following work in-house, ensuring clear responsibility and coordination of the process.

Scope of Major Repairs Determined from Building Diagnosis

It is not guaranteed that all of the above works will be performed. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten, we conduct a free on-site survey to confirm the items below, compile a deterioration diagnosis report with photos, and propose the scope of work.

Reasons Why Kakeru Koumuten is Chosen for Large-Scale Renovations in Minami Ward, Sagamihara City

The reason why we can be entrusted with large-scale repairs in Minami 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 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, allowing for swift responses in emergencies!

In-house Waste Sorting

Large-scale repairs 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 reductions 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 thermal insulation tests using thermal insulation testing equipment 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.

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

We can 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 on Staff

We have obtained permits for the construction industry and for the collection and transportation of industrial waste! We also have nationally certified sheet metal and painting skilled workers on staff, 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 manage asbestos-containing roofing materials and conduct preliminary surveys.

4. Warranty and Aftercare

Most large-scale repair works, including “painting work,” “substrate repair work,” and “waterproofing work,” come with a warranty!
Aftercare is available every year, and we send out notification DM each year.

5. Flexible and Prompt Response

Our company is equipped to handle various troubles and situations related to apartments and condominiums.

We can also address exterior walls and rooftops that cannot be checked from high places using drones! During leak investigations, we can utilize a thermal imaging camera, which helps in identifying 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. Staff Development

Our staff creates various models for skill enhancement and conducts practical training. Since different processing and techniques are required at the site, we regularly provide skill improvement education to ensure that each staff member can respond effectively. We also educate on points to be careful about and areas to check during large-scale repair work.

7. Consideration for Residents and Neighbors

During large-scale repair work, we not only notify residents and visit neighbors to greet and explain, but we also set up notice boards at 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

Each process will be inspected by a responsible person, and detailed construction photos will be taken. We use film thickness inspection equipment and check sheets to ensure that no inspections are overlooked. During exterior painting and waterproofing work, we check the number 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 photograph and report the used paint.

9. Exterior 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 making an image change, we hope to help enhance the stylish appearance and increase occupancy rates! Of course, it is also possible to arrange paint samples for actual color confirmation.

*In Minami Ward, there are areas where rules for community development, such as district plans, are established. Since the arrangements 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 conduct trial painting on your exterior wall. By doing 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 colors are also possible)
・Simulation for applying metal siding
・Simulation using accent materials such as cornices and louvers
・Simulation for roof painting and roof replacement work

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

Estimated Costs for Major Repairs in Minami Ward, Sagamihara City

The costs for major repairs vary significantly based 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, followed by our company’s estimates based on past projects categorized by size, and finally, examples of unit prices for specific jobs.

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. Note that this survey’s figures 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 do not total 100% due to rounding and non-responses.

Breakdown of Construction Costs (What the Money is Spent On)

Source: Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Renovation 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 not a criterion for judging the appropriateness of individual estimates.

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

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

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 painting,” “waterproofing,” and “miscellaneous expenses.” Before comparing total amounts, please check what each item includes, how much, and at what cost.

Examples of Unit Prices for Repair Work

*Costs and warranty periods vary depending on shape, quantity, substrate condition, and type of materials. 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 = correct” is not always true. The best way to choose is to align when the next major repair will be with the lifespan of the materials to avoid 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 due to location, sunlight, and airflow, so confirming the condition of each side through a 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 required 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 of Condominiums)

In the comprehensive survey for the fiscal year 2023, 36.6% of management associations responded that “the repair reserve fund is insufficient compared to the plan.” There are four main options if there is a shortfall.

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

Both Sagamihara City and Kanagawa Prefecture do not list subsidies specifically for large-scale renovation work in the publicly available list of grant programs. The available options can be broadly categorized into the following four types. The eligibility and application status of these programs may change during the fiscal year, so please be sure to check with our company or the respective offices 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 (such as exterior wall 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 by half (up to the equivalent of 100㎡ per unit). The reduction applies to the fiscal year with the assessment date of January 1 of the year following the completion of the work.

* The national leaflet shows the range of reduction percentages as a nationwide system. The reduction percentage in Sagamihara City is 50%. The application should be submitted to the city’s Asset Tax Division (Building Evaluation Group 1 & 2, Phone 042-769-8224).

② Support and Subsidies for Condominium Management in Sagamihara City (Management Associations should start here)

The support related to condominiums in Sagamihara City is handled by the city’s Housing Division (Phone 042-769-9817). It focuses not on subsidies for the construction costs of large-scale repairs, but on consultations, planning, and purpose-specific support such as seismic resistance and EV charging.

Source: Sagamihara City “Plans and Policies Regarding Condominiums” / Same “Condominium Advisor Dispatch System” / Same “Support for Earthquake Countermeasures for Condominiums Built to Old Seismic Standards” / Same “Subsidy for Electric Vehicle Charging Equipment Installation”

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

This is a system certified by Sagamihara City. Upon receiving certification, there are interest rate benefits for the “Condominium Common Area Renovation Loan” from the Japan Housing Finance Agency and Flat 35 (Maintenance Preservation Type), which also relates to one of the requirements for the Long Lifespan Promotion Tax System (certification alone does not guarantee tax reduction). The main criteria include holding a general meeting at least once a year, maintaining management regulations, separate accounting for management fees and repair reserve funds, overdue amounts of more than three months being 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 over 30 years.” Additionally, Sagamihara City requires initiatives for disaster prevention (such as creating disaster prevention plans, organizing voluntary disaster prevention groups, stockpiling disaster prevention supplies, and conducting disaster prevention training).

*The application fee for certification to the city is 3,600 yen if there is one long-term repair plan. Prior consultation with the Housing Division and pre-confirmation with the (Public Interest Incorporated Foundation) Condominium Management Center (online) is required before applying.

④ National Energy Saving Support | Housing Energy Saving 2026 Campaign

Changes for FY 2026The “Child-Rearing Green Housing Support Project” for FY 2025 has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in FY 2027 and will not be implemented in FY 2028. Please be careful not to establish funding 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 apply to common areas of rental apartments or units not occupied by the owner.

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 Minami Ward, Sagamihara City

Minami Ward, Sagamihara City is located in the southern part of Sagamihara City, with a total area of 38.1 km², accounting for 11.6% of the city area, and the largest population among the three wards in the city. The area around Sagami-Ono Station is a representative commercial and business district of the city, while the central part of the ward features green spaces such as Komorebi no Mori, the southwestern part has rural areas along the Sagami River, and the industrial park is located in Asamizodai. The urban area along the Odakyu Line also includes U.S. military facilities (Camp Zama and Sagamihara Housing Area). Due to the presence of urban areas, residential areas, large-scale apartment complexes, and industrial and agricultural land within the same ward, the way buildings deteriorate and the method of scaffolding vary depending on the location.

Source: Sagami Hara City “Population and Number of Households in Minami Ward” as of September 1, Reiwa 8 (based on the preliminary figures of the 2027 national census)／Same “Profile of Minami Ward”／Same “Urban Planning Master Plan for Minami Ward”

Buildings in Minami Ward are divided into “four types”

In Minami Ward, the development of the town varies by location, so not only the age of the buildings but also the location of the buildings (urban areas around the station, residential areas along the Odakyu Line and National Route 16, large-scale apartment complexes and housing estates, and the industrial and agricultural areas in the western part such as Asamizodai) will affect the scale of major repairs needed in the next renovation. Please check which type your building falls under.

Source: Sagamihara City “Profile of Minami Ward” / Same “Minami Ward Vision” (August 2012) / Same “Urban Planning Master Plan for Minami Ward”

Four Unique Factors in Minami Ward that Damage Buildings

From the publicly available materials of Sagamihara City, we have narrowed down four characteristics of Minami Ward that are linked to large-scale repairs.

Source: Sagamihara City “Minami Ward Vision” (August 2012) / Same “Urban Planning Master Plan for Minami Ward”

Key Points to Consider When Proceeding with Construction in Minami Ward

* Kakeru Koumuten Co., Ltd. has five bases in Yokohama City and serves the entire Minami Ward, including Sagami-Ono, Odakyu-Sagamihara, Furuuchi, Higashi-Rinkan, Asamizodai, and Sobudai.

Signs of Deterioration and Timing for Major Repairs

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

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

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

Source: Ministry of Land, Infrastructure, Transport and Tourism “Guidelines for Creating Long-term Repair Plans” (Reiwa 6, June revision, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “Survey on the Actual Conditions of Large-scale Repair Work for Condominiums in FY2021”

Examples of Large-scale Renovation Work

This is an example of exterior renovation work on a mixed-use building undertaken by Kakeru Koumuten Co., Ltd. The building had leaks occurring in several places, and we combined clear waterproofing for the tile exterior walls with waterproofing for the roof for the renovation.

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

Customer Feedback

Flow from On-site Investigation to Completion of Construction

From inquiry to completion of construction and aftercare, one representative will consistently handle your case. In the case of management associations, a resolution at the general meeting is 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 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 waterproof layers, and if necessary, investigate the roof, high places, and leak areas using drones or thermal imaging. For properties in Minami Ward, we will check whether they are located near the station or along main roads or in residential areas, the distance to neighboring properties, the width of the road and delivery routes, pedestrian flow, drainage, rust on metal parts and fittings, and parking lots.
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. Multiple plans can also be proposed.
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 install a bulletin board at the entrance (with a construction schedule and laundry information). If temporary relocation of parking is necessary, adjustments will be made at this stage.
6. Installation of Temporary Scaffolding & Various Works Our in-house scaffolding team will set up the scaffolding, followed by high-pressure washing, substrate repair, sealing, exterior wall painting, tile repair, waterproofing, and work on metal parts and accessories in that order. A responsible person will inspect each process and take construction photos.
7. Completion Inspection, Scaffolding Dismantling & Handover We will confirm the finish in the presence of the customer and provide construction photos, a report on the 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, Approval for Additional Work, 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.

What Will Life Be Like During Construction? Impact on Residents

Large-scale repairs are generally 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 avoided 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 Minami Ward of Sagamihara 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 work with photos, it can offer 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, content of explanations, and management system.

Large-scale repair work involves not only the construction itself but also the potential for troubles with residents and nearby neighbors. 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 specializes in exterior work, so 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 construction, having a leak warranty from the contractor ensures that repairs can be made at no cost, providing peace of mind! Companies that offer warranty periods demonstrate confidence in their work, which can be a criterion for selecting a contractor.

Warranty periods vary by contractor and type of 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 there are warranties or aftercare services available.

Kakeru Koumuten sends out annual DM for aftercare maintenance, allowing for yearly inspections. We also provide simple repairs such as partial sealing at no charge.

Obtain estimates from multiple contractors (at least 3 companies)

When requesting large-scale repairs, be sure to obtain estimates from multiple contractors. It is important to get estimates from at least 3 companies and compare their estimates and reports! Even for the same work, costs can vary by contractor, 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 processes” in detail! Costs can be lowered by using lower-grade materials or skipping processes, so avoid making decisions based solely on price. Especially since substrate repair work can be difficult to assess from appearance, ensure that the repair method is appropriate for the condition of the substrate!

Check these points in the estimate (checklist)

Check if it is managed in-house

Large-scale repair work includes various tasks such as “substrate repair,” “exterior wall painting,” “waterproofing work,” and “pipe replacement,” and the plan content 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 managing in-house with knowledge and experience, responsible construction at a reduced cost becomes possible.

Additionally, contractors that outsource to subcontractors may also have delayed responses in case of troubles during construction. It is safer to avoid having a company that has not directly consulted 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 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 concern. 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 to design consulting firms in the Kanto region (two design consulting firms were also subject to exclusion orders).

※This content is based on the announcement by the Japan Fair Trade Commission (September 28, 2026).

Three Typical Methods

Source: Ministry of Land, Infrastructure, Transport and Tourism “On the Proper Ordering of Large-Scale Repair Work for Condominiums” (Notification dated April 3, 2023, 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 meeting minutes to ensure transparency
• Confirm the reasons for unusually low consulting fees
• Include a penalty clause in the contract for cases of collusion
• Avoid concentrating information with a single consultant and verify specifications independently

Frequently Asked Questions about Large-Scale Renovations in Minami Ward, Sagamihara City

How much does a large-scale renovation in Minami Ward, Sagamihara 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 and roofing work is required, so we will provide an estimate through a free on-site survey.

How often should large-scale renovations be carried out?

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, floating 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. Older buildings tend to have a greater proportion of tile repairs and iron part replacements in the second and third renovations.

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

For apartments, it typically takes 3 weeks to 2 months, for small condominiums or buildings 1.5 to 3 months, and for condominiums with over 50 units about 4 to 6 months. Residents can remain in their homes during the construction. However, while scaffolding is in place, there may be restrictions on drying laundry outside and opening windows, so we take thorough measures to minimize the impact on daily life, such as distributing advance notices, providing updates on the schedule and laundry information on 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 1 to 1.5 years for the establishment of the repair committee, building diagnosis, contractor selection, and general meeting resolutions, followed by 3 to 6 months for construction. Overall, it is advisable to plan for about 2 years to proceed comfortably. If you are using subsidies or tax incentives, please also factor in the time required to obtain management plan certification (which requires prior confirmation and general meeting resolution).

Are there any subsidies available for large-scale renovations in Minami Ward, Sagamihara City?

Neither Sagamihara City nor Kanagawa Prefecture lists subsidies specifically for large-scale renovation work in the publicly available grant system. However, if it is a condominium, you can utilize a 50% reduction in fixed property tax under the “Condominium Longevity Promotion Tax System” if certain conditions are met. Additionally, Sagamihara City has a condominium advisor dispatch system (first consultation free), seismic support for condominiums built to old seismic standards, management plan certification system, and subsidies for the installation of electric vehicle charging facilities in multi-family housing parking lots. If the work includes windows and insulation, it may be eligible for “Advanced Window Renovation 2026” or “Mirai 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 and starting construction.

I heard that fixed property taxes can be reduced with large-scale renovations. 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 (such as being over 20 years old and having more than 10 units) carries out large-scale renovations that contribute to longevity (including exterior wall painting, floor waterproofing, and roof waterproofing), the fixed property tax for the residential portion can be reduced by half for up to 100 square meters per unit. This applies to work completed between April 1, 2023, and March 31, 2027, and a declaration must be made to the Sagamihara City Asset Tax Division (Building Evaluation Section) within three months of completion. For certified management plan condominiums, there are additional requirements such as raising the repair reserve fund, so it is recommended to start preparations more than a year in advance.

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

Yes, there are. The national “Child-Rearing Green Housing Support Project” has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Management associations and management association corporations can also become joint project participants, allowing for insulation renovations in common areas. Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in fiscal year 2025, and it will not be implemented in fiscal year 2026. The “Advanced Window Renovation 2026 Project” began accepting bulk applications for multi-family housing starting May 29, 2026 (the application process is handled by registered contractors). Please be careful not to base your financial plans on outdated information.

一般的には3社以上の相見積もりを取ることをお勧めします。複数の業者から見積もりを取得することで、価格やサービス内容の比較が容易になり、適正な価格を把握しやすくなります。また、各社の提案を比較することで、工事の質や信頼性についても判断材料を得ることができます。翔工務店では、相見積もりの取得をサポートし、最適な選択ができるようお手伝いします。

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

What is the difference if we have our own scaffolding?

In large-scale repair projects, temporary construction accounts for about 20% of the total cost (according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for Reiwa 3). By not outsourcing scaffolding work, we can easily control costs in this area, and our in-house scaffolding team can flexibly respond to sudden changes in the schedule or additional work. Kakeru Koumuten Co., Ltd. owns scaffolding materials for approximately 100 single-family homes and plans scaffolding on-site according to the site conditions.

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

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

Can I request just 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 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 such as asbestos work supervisors and building material surveyors who can conduct the legally required pre-surveys, as well as cover methods 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 accidents due to falling exterior wall tiles, structural deterioration due to corrosion of rebar, leaks, and a decrease in asset value. Furthermore, for buildings subject to regular reporting under Article 12 of the Building Standards Act, investigations through comprehensive probing are required under certain conditions, such as when more than 10 years have passed since completion or exterior wall renovations for tiled or mortar-finished walls. In the list of buildings subject to regular reporting in Sagamihara City, apartment buildings may also be included depending on conditions such as the number of floors and floor area, and mixed-use buildings including stores require individual confirmation (Sagamihara City Building Review Division Phone 042-769-8254). 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 to perform repairs on apartments every 10 to 15 years. For owners, there is an increasing trend to change the appearance with color simulations during repairs to improve occupancy rates.

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

Our company is based in Yokohama City and has handled many exterior wall renovations and large-scale repairs for condominiums and apartments in Minami Ward. We are happy to respond not only to large-scale repair work but also to partial repairs and leak repairs. In urgent cases such as leaks, emergency measures may be possible, so please feel free to consult us. “I want it to last long with one renovation” “I want to keep costs down as much as possible” “I want to improve insulation performance because the room is hot” We will propose optimal solutions for your specific requests and future repair plans.

From temporary scaffolding work to roofing and exterior wall painting, all work is performed by our own team. We are confident that we will not lose in terms of cost, quality, and scheduling compared to other companies, so we welcome multiple quotes!

Large-Scale Repair Work Service Area

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

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