Leave the repairs and renovations of condominiums and apartments in Zama City, Kanagawa Prefecture to Kakeru Koumuten Co., Ltd.!
Large-Scale Repairs for Condominiums, Apartments, and Buildings in Zama City
To owners, management associations, and management companies considering large-scale repairs for condominiums, apartments, and buildings in Zama City, Kanagawa Prefecture.
Kakeru Koumuten Co., Ltd. is an exterior repair company that handles everything from the installation of temporary scaffolding to substrate repairs, exterior wall painting, tile repairs, sealing, waterproofing for roofs and balconies, and roofing work, all managed and performed by our own team. In Zama City, we have undertaken numerous large-scale repairs and exterior renovations for apartments, condominiums, and commercial facilities.
- On-site surveys and estimates are completely free (we welcome competitive estimates)
- All management from temporary scaffolding to exterior and roofing work is handled in-house
- Our own scaffolding team can handle sites in Zama City with elevation differences and retaining walls due to hills and river terraces
- Consultations for partial repairs or emergency measures for leaks are also possible
- Cost Estimate / For condominiums, the cost per unit is approximately 750,000 to 1,500,000 yen (about 70% fall within this range according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for the fiscal year 2021, with the most common being 1,000,000 to 1,250,000 yen. This amount excludes consumption tax and common temporary costs). For wooden apartments, the estimate is 2,000,000 to 4,000,000 yen per building.
- Estimated Cycle / 12 to 15 years. However, the deciding factor is not the number of years but the condition of deterioration.
- Particularly Relevant in Zama City / Approximately 60% of condominiums in the city are over 30 years old (as of Reiwa 5, according to Zama City’s plan). The elevation differences and retaining walls of hills and river terraces, drain blockages from algae, moss, and fallen leaves around sloped green spaces, and the color standards of landscape planning. Different perspectives are needed compared to “salt damage measures” along the coast.
- Available Funds / There are no subsidies specifically for large-scale repairs in Zama City or Kanagawa Prefecture, but if requirements are met, one-third reduction in fixed asset tax (for work completed by the end of March in Reiwa 9), national subsidies if including windows and insulation, and public financing may be available.
- Tips for Success / At least three competitive estimates. Compare not just the amounts but also the quantities, methods, and materials.
Large-scale repair work that can be handled in Zama 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 process.
| Type of Work | Main Contents |
|---|---|
| Temporary Scaffolding Work | Installed by our own scaffolding team using our own scaffolding materials. We handle mesh sheets, protection, and fall prevention measures. |
| Substrate Repair Work | Crack repairs, injection of floating mortar and tiles, explosion (exposed rebar) repairs, resin mortar repairs for missing parts. |
| Exterior Wall Painting Work | High-pressure washing, three coats from primer to topcoat, painting of ancillary parts (iron parts, gutters, water cut-offs, etc.). We accommodate radical control type, fluorine, and inorganic paints. |
| Tile Repair Work | Replacement of broken tiles, joint repairs, clear waterproofing of tile surfaces (such as Seven S). |
| Sealing Work | Replacement and additional sealing around sashes and exterior wall joints. |
| Waterproofing Work | Urethane waterproofing for rooftops, roof balconies, shared corridors, and stairs, PVC sheet waterproofing, and long sheet installation. |
| Roof Work | Roof painting, roof overlay (cover method), re-roofing, and ridge metal replacement. We have sheet metal craftsmen who can handle large roofs such as factories. |
| Iron and Metal Work | Painting of steel staircases, handrails, and PS doors, replacement of caps and water cut-offs. |
| Drainage and Wastewater Work | Cleaning and renovation of roof drains (insertion of renovation drains), resolving gutter blockages. This work is especially important in locations with sloped greenery and many trees. |
| Others | Replacement of rain gutters, rooftop and exterior wall inspections using drones, leak investigations using thermography, and preliminary investigations of asbestos-containing materials. |
Scope of Major Repairs Determined from Building Diagnosis
It is not always necessary to carry out all of the above works. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten, we conduct a free on-site survey to confirm the items below and compile them into a deterioration diagnosis report with photos, after which we will propose the scope of work.
| Diagnosis Area | Main Inspection Method | Scope of Work Determined by Diagnosis Results |
|---|---|---|
| Exterior Wall (Painted Surface) | Visual confirmation, checking the width of cracks and the condition of the paint film | Method and quantity of crack repairs, specifications for painting (whether to repaint or paint after removing the existing paint film) |
| Exterior Wall (Tile Surface) | Tap testing. High areas checked with a drone | Scope and estimated quantity for injection and replacement, whether clear waterproofing is necessary |
| Sealing | Checking for cracks, shrinkage, peeling, and hardening | Whether to replace or add to the existing seal, scope of joints to be worked on |
| Rooftop, Balcony, Shared Corridor | Checking for blisters or breaks in the waterproof layer, puddles, and the condition of drains | Full renovation or partial repair, method (urethane waterproofing, PVC sheet waterproofing, long sheet), whether drain renovation is necessary |
| Leak Areas | Thermal imaging camera, inspection with a drone | Identification of the cause and the priority areas for repair |
| Metal Parts, Roof, Accessories | Checking for rust, corrosion, lifting, and cracking | Whether painting is sufficient or if material replacement or overlay installation is necessary |
| Site and Surroundings | Checking retaining walls, slopes, trees, access routes, and parking | Planning for scaffolding and the scope of temporary construction |
Reasons Kakeru Koumuten is Chosen for Large-Scale Renovations in Zama City
The reason why we can be entrusted with large-scale repairs in Zama City is partly because “Kakeru Koumuten has a base in Kanagawa Prefecture”, but also due to “our unique approach to large-scale repair work that cannot be imitated by other companies”, which has 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 reduce scaffolding costs and provide quick and flexible responses.
We have approximately enough scaffolding materials for 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 purchase materials at a lower cost! Additionally, we always have stock available, allowing us to respond quickly in emergencies!
In-house Waste Separation
During large-scale repairs, various waste materials such as leftover paint, metal, and wood are generated. At Kakeru Koumuten, we sort and recycle waste materials in-house, leading to cost reductions in waste disposal.
Showroom Dedicated to Exterior Renovations

In the showroom, you can not only have meetings but also check actual samples and colors of exterior materials. Color simulations for exterior wall painting and heat insulation tests using a heat insulation testing machine are also available!
2. Cost Reduction through In-House Management and Construction
One of Kakeru Koumuten’s major strengths is in-house management and construction.
From inquiry to project completion, everything is managed by Kakeru Koumuten in a consistent system, allowing for high-quality large-scale repairs at reduced costs. Additionally, one representative will handle everything from the estimate to project completion. Since the responsible person does not change, communication can proceed smoothly.
We can fully handle everything from temporary scaffolding installation to exterior wall painting, substrate repair, 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. Obtaining Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation! We also have nationally certified sheet metal and painting technicians on staff, giving us confidence in our construction techniques. We can also handle large-scale roofing work for factories! Qualified personnel for asbestos work supervisors and building material asbestos surveys are also on staff, allowing us to handle asbestos-containing roofing materials and conduct preliminary surveys.
4. Warranty and Aftercare

Most large-scale repair works come with a warranty for services such as “painting work,” “substrate repair work,” and “waterproofing work”!
Aftercare maintenance is available every year, and we send out notification DM annually.
5. Flexible and Prompt Response
Our company is equipped to handle various troubles and situations related to apartments and condominiums.
We can also address exterior walls and rooftops that cannot be checked from high places using drones! During leak investigations, we can use a thermal imaging camera to help identify the cause of leaks!
We will respond according to your wishes. We also accept emergency measures for sudden leaks! We will promptly respond to urgent requests or emergencies!
6. Staff Development
Our staff create various models for skill improvement and conduct practical training. Since different sites require various processing and techniques, we regularly provide skill enhancement education to ensure each staff member can respond appropriately. We also educate on points to be careful about and areas to check in each stage of large-scale repair work.
7. Consideration for Residents and Neighbors

During large-scale renovation work, we will not only notify residents and greet nearby residents, but also install a bulletin board at the entrance to display the construction schedule and notices! Additionally, we will thoroughly educate visitors on proper manners to minimize any inconvenience to residents and neighbors.
8. Strict Quality Control

Each stage will undergo inspections by a responsible person, along with detailed photographs of the work. We use a film thickness inspection machine and check sheets to ensure that no inspections are overlooked. During exterior wall painting and waterproofing work, we will verify the quantity of used paint cans to ensure that the specified amount of paint is used, and we will prevent construction defects by ordering paint directly from our company. Of course, we will also take photos of the used paint and report them.
9. Exterior Wall Painting Color Simulation
9-1 Self Color Simulation

The simulations we create can be done using actual photos of your apartment or building!You can also simulate using your smartphone or computer. By simulating before 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 Zama City, the entire area is designated as a landscape planning zone, and there are districts where “designs that consider the surrounding landscape harmony” are required in district planning. Having a color simulation screen will make explanations at community association and management union general meetings proceed smoothly.
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 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 colors are 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 change! We hope that by renovating the appearance of your apartment or condominium, it will help increase the occupancy rate.
Estimated Costs for Major Repairs in Zama City
The costs for major repairs vary significantly based on the size of the building, deterioration status, scope of work, and materials used. First, please refer to the national average based on public statistics, then to our company’s estimates based on construction performance by scale, and finally to unit price examples for each project.
The national average for condominiums is 750,000 to 1,500,000 yen per unit
According to a survey conducted by the Ministry of Land, Infrastructure, Transport and Tourism, which compiled 818 construction cases (FY 2021), the construction costs for major repairs are concentrated at about 70% in the range of 750,000 to 1,500,000 yen per unit, with the most common price range being 1,000,000 to 1,250,000 yen. Please note that the amounts in this survey do not include consumption tax and common temporary construction costs, so the conditions differ from the current total construction costs including tax.
| Construction Cost per Unit | Percentage | Construction Cost per Unit | Percentage |
|---|---|---|---|
| Up to 750,000 JPY | 15.1% | 1,250,000 to 1,500,000 JPY | 17.4% |
| 750,000 to 1,000,000 JPY | 24.7% | 1,500,000 to 2,000,000 JPY | 9.1% |
| 1,000,000 to 1,250,000 JPY | 27.0% (most common) | Over 2,000,000 JPY | 2.8% |
Source: Ministry of Land, Infrastructure, Transport and Tourism “Survey on Large-Scale Renovation Work for Condominiums in FY2021” (200 companies, 818 cases) *Amounts do not include consumption tax or common temporary costs. Percentages may not total 100% due to rounding and non-responses.
Breakdown of Construction Costs (What the Money is Spent On)
| Category | Composition Ratio | Main Contents |
|---|---|---|
| Construction-related Work | 60.3% | About half for exterior walls, about one-third for waterproofing. Substrate repairs, tiles, painting, waterproofing |
| Temporary Works | 22.8% | Scaffolding, mesh sheets, protective coverings, etc. (does not include common temporary costs) |
| Miscellaneous Expenses | 10.3% | Site management fees, general management fees, statutory welfare expenses, etc. (9.5%), insurance premiums for large-scale renovation defect insurance (0.8%) |
Source: Ministry of Land, Infrastructure, Transport and Tourism “Survey on Large-Scale Renovation Work for Condominiums in FY2021” (Second aggregation of large-scale renovation work. Overall average is construction-related 59.0%, temporary works 22.3%, miscellaneous expenses 9.9%). *The total does not equal 100% because equipment-related work, exterior works, and others are included. This is an average value and not a criterion for judging the appropriateness of individual estimates.
Cost Estimates by Building Size (Scaffolding, Substrate Repairs, Exterior Wall Painting, Waterproofing, Sealing Set)
| Type and Scale of Building | Estimated Cost | Estimated Construction Period |
|---|---|---|
| Wooden Apartment (2 stories, 6-10 units) | 2,000,000 – 4,000,000 JPY | 3 – 5 weeks |
| Steel Frame/RC Apartment (3 stories, 10-20 units) | 4,000,000 – 9,000,000 JPY | 1 – 2 months |
| Mixed-use Building/Small-scale Condominium (4-5 stories) | 5,000,000 – 15,000,000 JPY | 1.5 – 3 months |
| Medium-scale Condominium (30-50 units) | 20,000,000 – 50,000,000 JPY | 3 – 5 months |
| Large-scale Condominium (100 units or more) | Around 100,000,000 JPY or more | 6 months or more |
*The above estimates are based on Kakeru Koumuten’s construction records and may vary depending on the presence of roofing work, steel work, plumbing, etc. For condominiums, please also consider the amount calculated by multiplying the national statistics (750,000 – 1,500,000 JPY per unit) by the number of units as a guideline.
Breakdown of Costs for Temporary Works, Substrate Repairs, Exterior Walls, and Waterproofing
The estimate for large-scale repairs is broadly divided into “Temporary Works,” “Substrate Repairs,” “Sealing,” “Exterior Painting,” “Waterproofing,” and “Miscellaneous Expenses.” Before comparing total amounts, please check what each item includes, how much, and at what cost.
| Item | What to Check in the Estimate |
|---|---|
| Building Prerequisites | Structure (Wooden, Steel Frame, RC), number of stories, number of units, exterior wall area, and waterproof area. Confirm whether the area is based on drawings or actual measurements. |
| Common Temporary Works and Scaffolding | Area and unit price of scaffolding, contents of mesh sheets, protection, temporary toilets, etc. According to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for Reiwa 3, temporary works such as scaffolding account for about 20% of construction costs (excluding common temporary costs). |
| Substrate Repairs | Quantities and unit prices for repair methods such as cracks, lifting, and spalling. Since these items are not confirmed until scaffolding is set up, please check whether the quantities are estimated or settled based on actual numbers, and the settlement method if quantities increase or decrease. |
| Sealing | Whether it is a replacement or additional sealing, length to be applied (m), material name. |
| Exterior Painting | Painting area (㎡), manufacturer name, product name, grade of paint, number of coats, and scope of ancillary parts. |
| Waterproofing | Area for each part such as rooftop, balcony, and shared corridor, construction method, material name, and whether drain renovations are included. |
| Inspection and Reporting | Whether inspections for each process, construction photos, and completion reports and warranty documents are included. |
| Miscellaneous Expenses | Contents and proportions of site management fees, general management fees, statutory welfare expenses, etc. According to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for Reiwa 3, these average about 10% of construction costs, but this varies depending on the scale and conditions of the building, so there is no uniform standard. |
| Tax Classification | Whether the amounts are tax-inclusive or tax-exclusive. Since companies may display this differently, make sure to align them before comparing total amounts. |
Examples of Unit Prices for Repair Work
| Repair Method | Materials Used | Cost |
|---|---|---|
| Tile Replacement | Existing Similar Tiles | per piece / 2,000 JPY〜4,000 JPY |
| Repair of Floating Tile and Mortar Areas | Epoxy Resin Injection | per square meter / 3,000 JPY〜5,000 JPY (Varies depending on the degree) |
| Tile Joint Mortar Repair | Mortar for Tile Joints | per square meter / 1,000 JPY〜2,000 JPY (Varies depending on the degree) |
| Repair of Concrete Spalling Areas | Rust Preventive for Rebar + Resin Mortar | per area / 1,000 JPY〜2,000 JPY (Varies depending on the degree) |
| Crack Repair | Filler or Polymer Cement | per meter / 100 JPY〜2,500 JPY (Varies depending on the degree) |
| Exterior Wall Painting (3 Coats) | Radical Control Silicone Paint | per square meter / 2,500 JPY〜3,500 JPY |
| Roof Top Urethane Waterproofing (Ventilated Buffer Method) | High Strength Urethane | per square meter / 6,500 JPY〜9,500 JPY |
| Sealant Replacement | Modified Silicone | per meter / 900 JPY〜1,500 JPY |
| Temporary Scaffolding | In-house Owned Scaffolding Materials (Wedge Type) | per square meter / 700 JPY〜1,000 JPY |
*Costs and warranty periods vary depending on shape, quantity, substrate condition, and type of materials. If you would like a detailed estimate, please feel free to contact us. Estimates are completely free.
Select Paint and Waterproofing Grades Based on “Years Until Next Repair”
“Good paint does not always equal the right choice.” Aligning when to conduct the next major repair with the durability of the materials is the most efficient way to choose.
| Grade | Estimated Lifespan | Suitable Cases |
|---|---|---|
| Silicone / Radical Control Type | 10-16 years | Buildings that are cycled every 12-15 years. A good balance of cost and performance. The lifespan varies by product, so choose a product specification that matches the cycle. |
| Fluorine | 16-20 years | Buildings that want to set the next repair after 15 years, high-rise or complex-shaped buildings where scaffolding costs are high. |
| Inorganic | 18-22 years | Buildings that want to suppress dirt adhesion. Also effective for surfaces surrounded by trees or sloped green areas where moss and algae need to be controlled. |
| Urethane Waterproofing (Rooftop) | 8-15 years | Rooftops with complex shapes, when wanting to renovate while utilizing the existing waterproof layer. Mid-term inspections and repairs, such as re-coating the top coat, are prerequisites. |
| Vinyl Sheet Waterproofing | 20-25 years | Rooftops with large areas and simple shapes. The construction period is short. |
| Asphalt Waterproofing | 15-20 years | Rooftops planned for long cycles. The cost per instance will increase. |
* The estimated lifespan is a general guideline and may vary depending on sunlight, location, and substrate condition. For shaded and humid surfaces, choosing paints with anti-algae and anti-mold properties can change durability.
Guidelines for Repair Reserve Funds and Options When Insufficient
According to the Ministry of Land, Infrastructure, Transport and Tourism guidelines, the standard for repair reserve funds is indicated as a monthly amount per exclusive area. Additional charges are necessary if there is a mechanical parking lot.
| Building Size (Less than 20 Stories) | Monthly Estimate (Average) | Range Covering Two-Thirds of Cases | Conversion for 70㎡ |
|---|---|---|---|
| Building Total Floor Area Less than 5,000㎡ | 335 JPY/㎡ | 235-430 JPY/㎡ | Approximately 16,500-30,100 JPY |
| 5,000-10,000㎡ | 252 JPY/㎡ | 170-320 JPY/㎡ | Approximately 11,900-22,400 JPY |
| 10,000-20,000㎡ | 271 JPY/㎡ | 200-330 JPY/㎡ | Approximately 14,000-23,100 JPY |
| Over 20,000㎡ | 255 JPY/㎡ | 190-325 JPY/㎡ | Approximately 13,300-22,750 JPY |
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 Reiwa 5 Fiscal Year Comprehensive Survey of Condominiums, 36.6% of management associations responded that “the repair reserve fund is insufficient compared to the plan.” There are four main options when funds are insufficient.
| Options | Considerations and Points of Caution |
|---|---|
| ① Adjusting the Construction Schedule | Based on the deterioration diagnosis, postpone less urgent construction to the next time. However, it is essential to distinguish between construction that can be postponed and that which cannot, as delaying waterproofing and tile fall prevention measures can ultimately be more costly. |
| ② Reviewing the Scope and Specifications of Work | Reassessing the paint grade, changing from full renovation to partial renovation, etc. Please consider this separately from “apparent cost reductions” that skip processes. |
| ③ Utilizing Subsidies and Tax Systems | Subsidies for energy-saving renovations, etc. (to be discussed later). The reduction of fixed asset tax is a system that lowers the tax amount for each unit owner, and does not directly increase the repair funds of the management association. |
| ④ Increasing Reserve Funds, Borrowing, and One-Time Payments | In addition to considering an increase in repair reserve funds at the general meeting, the Housing Finance Agency’s condominium common area renovation loans require no collateral. Interest rates can be lowered by obtaining management plan certification. |
Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Zama City
In Zama City, Kanagawa Prefecture, there are no subsidies specifically for large-scale renovation work. The available options can be broadly categorized into four types. The eligibility and application status of these systems may change during the fiscal year, so please be sure to confirm with our company or the respective offices before contracting or starting work. (As of October 8, 2026)
| Type | Details |
|---|---|
| ① Support for Investigation and Consultation | Subsidies for seismic diagnosis costs and free dispatch of experts (advisors) to management associations. Can be used in the preliminary stage before large-scale repairs. |
| ② Construction Subsidies by Purpose | Energy-saving (windows, insulation), solar power, storage batteries, etc. Used as part of large-scale repairs. |
| ③ Tax Incentives | Reduction of property tax under the condominium longevity promotion tax system. |
| ④ Public Financing | Housing Finance Support Organization’s financing for condominium common area renovations. |
① Condominium Longevity Promotion Tax System (Property Tax Reduction)
If large-scale repairs (including exterior painting, floor waterproofing, and roof waterproofing) that contribute to longevity are performed on condominiums that meet certain requirements, the property tax amount for the following year will be reduced. The reduction rate is determined by the municipality’s ordinance under the “local special exception,” and Zama City reduces the property tax amount by one-third (up to the equivalent of 100㎡ per unit; urban planning tax is not included).
| Main Requirements | Built for over 20 years; total number of units is 10 or more; at least one instance of exterior painting, floor waterproofing, and roof waterproofing has been completed; meets one of the following: ① A management plan certified condominium that raised the amount of repair reserve fund (average amount during the planning period) from below the standard to above the standard after September 1, 2021 ② A management association that received advice and guidance from the city, resulting in a long-term repair plan that meets the standards (advice and guidance are not available upon request). |
|---|---|
| Construction Implementation Deadline | From April 1, 2023, to March 31, 2027. |
| Declaration | Within three months after the completion of construction (as stipulated by national regulations), submit the “Special Exception Application Form” to Zama City Property Tax Division, Building Section (Phone: 046-252-8047). A large-scale repair construction certificate issued by an architect, etc., is required. |
| Notes | The reduction can only be applied once for the same condominium. Simply obtaining management plan certification does not make it eligible; there are requirements such as raising the repair reserve fund. A review of the long-term repair plan is also necessary, so it is recommended to prepare at least one year before construction. |
The contact point for condominium-related matters in Zama City is the Urban Development Division, Guidance Section (Phone: 046-252-7396) at the city hall. Based on the “Zama City Condominium Management Optimization Promotion Plan” (Fiscal Year 2024 to Fiscal Year 2028), the city conducts the certification of management plans and provides information on the dispatch of condominium advisors from Kanagawa Prefecture. While it does not provide subsidies for the actual costs of large-scale repairs, it can be used as a basis for preliminary investigations and decision-making.
| System | Details |
|---|---|
| Condominium Earthquake Diagnosis Subsidy System | Applicable to condominiums that obtained construction confirmation and commenced construction before May 31, 1981, and received a completion inspection certificate (more than half of the total area must be common residential units, and more than half of the total number of units must be occupied by unit owners). A resolution to conduct an earthquake diagnosis must be made at the management association meeting. The subsidy covers up to 50% of the diagnosis cost (excluding tax), with a maximum of 1.5 million yen per case (for total area less than 1,000㎡, 1,500 yen per ㎡). ※If diagnosis begins before prior consultation, it will be excluded / Evaluation by the Earthquake Judgment Committee is required for the diagnosis results. |
| Housing Renovation Subsidy System | Applicable to residential properties within the city where the owner resides (exclusive parts of condominiums), large-scale repairs of common areas are not eligible. The subsidy amount is 50,000 yen. Applications for the fiscal year 2026 have already closed. |
Source: Zama City “Condominium Earthquake Diagnosis Subsidy System” / Zama City “Fiscal Year 2026 Housing Renovation Subsidy System” / Zama City “Formulation of the Condominium Management Optimization Promotion Plan” ※The information page for earthquake diagnosis subsidies was updated on March 20, 2023. Please check with the Urban Development Division, Guidance Section for the latest application status.
③ Management Plan Certification System (Entry for tax and interest rate benefits)
This is a system certified by Zama City, and upon certification, it meets one of the requirements for lower interest rates on the “Flat 35” loan from the Japan Housing Finance Agency and condominium common area renovation loans, as well as the longevity promotion tax system (certification alone does not guarantee tax reductions). The certification criteria are based on national standards, and there are no unique standards from Zama City. The main criteria include holding general meetings at least once a year, maintaining management regulations, separate accounting for management fees and repair reserve funds, ensuring that the amount of arrears is within 10% of the total, and “having a long-term repair plan that includes two or more large-scale repair works, created or reviewed within the last seven years, with a planning period of over 30 years.”
* Before applying, it is necessary to receive a preliminary confirmation through the management plan certification support service of the Public Interest Incorporated Foundation, Mansion Management Center (the usage fee is 10,000 yen per application). There is no certification fee when applying to Zama City. The validity period of the certification is 5 years (renewable).
④ National Energy Saving Support | Housing Energy Saving 2026 Campaign
Changes for 2026The “Child-rearing Green Housing Support Project” for 2025 has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Additionally, the “Long-term Excellent Housing Renovation Promotion Project” will end in Reiwa 7, and will not be implemented in Reiwa 8. Please be careful not to establish financial plans based on outdated information.
Mirai Eco Housing 2026 Project
| Target | Renovations of existing homes built before December 31, 2016, regardless of whether they are single-family or multi-family homes. Management associations and management association corporations can also become joint contractors (can be used for common area renovations). Rental housing is also eligible. |
|---|---|
| Required Work | A combination of insulation renovations for openings, structural (floor, wall, ceiling) insulation renovations, and installation of eco-friendly housing equipment is required. |
| Subsidy Limit | Depending on the age of the building and the energy-saving performance achieved, 400,000 to 1,000,000 yen per unit (1,000,000 yen if reaching the mandatory standards for houses built before 1991). |
| Period | Grant applications are generally made by registered contractors (construction contractors) after the completion of the work (the ordering party cannot apply themselves). Reservations for grant applications must be made by November 16, 2026, and grant applications must be submitted by December 31, 2026, at the latest (will end as soon as the budget limit is reached). |
Advanced Window Renovation 2026 Project
| Target | Installation of interior windows, replacement of exterior windows, glass replacement, etc., for existing residential buildings (single-family and multi-family), and renovation to high-performance thermal insulation windows. For multi-family buildings, subsidy unit prices are set separately for “low-rise” and “mid-to-high-rise” buildings. |
|---|---|
| Bulk Application for Multi-Family Buildings | From May 29, 2026, applications for “bulk subsidy applications for multi-family buildings (including reservations)” have begun. The application process is carried out by registered contractors (window renovation contractors), and the management association cannot apply on its own, but it allows for a consolidated application for all units, making it a good system for window and entrance door renovations in conjunction with large-scale repairs. |
| Subsidy Limit | For residential buildings, 1 million yen per unit (changed from 2 million yen in fiscal 2025). For non-residential buildings over 240 square meters, 10 million yen per building. |
| Period | Construction must start after November 28, 2025. The subsidy application must be made after the completion and handover of the work, with reservations accepted until November 16, 2026, and subsidy applications accepted until December 31, 2026, at the latest (ending as soon as the budget limit is reached). |
⑤ Kanagawa Prefecture Subsidies and Support (Subsidy applications for fiscal 2026 have ended)
| Subsidy for Existing Residential Energy Saving Renovation Costs | Applicable to residences (owned or jointly owned) where the applicant resides permanently in the prefecture (exclusive parts of condominiums). Renovation of windows (including entrance doors) that are exposed to the outside air is mandatory. The subsidy covers one-third of the eligible expenses, or a maximum of 150,000 yen, whichever is lower. The second phase for fiscal 2026 reached the budget limit on September 30, and applications were closed. Construction started before the notification of subsidy decision is not eligible, and applications by contractors on behalf of the owner are not permitted. |
|---|---|
| Subsidy for Residential Solar Power Generation and Storage Battery Installation Costs | Management associations of condominiums in the prefecture are also eligible. Solar power: 70,000 yen/kW, storage systems: 150,000 yen/unit. The second phase for fiscal 2026 reached the budget limit on the application start date of September 7, and applications were closed. If construction starts before the subsidy decision date, it is not eligible. This is a system to check if you are considering installing solar panels along with rooftop waterproofing. |
| Condominium Advisor Dispatch Project | The prefecture’s project dispatches advisors such as condominium management specialists and architects to management associations for free, providing advice on management and operation. This is applicable to management associations of condominiums in Kanagawa Prefecture (excluding Yokohama City, Kawasaki City, Sagamihara City, and Yokosuka City), and Zama City is also included. The application period for fiscal 2026 is until February 26, 2027 (may close early if there are many applicants). |
*The subsidy for existing residential energy saving renovation costs does not cover common areas of rental apartments or units not occupied by the owner.
⑥ Financing System (Housing Finance Agency Condominium Sumairu Loan)
If the management association borrows funds for large-scale repairs, it can utilize the Housing Finance Agency’s “Condominium Common Area Renovation Loan (Condominium Sumairu Loan).”
| Eligible Construction | Large-scale repairs, seismic retrofitting, flood prevention measures, energy-saving measures, balcony repairs, safety measures for elevators and parking lots, asbestos measures, costs for diagnosis and design by specialists |
|---|---|
| Collateral | No collateral required (joint guarantee by the condominium management center, etc.) |
| Repayment Period | Generally 1 to 10 years; 1 to 20 years for specific construction; up to 35 years for seismic, flood, and energy-saving construction after obtaining management plan certification |
| Interest Rate Reduction | ① Holding of Sumairu Bonds ② Obtaining management plan certification ③ Implementation of seismic, flood, and energy-saving construction, each reducing by 0.2% per year (up to 0.6% per year) |
| Main Requirements | Improvement of management regulations, resolution at the general meeting, the delinquency rate of repair reserve funds must be within 10%. Applications are accepted year-round |
Source: Housing Finance Agency “Condominium Sumairu Loan” (Official)
Cases Where Fire Insurance Can Be Used and Cases Where It Should Not Be Used
Damage caused by “accidental incidents” such as flying waterproof sheets, caps, and fences due to typhoons or strong winds, hail damage, and lightning strikes may be covered by fire insurance. It is important to separate and record damage caused by accidents from normal wear and tear during deterioration diagnosis.
On the other hand, normal wear and tear itself is not covered. There have been many incidents nationwide where companies entice customers by saying, “You can repair without any out-of-pocket costs with insurance,” and the National Consumer Affairs Center has repeatedly issued warnings. False claims can lead to insurance fraud charges. Please confirm the eligibility of your claim directly with your management association or owner with the insurance company or agent. Kakeru Koumuten Co., Ltd. will not provide such guidance.
Building Conditions and Repair Points in Zama City
Zama City is a town that established its city system in 1971 (Showa 46). According to the city’s landscape plan, it is located approximately 40 km from central Tokyo and about 20 km from central Yokohama. The rapid urbanization occurred during the high-growth period of the 1960s and 1970s due to the expansion of factories and population concentration in the metropolitan area. The city’s condominium management improvement plan indicates that the number of condominiums in the city sharply increased from the late 1980s to the late 1990s, with about 7 to 19 buildings constructed each year. Consequently, there is a characteristic that “collective housing built in the same period reaches the repair period at the same time.”
(As of September 1, Reiwa 8)
(As of September 1, Reiwa 8)
(6 units or more, as of Reiwa 5)
(167 buildings, as of Reiwa 5)
(Elevation 88.74m to 24.29m)
Source: Zama City Website (Population and Number of Households)/Zama City Condominium Management Improvement Plan (April, Reiwa 6)/Zama City Statistical Handbook (Land and Weather) ※The condominiums counted are those with 6 or more units.
Zama City’s Collective Housing is Divided into “Four Generations”
The number of condominiums in Zama City is organized by construction period according to the city’s plan. The type of major repairs that will be required next will vary depending on which generation your building falls into.
| Construction Period | Areas Frequently Mentioned in City Plans | Age of Building (as of 2026) | Major Repairs in Next Renovation |
|---|---|---|---|
| Before 1983 Most buildings are from this generation (49 buildings) |
Sagamigaoka/Soubudai (before 1973), Sagamigaoka/Iriya East (until 1983) | Over 43 years old | 3rd and 4th repairs. Replacement of water supply and drainage pipes, replacement of steel staircases and handrails, seismic diagnosis for old seismic standards (before May 1981) will be key points. |
| 1984–1993 The generation with the most buildings in the city (118 buildings) |
Areas around major stations and the eastern district (Komatsubara/Hibarigaoka) | 33–42 years old | 2nd and 3rd repairs. Measures against tile lifting and peeling, complete renovation of rooftop waterproofing, and renovation of sashes and entrance doors will become more significant. |
| 1994–2003 Heisei period subdivision (78 buildings) |
Areas around major stations and the eastern district (Komatsubara/Hibarigaoka) | 23–32 years old | 1st and 2nd repairs. Replacement of long sheet flooring in common corridors, waterproofing renovations, and resealing will be the focus. |
| After 2004 Relatively new generation (33 buildings) |
Higher proportion of Sagamigaoka/Soubudai | 22 years old or younger | 1st repair. Resealing and exterior wall painting will be the main tasks. |
Four Key Factors to Consider for Major Repairs Unique to Zama City
Instead of lumping together “salt damage measures because it’s Kanagawa Prefecture,” we have organized four factors to keep in mind for major repairs based on the topography and city rules of Zama City. Since circumstances vary for each building, individual confirmation will be made through on-site surveys.
① Elevation Differences of Hills and River Terraces, and Retaining Walls
The topography of Zama City is divided by the Zama Hills, which runs north-south through the center, with the Sagamino Plateau in the east and the Sagami River’s river terraces and alluvial lowlands in the west. The highest elevation in the city is 88.74m (Sagamigaoka 2-chome), and the lowest is 24.29m (near the Sagami River floodplain), resulting in an elevation difference of about 64m. For sites built on slopes, terraces, and retaining walls, the foundation for scaffolding and the route for material delivery differ from flat land. The district plan for the Midorigaoka area mentions the preservation of the stone retaining walls established through land readjustment projects as a landscape policy. It is reassuring to check not only the building itself but also the condition of retaining walls and slopes simultaneously.
② Sloped Green Spaces, Garden Trees, and Algae, Moss, and Fallen Leaves
The city’s landscape plan highlights the riverbank terraces, hillside green spaces, estate forests, spring water, and hedges as unique landscape resources of Zama. On the north-facing exterior walls and shared corridor floors, where sunlight is less accessible due to trees and slopes, algae, moss, and dark stains can easily appear. Clogging of roof drains and gutters due to fallen leaves can trigger puddles and leaks on the roof. We recommend thoroughly performing high-pressure washing, selecting paints with anti-algae and anti-mold properties, and conducting inspections and cleaning of drains, incorporating renovations as necessary into the work items.
③ Waterfronts and Lowlands of the Sagami River, Mekujiri River, and Hato River
Zama City is bordered by the Sagami River on the west and the Mekujiri River flowing through the center. The city’s disaster prevention hazard map indicates flood risk areas for the Sagami River and Hato River, as well as landslide warning areas. A hazard map for internal water (flooding from rainwater) is also available. During large-scale repairs, it is advisable to check which risk area your building falls into on the hazard map and to include inspections of waterproofing and drainage around the first floor, as well as the condition of drains and drainage systems.
④ Considerations for Color and Design Based on Landscape and District Plans
Zama City is a landscape administrative organization, and the entire city is designated as a landscape planning area. Repairs that change the appearance of buildings exceeding 15m in height or 1,000㎡ in building area, where the area of the repaired section exceeds 1,000㎡ or more than half of the total visible area, require notification. The base color of exterior walls is subject to color standards (for hues R, YR, and Y, saturation must be 6 or lower; for others, saturation must be 3 or lower, excluding accent colors that are less than one-fifth of the visible area). In the Suzuka and Nagayado specific landscape planning areas, repairs that change the appearance of buildings exceeding 10㎡ in floor area also require notification. Additionally, there are eight district plans within the city, and some districts focus on qualitative regulations rather than numerical standards, such as ensuring that the design of roofs and exterior walls is “considerate of the surrounding landscape harmony.” Sharing completion images through color simulations can facilitate consensus-building among neighbors, community associations, and management unions.
Source: Zama City Landscape Plan (Reiwa 1st Year, November Revision) / Zama City “Urban Planning Overview” (District Plan) / Zama City Disaster Prevention Hazard Map / Zama City Statistical Overview (Land)
Points of Discussion When Advancing Construction in Zama City
| Issue | Current Situation in Zama City and Kakeru Koumuten’s Response |
|---|---|
| Parking During Construction | Vehicles on the side where scaffolding will be erected need to be temporarily moved. In buildings without sufficient parking space on the premises, it may take time to secure an alternative location. We will coordinate with you regarding nearby coin parking and monthly rental availability starting 2 to 3 months before construction begins. |
| Material Delivery and Scaffolding | The urban area formed during the period of rapid economic growth has narrow roads and block shapes that remain unchanged, which is also a challenge noted in the city’s landscape plan. Combined with sloped or terraced sites, there are locations where large vehicles cannot access. Our own scaffolding team will assess the site and plan the delivery route and scaffolding layout. We will confirm parts that are likely to lead to increased costs after the estimate during the estimation phase. |
| Protection and Pruning of Plants and Hedges | Some areas in Zama City’s district plan have regulations that require hedges facing the road and policies for planting strips and greening within the premises (such as the Midorigaoka area and Higashihara 4-chome Higashihara Housing Area). If plants are removed or cut down for scaffolding, it may violate these regulations, so we will check the applicable regulations for that building and include pruning, transplanting, and restoration in our construction specifications. |
| Consideration for Neighbors | About 70% (73.1%) of the land use in Zama City is residential, and many locations are close to homes, making it easier for high-pressure washing debris and paint odors to reach neighbors. We recommend prior explanations through neighborhood associations or management organizations, and we are committed to greeting neighbors, posting work schedules, and adhering to working hours. |
| Time at Home | The time spent at home varies by building and household. Requests for clearing balconies and confirming presence will be communicated after checking your availability in advance. |
*Kakeru Koumuten has established five bases centered around Yokohama City and will visit areas within Zama City such as Sagamigaoka, Sobudai, Hibarioka, Iritani, Kurihara, and Midorigaoka.
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% of cases 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 symptoms like those listed below, we recommend an early on-site inspection.
| Part | Signs of Deterioration That Are Dangerous If Left Unattended | Main Countermeasures |
|---|---|---|
| Exterior Wall (Painted Surface) | Chalking (white powder on hands), fading, cracks wider than 0.3mm, blistering or peeling of the paint film | Substrate repair + exterior wall painting |
| Exterior Wall (Tile Surface) | Tile lifting or falling off, chipping of joints, efflorescence, hollow sounds when tapped | Injection for lifting, replacement, clear waterproofing |
| Sealing | Cracks in joints, shrinkage, peeling, hardening | Re-sealing |
| Rooftop/Balcony | Bloating or breaking of the waterproof layer, puddles, clogged drains, rain leaks to lower floors | Urethane waterproofing, sheet waterproofing, drain renovation |
| Metal Parts/Steel Stairs | Rust, peeling paint, corrosion of treads | Grinding + rust prevention + painting, component replacement |
| Roof | Lifting of ridge cap, cracking or warping of slate, moss, shifting of tiles | Roof painting, roof overlay (cover method), re-roofing |
| Concrete | Spalling (exposed rebar with rust stains), water leakage from cracks | Spalling repair + resin mortar filling |
| Shared Corridor/Stair Floor | Lifting or peeling of long sheet, opening at edges, exposure of substrate | Replacement of long sheet + substrate waterproofing |
Estimated Repair Cycles by Part (Ministry of Land, Infrastructure, Transport and Tourism Guidelines)
| Part/Work | Estimated Cycle | Part/Work | Estimated Cycle |
|---|---|---|---|
| Exterior Wall Painting (Repainting) | 12-15 years | Re-sealing | 12-15 years |
| Exterior Wall Painting (Existing Removal + Painting) | 24-30 years | Metal Parts Painting | 5-7 years |
| Rooftop Waterproofing (Repair/Renovation) | 12-15 years | Water Supply Pipe (Rehabilitation/Replacement) | 19-23 years/30-40 years |
| Rooftop Waterproofing (Removal/New Installation) | 24-30 years | Drain Pipe (Rehabilitation/Replacement) | 19-23 years/30-40 years |
*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 “Guidelines for Creating Long-Term Repair Plans” (Revised June 2024, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “Survey on 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. The building had leaks occurring from several locations, 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)
| Construction Details | Partial replacement of damaged tiles / Painting of auxiliary parts (pipes, water cut) / Rooftop waterproofing work (urethane waterproofing) / Exterior wall tile waterproofing (Seven S) / Sealing work around sashes / Repair of exterior wall tile mortar joints / Removal of ivy |
|---|---|
| New Materials Used | Exterior wall tiles: Kunishiro tiles / Painting of auxiliary parts: Radical silicone paint / Rooftop waterproofing: High-strength urethane (Sarasene A) / Exterior wall tile waterproofing: Seven S |
| Price Range | 4,000,000 – 4,100,000 JPY |
| Construction Period | 45 days |
| Location | Not disclosed |
| Background to the Construction | Due to leaks occurring from several areas such as the exterior walls and rooftop, we proposed waterproofing for the entire exterior wall. Seven S is a clear waterproofing material for tile exteriors, and while the cost is somewhat high, its waterproofing performance is excellent, making it recommended for cases where leaks are occurring from multiple areas of the exterior wall. |
Customer Feedback
Flow from On-Site Investigation to Completion of Construction
From inquiry to completion of construction and aftercare, one representative will consistently handle your case. In the case of management associations, a resolution at the general meeting is necessary, so starting the process 1 to 1.5 years before the desired start date will allow for a smoother progression.
- Contact Us (Free) Please reach out via phone, form, or LINE. If you have estimates from other companies, just presenting them is fine.
- 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 Zama City, we will also check the condition of retaining walls, slopes, trees, and access routes and parking.
- 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 plan proposals are also possible.
- 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 landscape planning notifications or district planning, we will also explain the color considerations.
- Notification to Residents & Neighbors We will distribute construction notices, 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.
- Installation of Temporary Scaffolding & Various Works Our own scaffolding 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 supervisor will inspect each process and take construction photos.
- Completion Inspection, Scaffolding Dismantling & Handover We will confirm the finish in the presence of the customer and provide construction photos, a report on the paint used, and a warranty certificate.
- Aftercare Maintenance We will send out annual DM notifications, and inspections can be conducted every year. Simple repairs such as partial sealing are provided free of charge.
Resident Communication, 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 provide materials and reports in the following four situations.
| Situation | Materials Provided / Actions Taken |
|---|---|
| Before Construction Building Diagnosis |
We will provide a deterioration diagnosis report with photos. This document summarizes the deteriorated areas and the basis for the proposed scope of work. |
| Before Construction to During Construction Notification to Residents & Neighbors |
We will distribute construction notices, visit neighbors to greet them, and provide information on the schedule and laundry via the entrance bulletin board. |
| During Construction Approval for Additional Work |
For deterioration discovered after scaffolding is set up, we will present photos, quantities, and costs, and proceed with construction after obtaining approval. |
| During Construction to Completion Inspection Report |
A supervisor will inspect each process and take construction photos. Upon completion, we will confirm the finish in the presence of the customer and provide construction photos, a report on the paint used, and a warranty certificate. |
* 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
For large-scale repairs, the principle is to proceed while you continue to live in the property. However, there will be some limitations on daily life while scaffolding is in place. Most troubles can be prevented by providing prior notice, so Kakeru Koumuten Co., Ltd. thoroughly explains and posts information before construction.
| Impacts | What to Expect / Our Response |
|---|---|
| Laundry | On days of high-pressure washing, painting, and waterproofing, outdoor drying will not be possible. We will inform you via bulletin boards and each household’s mailbox about “which side will be worked on today” and will ensure as many drying days as possible. |
| Window Operation | In addition to washing and painting days, there may be times when windows cannot be opened during other processes such as protection, drying, and waterproofing. We will inform you for each process, so please check the postings and notifications. We will organize the schedule to avoid continuous closures. |
| Balcony | During floor waterproofing and railing painting, we ask for temporary relocation of personal items, potted plants, and air conditioning outdoor units. The timing will be communicated in advance for each household. |
| Noise and Odor | The period of substrate repairs (breaking and drilling) will generate the most noise. Working hours are generally from 8 AM to 5 PM, and we will accommodate requests such as refraining from work on Sundays and holidays. Low-odor paint options are also available. |
| Security and Privacy | Scaffolding can become an entry point. We can take measures such as blocking sightlines with mesh sheets and installing locks and sensor lights on the scaffolding’s access stairs at night. We also thoroughly educate visitors on proper etiquette. |
| Parking | Vehicles on the side where scaffolding will be erected will need to be temporarily relocated. Since securing a relocation spot may take time, we will start securing a relocation spot together 2 to 3 months before construction begins. |
| Pets, Small Children, and Working from Home | If you have sensitivities to noise, please inform us in advance, and we may be able to adjust the work schedule accordingly. Please feel free to let us know. |
| Rented Rooms | We can assist owners in creating notification documents for tenants. If you are concerned about the impact of construction on occupancy rates, we can also propose an image change with color simulations. |
How to Choose a Large-Scale Repair Contractor and Ordering Methods
There are many large-scale repair contractors that cover Zama City, and you may be unsure which one to choose. When requesting renovations for apartments, condominiums, or buildings, please check the following four points.
● Have extensive experience in large-scale repairs
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (at least three)
● Confirm whether they manage their own work
Have Extensive Experience in Large-Scale Repairs
Large-scale repair contractors often have websites that showcase their exterior renovation project achievements. If they provide detailed explanations of repair contents with photos, it offers reassurance as a reference when you actually request their services.
Using Google and review sites to evaluate large-scale repair contractors can also be effective for comparison! Be cautious if there are many negative reviews. If there are few reviews, also check their project achievements, explanation content, and management system.
Large-scale repair work involves not only the construction itself but also the potential for troubles with residents and neighboring inhabitants. Therefore, it is necessary to post updates on 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 construction, and we receive many requests for exterior renovations of apartments and condominiums.
Check for Warranty and Aftercare Services
When choosing a large-scale repair company, let’s confirm the availability of warranties. If any issues such as leaks occur after the construction, having a leak warranty from the contractor ensures that repairs can be made at no cost, providing peace of mind! Companies that offer warranty periods are often confident in their work, making this a key criterion for selecting a contractor.
Warranty periods vary by contractor and the nature of the work, but typically range from 1 to 10 years. Emergency repairs or partial fixes often do not come with a leak warranty. Some contractors also provide aftercare services separate from warranties, so be sure to check for warranties and aftercare services.
Kakeru Koumuten Co., Ltd. sends out annual direct mail 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)
When requesting large-scale repairs, obtain estimates from multiple contractors. It is important to get estimates from at least three companies and compare their quotes and reports! Even for the same work, costs can vary between contractors, as well as warranties and aftercare services. Additionally, obtaining multiple estimates makes price negotiations easier.
When comparing estimates, consider not only the cost but also the “items in the estimate,” “methods and materials for substrate repairs and exterior wall painting,” and “confirmation of the process” in detail! If the quality of 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 is often not visible from the outside, it is essential to verify whether the repair method is appropriate for the condition of the substrate!
Check This on the Estimate (Checklist)
| Confirmation Items | Points to Check |
|---|---|
| Is there an excessive use of “one set” notation? | Are the quantities and unit prices clearly stated? With “Exterior Wall Repair One Set,” comparisons and verifications cannot be made. |
| Do the quantities match the actual measurements? | Are there quantities recorded that are far from the drawings or actual measurements? This is the area where inflation is most likely to occur. |
| Proportion of miscellaneous expenses | Details and proportions of site management costs, general management costs, statutory welfare costs, etc. According to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for the fiscal year 2021, the average is about 10% of the construction cost (excluding common temporary costs), but it varies depending on the size and conditions of the building, so there is no uniform standard. |
| Are the names of materials written down? | Are the manufacturer names, product names, grades, and number of coats for paints and waterproofing materials listed? |
| Treatment of quantities for substrate repairs | This is an item that cannot be accurately measured until scaffolding is set up. Is it stated whether it is “estimated quantity” or “actual quantity settlement,” and are there agreements for increases or decreases? This is the most important point. |
| Warranty and after-inspection | Warranty period for each construction, frequency of inspections, and scope of free support. |
| Company backing | Types of construction industry licenses, track record of similar scale and structure, presence of qualified personnel. |
Confirm 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.
If a contractor completely outsources to subcontractors, they may lack knowledge and experience, leading to proposals for repairs in irrelevant areas or meaningless work. If you investigate and then request a subcontractor, it may incur additional time and costs. By having knowledge and experience and managing in-house, responsible construction can be carried out at reduced costs.
Moreover, if a contractor is outsourcing completely, there is a risk that their response will be delayed 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 setup to exterior wall painting and waterproofing work in-house, with knowledgeable and experienced personnel managing the construction!
There are three ordering methods. The choice you make will change 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.
| Method | Procedure | Advantages | Disadvantages |
|---|---|---|---|
| Responsibility Construction Method | The construction company handles everything from investigation, design, construction, to management | No additional costs for commissioning design consultants (investigation and design costs may be included in the construction costs) / Single point of contact reduces the burden on the management association / Clear accountability / Can shorten the time until ordering | Specifications can easily be left to the construction company, making it difficult to compare side by side / Difficult to have third-party checks, requiring the management association to verify prices, specifications, and construction status |
| Design Supervision Method | A design office or consultant conducts the investigation and design, while a separate company handles the construction | Allows for comparison of construction companies under the same conditions / Independent supervision during construction | Consulting fees are required separately / Attention needed for risks of conflicts of interest and collusion / Tends to prolong the duration |
| Management Company General Contractor Method | The management company acts as the general contractor, with subcontractors performing the construction | Easy coordination with daily management / Minimal effort required from the management association | Tends to be more expensive due to intermediate margins / Competition principles may not be effective |
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 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 Schemes
① Dummy Estimates
Pre-determined companies are chosen to receive orders, while other companies only submit formal high estimates, creating a “pre-arranged race.” It appears to the management association that “proper comparative estimates were obtained.”
② Collusion with Design Supervisors
While consultants contract at extremely low design supervision fees, they receive kickbacks from the high construction costs of partnered construction companies. Design supervision fees that are too low are a warning sign.
③ Back Margin
A certain percentage of the contract amount is kicked back, which is then added to the construction costs as an expense. As a result, the management association ends up paying extra.
Source: Yokohama City “What is collusion in large-scale repair work for condominiums?” / Ministry of Land, Infrastructure, Transport and Tourism “On the Proper Ordering of Large-Scale Repair Work for Condominiums” (Notification dated April 3, Reiwa 5, PDF)
Self-Defense Measures for Management Associations
- Obtain independent estimates from multiple companies
- Consult with neutral third parties such as condominium management specialists or architects
- Document the vendor selection process in minutes to ensure transparency
- Confirm the reasons for unusually low design supervision fees from consultants
- Include a penalty clause in the contract for cases of collusion discovery
- Avoid concentrating information with a single consultant and verify specifications by the management association itself
Contact Points for Third-Party Consultation
If you are unsure about reading estimates or how to proceed with vendor selection, consulting with a third party separate from the construction company can be effective. The main contact points available for management associations in Zama City are as follows.
| Contact Point | Details |
|---|---|
| Zama City Urban Development Division Guidance Section | Phone 046-252-7396. This is the city’s contact point regarding condominium management and management plan certification system. |
| Condominium Management Plan Certification System Consultation Dial | Phone 03-5801-0858 (10 AM to 5 PM, excluding Sundays, holidays, and year-end/New Year). A condominium management specialist will answer questions about certification standards and application procedures. |
| Kanagawa Prefecture Condominium Advisor Dispatch Project | Dispatch of condominium management specialists and architects to management associations free of charge. You can also consult about how to proceed with large-scale repair work and general meetings. The application period for Reiwa 8 is until February 26, Reiwa 9 (may close early if there are many applicants). |
Source: Zama City “Condominium Management Plan Certification System” / Kanagawa Prefecture “Condominium Advisor Dispatch Project”
Frequently Asked Questions about Large-Scale Repairs in Zama City
- How much does large-scale repair in Zama 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 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 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 according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey is most commonly 13 years, 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 deterioration of sealing, tile lifting, or breaks in the waterproof layer are observed, it is better to carry out repairs without waiting for the cycle, as this can ultimately reduce costs. In Zama City, about 60% of condominiums are over 30 years old (as of fiscal year 2023, according to the city’s plan), and there is a tendency for the proportion of tile repairs and steel part replacements to increase during the second and third repairs.
- How long does the construction period take? Can residents stay during the work?
- For apartments, the construction period is approximately 3 weeks to 2 months, for small condominiums or buildings about 1.5 to 3 months, and for condominiums with over 50 units 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 hanging laundry outside and opening windows, so we take thorough measures to minimize the impact on daily life, including distributing advance notices, providing information on the schedule and laundry 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, building diagnosis, 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 required to obtain management plan certification (from preliminary confirmation by the condominium management center to city certification).
- Are there any subsidies available for large-scale repairs in Zama City?
- There are no subsidies specifically for large-scale repair work in Zama City or Kanagawa Prefecture. However, for condominium owners, if certain conditions are met, there is a one-third reduction in fixed property tax under the “Condominium Longevity Promotion Tax System,” subsidies from Zama City for seismic diagnosis costs for condominiums built before May 1981 (up to half, with a maximum of 1,500,000 yen per case), and free dispatch of condominium advisors from Kanagawa Prefecture. 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 program, so please check the eligibility conditions and application procedures for each program before contracting or starting construction.
- I heard that fixed property taxes can be reduced through 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 (such as being over 20 years old and having more than 10 units) conducts large-scale repairs that contribute to longevity (including exterior painting, floor waterproofing, and roof waterproofing), the fixed property tax amount for the following year will be reduced by one-third in Zama City (up to the equivalent of 100 square meters per unit). The eligible work must be completed between April 1, 2023, and March 31, 2027, and a special application form must be submitted to Zama City’s Fixed Property Tax Division 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 before the construction.
- Are there any changes to subsidies starting from the fiscal year 2026?
- Yes, there are. The national “Child-Rearing Green Housing Support Project” has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Management associations and management corporations can also become joint project participants, allowing for insulation renovations in common areas. Additionally, the “Long-Term Excellent Housing Renovation Promotion Project” will end in fiscal year 2025, and there will be no implementation in fiscal year 2026. The “Advanced Window Renovation 2026 Project” has begun accepting bulk applications for collective housing starting May 29, 2026 (the application process is handled by registered contractors). Please be careful not to base your financial planning on outdated information.
- What should I do if the repair reserve fund is insufficient?
- There are mainly four options: ① Postpone low-urgency work based on deterioration diagnosis to the next time, ② Review the scope and specifications of the work, ③ Check support systems such as subsidies, ④ Consider increasing the repair reserve fund or financing from the Japan Housing Finance Agency. The Agency’s condominium common area renovation loan does not require collateral, and by obtaining management plan certification and implementing energy-saving and seismic work, the interest rate can be reduced by up to 0.6% per year. Please note that postponing waterproofing and tile peeling measures often ends up being more expensive, so please consult us for a decision on separation.
- In Zama City, there are slopes and plateaus, but can scaffolding be set up on top of retaining walls or on sloped land?
- Yes, it can. In Zama City, the eastern part is the Sagamino Plateau and the western part is the Sagami River’s riverbank plateau and lowland, with an elevation difference of about 64m within the city. Kakeru Koumuten Co., Ltd. owns its own scaffolding materials and has its own scaffolding team, allowing us to plan the support and layout of the base plates after confirming the site. This is a part where additional costs are likely to arise after seeing the site, so it is important to confirm the delivery route during the estimation stage. We also check the deterioration of retaining walls and slopes and consult whether they are included in the long-term repair plan.
- What happens to the residents’ parking during construction?
- Vehicles on the side where scaffolding is to be erected will need to be temporarily moved. In buildings where there is limited space in the on-site parking lot, it may take time to secure an alternative location. Kakeru Koumuten Co., Ltd. will coordinate with you about the availability of nearby coin parking and monthly parking lots starting 2 to 3 months before construction begins.
- Can I freely decide the color of the exterior walls?
- In Zama City, the entire area is designated as a landscape planning zone, and repairs that change the appearance of buildings exceeding 15m in height or a building area of 1,000㎡ are subject to notification if the visible area of the repaired part exceeds 1,000㎡ or more than half of the total visible area. Color standards are established for the base color of exterior walls (hues R, YR, and Y must have a saturation of 6 or less, while others must have a saturation of 3 or less, excluding accent colors that are less than one-fifth of the visible area). Additionally, there are areas in the city’s eight district plans that require consideration of harmony with the surroundings for roof and exterior wall designs. Please check with the Urban Planning Department of Zama City Hall (main line 046-255-1111) to see what regulations apply to your property. We will also investigate this during our survey. Sharing a color simulation to visualize the completed image can facilitate discussions.
- Why is the north-facing exterior wall so badly affected by moss and algae?
- The north side receives less sunlight throughout the day, and when shadows from trees or neighboring buildings overlap, moisture can accumulate, making it easier for algae, moss, and mold to thrive. Zama City has areas with sloped green spaces and residential forests, which can increase the likelihood of this issue. After thoroughly cleaning with high-pressure washing, choosing paint with anti-algae and anti-mold properties can help prevent recurrence. Additionally, we recommend checking for blockages in roof drains and gutters caused by fallen leaves, as these can often lead to puddles on the roof and cause leaks.
- Which should I choose, the responsibility construction method or the design supervision method?
- In buildings with fewer units, the burden of consulting fees tends to be heavier, so we believe that the responsibility construction method is often more suitable for small to medium-sized buildings with fewer units. The design supervision method allows for comparison of construction companies under the same conditions since a third party creates the specifications; however, consulting fees are incurred separately, and there are risks of conflicts of interest and collusion that need to be considered. Even with the responsibility construction method, verifying price, specifications, and construction status is essential. Kakeru Koumuten Co., Ltd. provides estimates that clearly state quantities, methods, and materials for each work item, allowing for comparison on the same level as other companies.
- How can I detect collusion in large-scale repairs?
- There are three typical methods: ① Pre-determining the contractor and having other companies submit only formal high estimates, known as “dummy estimates,” ② A consultant contracts at an extremely low design supervision fee and receives kickbacks from affiliated contractors, 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. If there are too many, it becomes difficult to compare; if there are too few, competition does not occur. What is important is not the number of companies but “creating the same level of comparison.” By creating a common specification sheet and quantity table 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 range or unit price.
- What is the difference if you own your own scaffolding?
- Among the costs of large-scale repair work, temporary construction accounts for about 20% (according to the Ministry of Land, Infrastructure, Transport and Tourism’s fiscal year 2021 survey). By not outsourcing scaffold work, we can easily control costs in this area, and our in-house scaffold team can flexibly respond to sudden changes in the schedule or additional work. Kakeru Koumuten Co., Ltd. owns scaffold materials for approximately 100 single-family homes and plans according to the site conditions, even in areas with elevation differences like Zama City.
- Can I just have a look at the estimate while I’m comparing 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 we will provide you with an estimate under the same conditions. We welcome comparative 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 suggest 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 investigators of buildings containing asbestos materials. We handle everything from the legally required preliminary investigation to the cover method and removal of asbestos-containing roofing materials. Please check with the Zama City and Kanagawa Prefecture offices regarding the availability and conditions of assistance programs in case sprayed asbestos is found. We will also provide guidance based on the investigation results.
- What happens if I don’t carry out large-scale repairs?
- There are risks such as personal injury from falling exterior wall tiles, structural deterioration due to corrosion of rebar, leaks, and a decrease in asset value. Furthermore, 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 ten years have passed since completion or exterior wall renovations for tiles or mortar finishes. Zama City is an area under the jurisdiction of Kanagawa Prefecture, and only “service-equipped housing for the elderly” is designated as a target use for collective housing; buildings that are only condominium apartments or rental apartments are not designated as target uses. Mixed-use buildings, including stores, require individual confirmation. Even if not subject to statutory investigations, regular inspections and maintenance are essential, so please consult us if you are unsure about your judgment.
- How much does large-scale repair for an apartment (about 10 units) cost?
- For a wooden two-story building with 6 to 10 units, the estimate is around 2 million to 4 million yen, and for a three-story steel or RC building with 10 to 20 units, it is around 4 million to 9 million yen based on our company’s track record (including scaffolding, substrate repairs, exterior wall painting, sealing, and waterproofing). It is common to carry out repairs for apartments every 10 to 15 years. For owners, there is an increasing trend to change the appearance with color simulations during repairs to improve occupancy rates.
If you are looking for a large-scale repair contractor in Zama City, contact Kakeru Koumuten Co., Ltd.
Our company handles many exterior wall renovations and large-scale repairs for condominiums and apartments in Zama 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 scaffold work to roofing and exterior wall painting, all work is performed by our own team. We are confident that we will not be outdone in terms of cost, quality, and planning compared to other companies, so we welcome comparative estimates!
On-site surveys, estimates, and color simulations are all free of charge
Please feel free to consult us via the inquiry form, phone, or LINE.
It’s fine to just present estimates from other companies.
Areas Covered for Large-Scale Repair Work
Kakeru Koumuten Co., Ltd. accepts requests for work throughout Kanagawa Prefecture and Tokyo.
Iriya Nishi / Iriya Higashi / Kurihara / Kurihara Chuo / Komatsubara / Sagami Gaoka / Sagamino / Zama / Nitta Shuku / Sobudai / Tatenodai / Nishi Kurihara / Higashihara / Hibarigaoka / Hirono Dai / Midorigaoka / Minami Kurihara / Myouou / Yotsuya
・When should large-scale renovations be carried out? Explanation of the optimal timing and risks of postponement!
・Estimates are essential for large-scale renovations! Key comparison points and precautions!
・5 common troubles in large-scale renovations of condominiums! Thorough explanation of causes and prevention measures!
・What is waterproofing work in large-scale renovations? Thorough explanation of roles, signs of deterioration, and precautions!
・Not enough funds for large-scale renovations… Explanation of how to deal with funding shortages and preparations you can do right now!
・What is important substrate repair in large-scale renovations? Thorough explanation of necessary reasons, signs of deterioration, and types of work!
・What is sealing work in large-scale renovations? Introduction to roles, methods, and tips for avoiding failures!
・What is important tile repair in large-scale renovations? Explanation of signs of deterioration, types of work, and cost averages!
・What is important exterior wall painting in large-scale renovations? Thorough explanation of necessity, signs of deterioration, and cost averages!
・For exterior renovations in Zama City, Kanagawa Prefecture, trust Kakeru Koumuten!
・For roof renovations in Zama City, Kanagawa Prefecture, trust Kakeru Koumuten!
・For exterior wall painting in Zama City, Kanagawa Prefecture, trust Kakeru Koumuten!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!



