Leave the repairs and renovations of condominiums and apartments in Midori, Sagamihara City to Kakeru Koumuten Co., Ltd.!
Large-Scale Repairs for Condominiums, Apartments, and Buildings in Midori Ward, Sagamihara City
To owners, management associations, and management companies considering large-scale repairs for condominiums, apartments, and buildings in Midori Ward (Sagamihara City).
Kakeru Koumuten Co., Ltd. is a company that handles everything from the installation of temporary scaffolding to substrate repairs, exterior painting, tile repairs, sealing, waterproofing for rooftops and balconies, and roofing work, all managed and performed by our own team. In Midori Ward, 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)
- Comprehensive management from temporary scaffolding to exterior and roofing work
- Our own scaffolding team will handle sites with slopes and elevation differences after confirming the location
- 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 (according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for the 3rd year of Reiwa, about 70% fall within this range, 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 determining factor is not the number of years but the condition of deterioration.
- Particularly Relevant in Midori Ward / Considerations for slopes and retaining walls in mountainous areas connected to the Tanzawa Mountain Range and potential landslide disasters, flooding and internal water considerations for the Sagami River, transportation and neighborhood considerations in the redevelopment around Hashimoto Station and industrial areas, and confirming the appearance and procedures due to district plans and building agreements.
- Available Funds / There are no subsidies specifically for large-scale repairs, but if requirements are met, there is a 50% reduction in fixed asset tax (for work completed by the end of March in Reiwa 9), and national subsidies may be available if windows and insulation are included, as well as public financing.
- Tips for Success / At least three competitive estimates. Compare not only the amounts but also the quantities, methods, and materials.
Large-scale repair work that can be handled in Midori Ward, Sagamihara City
Large-scale repairs are not just “exterior wall painting” or “waterproofing,” but a comprehensive repair work that addresses the deterioration of the entire 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 Content |
|---|---|
| Temporary Scaffold Work | Installed by our own scaffold team using our owned scaffold materials. Includes 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 (metal parts, gutters, water cut-offs, etc.). Supports 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 installation of long sheets. |
| Roof Work | Roof painting, roof overlay (cover method), re-roofing, and ridge cap replacement. Skilled metal workers are available to handle large roofs such as factories. |
| Metal and Hardware Work | Surface 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. Blockages in drainage can lead to puddles on rooftops and leaks, so inspection and cleaning are essential works. |
| Others | Replacement of rain gutters, rooftop and exterior wall inspections using drones, leak investigations using thermography, and preliminary surveys of asbestos-containing building materials. |
Scope of Major Repairs Determined by Building Diagnosis
It is not guaranteed that all the above works will be carried out. The extent of the work will be determined based on the results of the building diagnosis. At Kakeru Koumuten Co., Ltd., we conduct a free on-site survey to confirm the items below, compile a deterioration diagnosis report with photos, and propose the scope of work.
| Diagnosis Area | Main Inspection Method | Scope of Work Determined by Diagnosis Results |
|---|---|---|
| Exterior Wall (Painted Surface) | Visual inspection, checking the width of cracks and the condition of the paint film | Method and quantity of crack repairs, painting specifications (repainting or painting after removing the existing paint film) |
| Exterior Wall (Tile Surface) | Sounding inspection. 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, the scope of joints to be worked on |
| Roof, 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 | Investigation using thermal imaging camera and drone | Identification of the cause and the scope of repairs to prioritize |
| Metal Parts, Roof, Accessories | Checking for rust, corrosion, lifting, and cracking. For buildings near the sea, checking the progression of rust due to salt | Whether it can be resolved with painting or if material replacement or cover method is necessary |
| Site and Surroundings | Checking slopes, retaining walls, embankments, trees, delivery routes, and parking areas | Planning for scaffolding and the scope of temporary construction |
Reasons Kakeru Koumuten is Chosen for Large-Scale Repairs in Midori Ward, Sagamihara City
The reason why we can be entrusted with large-scale repairs in Midori 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 Ownership of 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 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 Sorting of Waste Materials
Large-scale repairs generate various waste materials such as leftover paint, metals, 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 heat insulation tests using a heat insulation testing machine are also available!
2. Cost Reduction through In-House Management and Construction
One of Kakeru Koumuten’s major strengths is in-house management and construction.
From inquiry to project completion, everything is managed by Kakeru Koumuten in a consistent system, allowing for high-quality large-scale repairs at reduced costs. Additionally, one representative will handle everything from the estimate to project completion. Since the person in charge does not change, whether it be sales or construction management, smooth communication is possible.
We can handle everything from temporary scaffolding installation to exterior wall painting, substrate repair, 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. Obtaining Various Permits and Skilled Workers
We have obtained construction industry permits and permits for industrial waste collection and transportation! We also have national certified sheet metal and painting specialists on staff, and we are confident in our construction techniques. We can also handle large-scale roofing projects for factories! We have qualified personnel for asbestos work supervisors and building materials containing asbestos investigators, so we can manage asbestos-containing roofing materials and conduct preliminary investigations.
4. Warranty and Aftercare
Large-scale repair work comes with warranties for most projects, including “painting work,” “substrate repair work,” and “waterproofing work”!
Aftercare is available every year, and we send out notification DM each year.
5. Flexible and Prompt Response
Our company is equipped to handle various troubles and situations related to apartments and condominiums.
We can address exterior walls and rooftops that cannot be checked from high places by utilizing a drone! During rain leak investigations, we can also use 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 rain leaks! We will promptly respond to urgent requests!
6. Staff Development
Our staff creates various models for skill improvement and conducts practical training. Since different processing and techniques are required at each site, we regularly provide skill enhancement education to ensure each staff member can respond appropriately. We also educate on points to be careful about and areas to check during each stage of large-scale repair work.
7. Consideration for Residents and Neighbors
During large-scale repair work, we not only notify residents and greet neighbors, but we also set up notice boards 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 stage is inspected by a responsible person, and detailed construction photos are taken. We use film thickness testers and check sheets to ensure there are no oversights during inspections. When performing exterior wall painting or waterproofing work, we check the quantity of used paint cans to confirm that the specified amount of paint is being used, and we prevent construction defects by ordering paint in-house. Of course, we will also take photos of the used paint and report them.
9. Color Simulation for Exterior Wall Painting
9-1 Self Color Simulation
The simulations created by our company can be done using photos of your actual apartment or building!You can also perform simulations on your smartphone or computer. By simulating and then changing to a two-tone color or making an image change, we hope to help enhance the stylish appearance and increase occupancy rates! Of course, we can also arrange paint samples for actual color confirmation.
*In Midori Ward, there are district planning areas around Hashimoto Station, Aihara, and Kawajiri, as well as areas with building agreements. When changing the color of the exterior walls, there may be procedures and standards in place. Having a color simulation screen can help facilitate explanations at the management association’s general meetings or community meetings.
9-2 Confirm the actual color with a trial paint!
You can order samples of the paint you are considering and perform a trial paint on your exterior wall. By conducting a trial paint, you can confirm the actual color and gloss!
9-3 Exterior renovation simulation
Exterior simulations for apartments and condominiums are also possible!
・Exterior wall color simulation (two-tone colors are also possible)
・Simulation for applying metal siding
・Simulation using accent materials such as cornices and louvers
・Simulation for roof painting or roof replacement work
With exterior renovation simulations, you can minimize the risk of failure in image changes! We hope that renovating the appearance of your apartment or condominium will help increase occupancy rates.
Estimated Costs for Major Repairs in Midori Ward, Sagamihara City
The costs for major repairs vary significantly depending on the size of the building, its condition, the scope of work, and the materials used. First, please refer to the national average based on official statistics, then to our company’s estimates based on past projects categorized by size, and finally to examples of unit prices for specific projects.
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 repairs are concentrated in the range of 750,000 to 1,500,000 yen per unit, with the most common price range being 1,000,000 to 1,250,000 yen. Note that this survey’s figures do not include consumption tax and common temporary 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 yen | 15.1% | 1,250,000 to 1,500,000 yen | 17.4% |
| 750,000 to 1,000,000 yen | 24.7% | 1,500,000 to 2,000,000 yen | 9.1% |
| 1,000,000 to 1,250,000 yen | 27.0% (most common) | Over 2,000,000 yen | 2.8% |
Source: Ministry of Land, Infrastructure, Transport and Tourism “FY 2021 Survey on Major Repair Works for Condominiums” (200 companies, 818 cases) *The amounts do not include consumption tax or common temporary costs. The 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 Work | 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 major repair defect insurance (0.8%) |
Source: Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Renovation Works for Condominiums” (Second survey of large-scale renovation works. The overall average is 59.0% for construction-related costs, 22.3% for temporary works, and 9.9% for miscellaneous expenses). *The total does not equal 100% because it includes equipment-related works, external works, and others. This is an average value and is not a criterion for judging the appropriateness of individual estimates.
Cost Estimates by Building Size (Scaffolding, Substrate Repair, Exterior Painting, Waterproofing, Sealing)
| Type and Size of Building | Cost Estimate | 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 Condominium (4-5 stories) | 5,000,000 – 15,000,000 JPY | 1.5 – 3 months |
| Medium-Sized Condominium (30-50 units) | 20,000,000 – 50,000,000 JPY | 3 – 5 months |
| Large Condominium (over 100 units) | Around 100,000,000 JPY or more | 6 months or more |
*The above is an estimate based on Kakeru Koumuten’s construction performance and may vary depending on the presence of roofing works, metal works, 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 Works, Substrate Repair, Exterior Walls, and Waterproofing
The estimate for large-scale renovations is broadly divided into “temporary works,” “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.
| Item | What to Confirm in the Estimate |
|---|---|
| Building Prerequisites | Structure (wooden, steel frame, RC), number of floors, number of units, exterior wall area, waterproof area. Confirm whether the area is based on drawings or actual measurements. |
| Common Temporary Works & Scaffolding | Area and unit price of scaffolding, mesh sheets, protective measures, temporary toilets, etc. According to the Ministry of Land, Infrastructure, Transport and Tourism’s survey for Reiwa 3, temporary works like scaffolding account for about 20% of construction costs (excluding common temporary costs). |
| Substrate Repair | Quantities and unit prices for repair methods such as cracks, lifting, and spalling. Since these items are not confirmed until scaffolding is assembled, confirm whether it will be based on estimated quantities or actual settlement, and the settlement method if quantities increase or decrease. |
| Sealing | Whether it is a replacement or additional sealing, length to be applied (m), and material name. |
| Exterior Wall 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 roof, balcony, and common corridor, construction method, material name, and whether drain renovation is included. |
| Inspection & Reporting | Inspections for each process, construction photos, and whether the completion report and warranty are included. |
| 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 Reiwa 3, the average is about 10% of construction costs, but it varies depending on the size and conditions of the building, so there is no uniform standard. |
| Tax Classification | Whether the amount is tax-inclusive or tax-exclusive. Since the display varies by company, be sure to standardize 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） |
| Concrete Spalling Repair | 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 based on shape, quantity, substrate condition, and type of materials. If you would like a detailed estimate, please feel free to contact us. Estimates are completely free.
Select Paint and Waterproofing Grades Based on “Years Until Next Repair”
“Good paint does not equal the right choice.” The best way to choose is to align when the next major repair will be with the lifespan of the materials to avoid waste.
| Grade | Estimated Lifespan | Suitable Cases |
|---|---|---|
| Silicone / Radical Control Type | 10-16 years | Buildings that are cycled every 12-15 years. A good choice balancing cost and performance. The lifespan varies by product, so choose specifications that match 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. Effective for areas with poor sunlight and areas prone to algae and moss due to moisture around water. |
| Urethane Waterproofing (Rooftop) | 8-15 years | Complex-shaped rooftops, when wanting to renovate using 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 a large area and simple shape. The construction period is short. |
| Asphalt Waterproofing | 15-20 years | Rooftops planned for a long cycle. The cost per instance will increase. |
* The estimated lifespan is a general guideline and may vary depending on sunlight, location, and substrate condition. For areas exposed to strong rain, wind, and sunlight, choosing high-weather-resistant paint and specifications that include rust prevention for metal parts after cleaning will improve durability.
Guidelines for Repair Reserve Funds and Options When Insufficient
The Ministry of Land, Infrastructure, Transport and Tourism guidelines indicate the estimated repair reserve fund on a monthly basis per exclusive area. Additional charges are necessary if there is a mechanical parking lot.
| Building Scale (Less than 20 Floors) | 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 comprehensive survey for the fiscal year Reiwa 5, 36.6% of management associations responded that “the repair reserve fund is insufficient compared to the plan.” When there is a shortfall, there are four main options.
| Options | Considerations and Cautions |
|---|---|
| ① Adjusting the Construction Schedule | Based on 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 peeling measures will ultimately be more costly. |
| ② Reviewing the Scope and Specifications of Work | Reassessing paint grades, changing from full renovation to partial renovation, etc. Please consider this separately from “apparent 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 individual owner, and does not directly increase the repair funds of the management association. |
| ④ Increasing the Reserve Fund, Borrowing, or One-Time Payments | In addition to considering an increase in the repair reserve fund at the general meeting, the Housing Finance Agency’s condominium common area renovation loan requires no collateral. Interest rates can be lowered by obtaining management plan certification. |
Subsidies, Tax Systems, and Loans to Check for Large-Scale Renovations in Midori Ward, Sagamihara City
The list of housing assistance and subsidy systems in Sagamihara City does not include subsidies specifically for large-scale renovation work on condominiums (Kanagawa Prefecture also does not have subsidies aimed at the work itself). The types available can be broadly categorized into four. 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 relevant offices before contracting or starting work. (As of October 8, 2026)
| Type | Details |
|---|---|
| ① Support for Consultation and Planning | Free consultations with experts, dispatch of advisors, and management plan certification. Useful for pre-construction phases of large-scale repairs such as deterioration diagnosis and review of long-term repair plans. |
| ② Construction Subsidies by Purpose | Energy-saving (windows, insulation), earthquake resistance, etc. Incorporated into large-scale repairs. |
| ③ Tax Incentives | Reduction of property tax under the condominium longevity promotion tax system. |
| ④ Public Financing | Housing Finance Agency’s loan for condominium common area renovations. |
① Condominium Longevity Promotion Tax System (Property Tax Reduction)
If large-scale repairs (such as exterior painting, floor waterproofing, and roof waterproofing) contributing to the longevity of condominiums that meet certain requirements are carried out, the property tax amount for the following year will be reduced by half (the reduction lasts for one year, and if the residential floor area exceeds 100㎡, the reduction applies only to 100㎡; urban planning tax is not reduced).
| Main Requirements | Built for over 20 years, more than 10 units / Previously completed longevity construction (exterior painting, floor waterproofing, roof waterproofing) / Must meet one of the following: ① A certified management plan condominium that has raised the amount of the repair reserve fund from below the national standard to the management plan certification standard ② A condominium managed by a management association that has received advice and guidance from the city, which has created or reviewed a long-term repair plan that meets certain standards. |
|---|---|
| Construction Implementation Deadline | Completion of the second or subsequent longevity construction between April 1, Reiwa 5 and March 31, Reiwa 9 (2027). |
| Declaration | Declare within three months after the completion of the work to the Asset Tax Division (Building Evaluation Group 1) of the Finance Bureau of Sagamihara City. Required documents include the specific condominium declaration form, proof of large-scale repairs, proof of past work, and documents showing that there are more than 10 units (such as floor plans); if certified management plan, a copy of the certification notification and proof of repair reserve fund increase are also required. |
| Notes | Simply obtaining management plan certification does not qualify; there are requirements such as increasing 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 the construction. The reduction requirements are guided by the Housing Policy Group of the Housing Division (042-769-9817). |
Source: Sagamihara City “Tax System for Promoting the Longevity of Condominiums” (Updated May 12, 2025) / Sagamihara City “Reduction of Property Tax for Condominiums Where Longevity Construction Has Been Carried Out” (PDF)
② Support for Condominium Management, Earthquake Resistance, and Energy Conservation in Sagamihara City (Management Associations Start Here)
The Housing Division of Sagamihara City supports those involved in condominium management through free consultation services, advisor dispatch, and condominium management seminars. Note that the dispatch of condominium advisors in Kanagawa Prefecture is targeted at management associations outside of Sagamihara City, and condominiums in Sagamihara City utilize the city’s system.
| System | Details |
|---|---|
| Free Consultation Window for Condominiums | This is a free consultation held on the first Monday of every month in principle. There is information on the city’s page (Contact: Housing Division 042-769-9817). Please confirm the date and whether a reservation is required before you go. |
| Condominium Advisor Dispatch System | Advance application is required. Experts such as condominium management consultants will provide advice on the operation of the management association, review of management regulations, large-scale repairs, rebuilding, etc. According to the city’s page (updated April 14, 2023), dispatch is limited to a total of 6 times, with the first time free, the 2nd and 3rd times at one-third of the cost, and the 4th to 6th times at half the cost (10,000 yen per hour, up to 3 hours per visit). Advice is given verbally, and the creation of repair plans or estimates is not included. The program will end when the budget is reached. |
| Condominium Management Seminar | The city holds this seminar once a year (please check the city’s page for the timing). |
| Seismic Support for Condominiums Built to Old Standards | This applies to reinforced concrete, steel-reinforced concrete, and steel condominiums that obtained construction confirmation and commenced construction before May 31, 1981. There is a subsidy for seismic diagnosis (up to 50,000 yen per unit) and a subsidy for the cost of creating a seismic retrofitting plan after diagnosis (within two-thirds of the cost, up to 50,000 yen per unit), both within the city’s budget. The subsidy amount for seismic retrofitting construction costs is not listed on the city’s page. The application period is also not specified on the page, so please confirm with the Building Policy Division (042-769-8252). |
| Incentives for Introducing Smart Energy Equipment for Homes (Reiwa Year 8) | This system targets solar power generation systems, stationary lithium-ion storage batteries, V2H, and ZEH. The application for the first phase has closed from September 1 to 30. The second phase will be from February 1 to 26, Reiwa Year 9 (must arrive by this date), targeting equipment completed between October 1, Reiwa Year 8 and February 26, Reiwa Year 9. It is not specified on the city’s page whether common areas of apartment buildings are included, so please confirm with the Zero Carbon Promotion Division (042-769-8240). |
Source: Sagamihara City “Consultation on Condominium Issues” (Updated October 21, 2020) / Sagamihara City “About the Condominium Advisor Dispatch System” (Updated April 14, 2023) / Kanagawa Prefecture “Condominium Advisor Dispatch” / Sagamihara City “Support for Earthquake Measures for Condominiums Built to Old Seismic Standards” / Sagamihara City “Incentives for Introducing Smart Energy Equipment for Homes” (Updated October 8, 2026) *Please note that the pages for advisor dispatch, consultation, and seismic measures may contain outdated information; please check with the consultation desk for current content.
③ Management Plan Certification System (Entrance to Tax and Interest Rate Benefits)
This is a system certified by Sagamihara City, and upon certification, you may receive interest rate benefits for the Housing Finance Agency’s “Condominium Common Area Renovation Loans” and Flat 35 (Maintenance Type), which is also one of the requirements for the Long-term Lifespan Promotion Tax System (certification alone does not guarantee tax reductions). The certification criteria cover five areas: management association operations, management regulations, accounting, long-term repair plans, and others (such as disaster prevention measures), with disaster prevention measures established as a unique standard by the city.
*The application fee for certification is 3,600 yen (new/renewal) if there is one long-term repair plan. If there are multiple plans, an additional 1,700 yen is charged per plan, and there are separate fees for the institution conducting the preliminary confirmation. The application process proceeds in the order of preliminary consultation (Housing Division), preliminary confirmation, certification application, and payment of fees. Consultations are available at the Housing Division (042-769-9817) as well as the Condominium Management Plan Certification System Consultation Dial (03-5801-0858, Monday to Friday 10:00 AM to 5:00 PM, excluding holidays and year-end/New Year).
④ National Energy Conservation Support | Housing Energy Conservation 2026 Campaign
Changes for Fiscal Year 2026The “Child-Rearing Green Housing Support Project” for Fiscal Year 2025 has been abolished and reorganized into the successor “Mirai Eco Housing 2026 Project.” Additionally, the “Long-term Excellent Housing Renovation Promotion Project” will end in Fiscal Year 2027 and will not be implemented in Fiscal Year 2028. 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 residences. Management associations and management corporations can also become joint contractors (i.e., can be used for renovations of common areas). Rental properties are also eligible. |
|---|---|
| Required Work | Insulation renovations of openings, insulation renovations of the structure (floor, walls, ceiling), and installation of eco-friendly housing equipment are mandatory combinations. |
| 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 homes built before 1991). |
| Period | Subsidy applications are generally made by registered contractors (construction contractors) after the completion of the work (the client cannot apply themselves). Reservations for subsidy applications must be made by November 16, 2026, at the latest, and applications must be submitted by December 31, 2026, at the latest (will end once the budget limit is reached). |
Advanced Window Renovation 2026 Project
| Target | Renovations to existing homes (single-family and multi-family) including the installation of inner windows, replacement of outer windows, and glass replacement to high-performance insulation windows. Subsidy rates are set separately for “low-rise” and “mid-to-high-rise” multi-family residences. |
|---|---|
| Bulk Application for Multi-Family Residences | As of May 29, 2026, applications for “bulk subsidy applications for multi-family residences (including reservations)” have begun. The application process is conducted by registered contractors (window renovation contractors), and management associations cannot apply themselves, but they can apply for all units collectively, making it a system that works well with large-scale repairs for window and entrance door renovations. |
| Subsidy Limit | For residences, 1,000,000 yen per unit (changed from 2,000,000 yen in fiscal 2025). For non-residential buildings over 240 square meters, 10,000,000 yen per building. |
| Period | Work must be started after November 28, 2025. Subsidy applications are made after the completion and handover of the work, with reservations due by November 16, 2026, at the latest, and applications due by December 31, 2026, at the latest (will end once the budget limit is reached). |
⑤ Kanagawa Prefecture Subsidies (Applications for Fiscal 2026 have ended)
| Existing Housing Energy Efficiency Renovation Subsidy | Houses (including exclusive parts of condominiums) that the applicant resides in and owns or has ownership in within the prefecture are eligible. Renovation of windows that are exposed to the outside air (including entrance doors, etc.) is mandatory. The subsidy covers one-third of the eligible expenses, or a maximum of 150,000 yen, whichever is lower. For the fiscal year 2026, applications were closed as of September 30 at 17:30 when the application amount reached the budget limit. Construction that commenced before the notification of grant decision is not eligible, and applications by contractors on behalf of the applicant are not permitted. |
|---|---|
| Subsidy for Residential Solar Power Generation and Storage Battery Installation | Management associations of condominium complexes in the prefecture are also eligible. Solar power is 70,000 yen/kW, and storage systems are 150,000 yen per unit. The second phase for the fiscal year 2026 was closed on September 7, the application start date, when the application amount reached the budget limit. If work commenced before the grant decision date, it is not eligible. This is a system to confirm if you are considering installing solar power along with rooftop waterproofing. |
* The Existing Housing Energy Efficiency Renovation Subsidy does not cover common areas of rental apartments or units where the owner does not reside.
⑥ Financing System (Housing Finance Agency Condominium Sumairu Loan)
If the management association borrows funds for large-scale repairs, they 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, and 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; for specific construction, 1 to 20 years; if seismic, flood, and energy-saving work is carried out after obtaining management plan certification, up to 35 years. |
| Interest Rate Reduction | ① Holding Sumairu Bonds ② Obtaining Management Plan Certification ③ Implementing seismic, flood, and energy-saving work can reduce the rate by 0.2% per year (up to 0.6% per year maximum). |
| Main Requirements | Improvement of management regulations, resolutions at general meetings, 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 the scattering of rooftop waterproof sheets, coping, and fences due to typhoons or strong winds, hail damage, and lightning strikes may be covered by fire insurance. It is important to clearly document the distinction between damage from accidents and wear and tear during the deterioration diagnosis.
On the other hand, wear and tear itself is not covered. There have been numerous troubles nationwide with contractors soliciting, saying “You can repair it without any out-of-pocket expenses with insurance,” and the Consumer Affairs Agency has repeatedly issued warnings. False claims can lead to insurance fraud charges. Please confirm the eligibility of your claims directly with your management association or property owner to the insurance company or agent. Kakeru Koumuten Co., Ltd. does not provide such guidance.
Building Conditions and Repair Points in Midori Ward, Sagamihara City
Midori Ward in Sagamihara City is one of the three wards of Sagamihara City, covering an area of 253.9 km², making it the largest ward, accounting for 77.2% of the city area. The eastern part of the ward is an urban area where industrial, commercial, and business functions are concentrated, such as in the Hashimoto area, while the western side is the Tsukui region, characterized by forests, lakes, and rivers. The western part is part of the Tanzawa mountain range, with the highest peak, Hirugatake, at an elevation of 1,673 m. It includes the Sagami River, Doshi River, Lake Tsukui, and Lake Sagami, and is part of Tanzawa-Oyama National Park and Kanagawa Prefectural Jinba Sagami Lake Natural Park. The area around Hashimoto Station is undergoing urban redevelopment as a transportation hub, and Ooyama Town has been designated as an emergency urban regeneration area, with the Kanagawa Station of the Linear Chuo Shinkansen also decided to be in the Hashimoto area. The city’s “Basic Plan for Midori Ward” (around October 2019) states that the area around Hashimoto Station has supported the development of an inland industrial city, and within the ward, there are the Sagamihara Machinery and Metal Industrial Park and the Kyō no Hara Industrial Park. The coexistence of urban areas around Hashimoto Station and the distinct characteristics of mountains, lakes, and rivers in Tsukui within a single ward serves as a starting point for considering large-scale repairs in Sagamihara Midori Ward.
(as of April 1, Reiwa 7)
3rd among the 3 wards of Sagamihara City
(as of April 1, Reiwa 7)
3rd among the 3 wards of Sagamihara City
(as of January 1, Reiwa 8, excluding unspecified ages)
Highest in the city as of January 2019
77.2% of the city area
1st among the 3 wards of Sagamihara City
(as of January 1, Reiwa 8)
Source: Sagamihara City “Current Status of the City” (Population and Household Numbers as of April 1, Reiwa 7)／Sagamihara City “Overview of Midori Ward” (As of January 1, Reiwa 8)／Midori Ward “Ward Profile” (Updated January 16, 2018)／Sagamihara City “Basic Plan for Midori Ward” (Report around October, Reiwa 1) *The ranking is based on the numerical values in the table, arranged from the largest (widest) ward.
Let’s also check the composition of generations and households. As of January 1, Reiwa 8, the age distribution in Midori Ward is as follows: the youth population (ages 0-14) is 9.8%, the working-age population (ages 15-64) is 60.0%, and the elderly population (ages 65 and over) is 30.1% (percentage based on 161,688 people excluding 4,262 people of unknown age). According to the city’s “Basic Plan for Midori Ward,” the percentage of elderly people as of January 1, 2019, was 27.6%, which was the highest in the city. Calculating from the population and number of households, there are approximately 2.1 people per household. These figures represent the entire ward and do not indicate the situation of individual building residents; the generational composition varies by location within the same ward.
Buildings in Midori Ward are divided into “three faces”
Midori Ward has significantly different environments depending on the area: the urban area of Hashimoto, the Oosawa and Shiroyama areas along the Sagami River, and the mountainous regions of Tsukui, Sagamiko, and Fujino. The major repairs that will be required in your next large-scale renovation will vary depending on where your building is located. Please note that the history of rebuilding and large-scale renovations differs for each building, so the age of the building should be viewed as a guideline.
| History of the Town | Representative Locations | From Development | Heavy Construction in Next Repairs |
|---|---|---|---|
| Urban Area Around Hashimoto Station Surrounding areas such as Hashimoto, Nishi-Hashimoto, Higashi-Hashimoto, Hashimoto-dai, Aihara, and Oyama Town |
The Hashimoto area consists of three regions: Aihara, Hashimoto, and Miyakami, centered around Hashimoto Station, serving as a transportation hub where commercial, business, and industrial functions gather. A city redevelopment project is underway in front of the station, and the Kanagawa Prefecture station for the Linear Chuo Shinkansen has been decided. There are district plans for areas such as Hashimoto Oyama Town, the south exit of Hashimoto Station, Hashimoto Urban Core Area, Nishi-Hashimoto 1-chome Area, and Aihara 4-chome and 5-chome Areas. | The annual data is not recorded in city documents and varies by property. | For buildings housing stores and offices, and mid to high-rise buildings near the station, the focus will be on scaffolding and delivery planning on busy roads, rooftop waterproofing, and checking the condition of exterior wall tiles and sealing. In areas close to factories and businesses, care must also be taken regarding the dispersion of cleaning and the smell of paint. |
| Osawa and Shiroyama Along the Sagami River Surrounding areas such as Oshima, Ogura, Kawajiri, Shiroyama, and Harajuku |
The Osawa area features campsites and walking paths that utilize the natural environment of the Sagami River. The city has published hazard maps for landslide disasters for the Hashimoto-Osawa area and the Shiroyama area (created in March 2022). Flood hazard maps based on inundation assumption area maps for the Sagami River (downstream from Ogura Bridge) have also been published. There is a district plan in Kawajiri. | The annual data is not recorded in city documents and varies by property. | For waterproofing around the first floor, basement, and mechanical rooms, as well as protection around external piping and electrical equipment, the focus will be on the condition of slopes and retaining walls. Since assumptions differ by site, necessary ranges will be specified in estimates after checking the site conditions on the hazard maps. |
| Mountain Areas of Tsukui, Sagamiko, and Fujino Surrounding areas such as Mikagi, Aoyama, Sagamiko, Fujino, Aone, and Aonohara |
The Tsukui area is rich in nature as a water source with forests and lakes, and the Sagamiko and Fujino areas have tourism and cultural facilities. Landslide hazard maps are published separately for the Tsukui area (three maps), Fujino area (two maps), and Sagamiko area (one map). Flood assumptions for rivers flowing within the district, such as the Doshi River and Kushi River, are also published. | The annual data is not recorded in city documents and varies by property. | For buildings located on slopes or in valleys, the focus will be on the foundation of scaffolding, the delivery route for materials, and the condition of retaining walls and slopes. In sites with narrow delivery routes, it will be confirmed during the estimation phase whether large vehicles can access the site. For buildings close to forests, checks for blockages in drains and gutters caused by fallen leaves will also be conducted. |
Source: Midori Ward “Ward Profile” (Updated January 16, 2018. Characteristics of each area) / Midori Ward “Hashimoto Area” (Updated October 3, 2025. Urban redevelopment projects, Linear station, Oyama Town) / Sagamihara City “District Plans in the City” (Updated February 3, 2025) / Sagamihara City “Landslide Hazard Map” (Updated April 23, 2026) / Sagamihara City “Flood Hazard Map” (Updated April 23, 2026) *The correspondence of area names and locations is organized by our company based on the district names and town names listed in the city’s materials.
Four Factors Unique to Midori Ward That Damage Buildings
The contents of large-scale repairs vary depending on the location of the building. When investigating buildings in Midori Ward, the following four factors should be particularly checked. This is based on overall trends in the ward, but the actual conditions differ for each building, so be sure to confirm on-site.
① Slopes in mountainous areas and along rivers, and the assumption of landslide disasters
The western part of Midori Ward is part of the Tanzawa mountain range, featuring forests, lakes, and rivers. Sagamihara City’s landslide hazard map divides Midori Ward into Hashimoto, Osawa, Shiroyama, Tsukui (three areas), Sagamiko, and Fujino (two areas) (the map primarily created in March 2022, with designated warning areas based on the time of creation. The latest designations can be confirmed through Kanagawa Prefecture’s announcement documents). Buildings located on sites with slopes, stairs, and retaining walls have different requirements for scaffolding foundations and material delivery routes compared to flat land. Check whether the condition of retaining walls and slopes is included in the long-term repair plan, and clarify the delivery route during the estimation phase.
② Assumptions of flooding and internal water from the Sagami River and others
The flood hazard map of Sagamihara City is based on the inundation assumption area maps of the Sagami River (downstream from the Ogurabashi area), Doshi River, and Kushigawa, among others (assuming maximum scale rainfall, approximately once every 1,000 years. Updated on April 23, Reiwa 8). The internal water hazard map has been published for the Midori Ward version (assuming that 153 mm of rain falls simultaneously across the entire city area in one hour. Updated on October 1, Reiwa 8). Since the assumptions differ for each site, it cannot be stated uniformly. The city has indicated that there is an error in the display of the “flood assumption area for building collapse, etc.” along the Sagami River, and plans to correct the relevant hazard map in the future. We will confirm the waterproofing around the first floor, basement, and mechanical room, and clearly state the conditions in the estimate.
③ Redevelopment around Hashimoto Station and consideration for nearby industrial and residential areas
The area around Hashimoto Station is a transportation hub where commercial and industrial functions gather, and a city redevelopment project is underway in front of the station. Oyama Town has been designated as an urgent urban regeneration area. Within the district, there are the Sagamihara Machinery and Metal Industrial Park and the Kyō no Hara Industrial Park, where residential and business locations are in close proximity. For buildings facing busy roads and bus routes around the station, we will identify the impact of scaffolding and material delivery times, as well as the dispersion of high-pressure washing and the smell of paint on the neighbors, and incorporate this into the construction process before starting work. The color and procedures for exterior walls will vary depending on the regulations applicable to the site.
④ Characteristics of a large area with a high percentage of elderly residents
Midori Ward is a large area that occupies 77.2% of the city, with significantly different environments from the urban area of Hashimoto to the mountainous region of Tsukui. As of January 1, Reiwa 8, the percentage of the elderly population (65 years and older) is 30.1%, which greatly exceeds the youth population of 9.8%. The ease of access and delivery routes to the site will be checked during the estimation stage, and notifications to residents will be provided in both distribution and bulletin boards, using clear and polite language. This is a trend across the entire ward, and the composition of residents and their home hours differ for each building.
Source: Sagamihara City “Landslide Hazard Map”／Sagamihara City “Flood Hazard Map”／Sagamihara City “Internal Water Hazard Map”／Midori Ward “Ward Profile”／Midori Ward “Hashimoto Area”／Sagamihara City “Overview of Midori Ward” (as of January 1, Reiwa 8)／Sagamihara City “District Plans in the City”／Sagamihara City “Overview of Building Agreements in the City” (Updated December 14, 2021)
Key Points to Consider When Proceeding with Construction in Midori Ward
| Issue | Current Situation in Midori Ward and Kakeru Koumuten’s Response |
|---|---|
| District Planning, Building Agreements, and Landscape Plans | The procedures and considerations for exterior wall colors may change depending on what is applicable to the property. In Midori Ward, there are district planning areas around Hashimoto Station, Aihara, and Kawajiri, and names like Hashimoto Life Town and Wakabadai Housing Complex appear on the city’s list of building agreements. Sagamihara City’s landscape plan targets buildings of certain heights and sizes for notification, and whether large-scale repairs are applicable depends on the content and scale of the work. We will confirm the property during the investigation phase and incorporate necessary procedures into the process. |
| Material Delivery and Scaffolding | In busy roads around Hashimoto Station and on slopes or narrow roads in mountainous areas, there are sites where large vehicles cannot access, and consideration for delivery times is necessary. Our in-house 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. |
| Parking During Construction | Vehicles on the side where scaffolding will be erected need to be temporarily moved. In buildings with many units or those with on-site parking, it may take time to secure the number of vehicles, their arrangement, and relocation. We will coordinate arrangements, including the availability of nearby coin parking and monthly rentals, starting 2 to 3 months before construction begins. |
| Flood, Internal Water, and Landslide Risk Assessment | The risk of flooding and internal water varies by property in low-lying areas along rivers, while landslide risks differ in mountainous areas and slopes. We will check the property’s risk on the hazard map and assess waterproofing and protection around the first floor, basement, mechanical rooms, external piping, and electrical equipment, as well as the condition of retaining walls and slopes during the site investigation. Necessary ranges will be clearly stated in the estimate. |
| Consideration for Neighbors | In residential areas, near stations, or close to factories, high-pressure washing splatter, paint odors, and noise from material deliveries may reach nearby residents. We strictly adhere to greeting rounds, posting schedules, and adhering to working hours. In buildings with many units, we also provide notifications through management associations or neighborhood councils. |
| Notifications to Residents | The elderly population ratio in Midori Ward is 30.1% (as of January 1, Reiwa 8), and it was reported as the highest ward in the city in 2019. Since the overall figures for the ward vary by building in terms of resident composition and times at home, we will provide notifications both in distribution and on bulletin boards, and requests for clearing balconies and confirming residents will be conducted after checking their availability in advance. |
* Kakeru Koumuten has five locations, including a showroom and material storage, in Yokohama City, and we respond to consultations throughout all of Midori Ward, including Hashimoto, Aihara, Shiroyama, Tsukui, Sagamiko, and Fujino.
Signs of Deterioration Requiring Large-Scale Repairs and Timing
Generally, large-scale repairs are estimated to occur every 12 to 15 years. According to a survey by the Ministry of Land, Infrastructure, Transport and Tourism, the actual repair cycle is most commonly 13 years, with about 70% falling within the 12 to 15 year range, and the cycle tends to shorten with each occurrence. However, the actual judgment is based on the condition of deterioration rather than the number of years, so if symptoms like those listed below are observed, we recommend an early on-site investigation.
| Location | Dangerous Signs of Deterioration if Left Untreated | Main Actions |
|---|---|---|
| Exterior Wall (Painted Surface) | Chalking (white powder on hands), fading, cracks wider than 0.3mm, blistering or peeling of paint | Substrate repair + exterior wall painting |
| Exterior Wall (Tile Surface) | Tile lifting or falling off, missing grout, efflorescence, hollow sound when tapped | Injection for lifting, replacement, clear waterproofing |
| Sealing | Cracks in joints, shrinkage, peeling, hardening | Re-sealing |
| Rooftop/Balcony | Bubbling or breaking of waterproof layer, puddles, clogged drains, 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, shifted 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 |
| Common Hallway/Staircase Floor | Lifting or peeling of long sheet, opening at edges, exposed substrate | Replacement of long sheet + substrate waterproofing |
Repair Cycle Guidelines by Location (Ministry of Land, Infrastructure, Transport and Tourism Guidelines)
| Location/Work | Estimated Cycle | Location/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 | Drainage 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 “Long-Term Repair Plan Creation Guidelines” (Revised June 2024, PDF) / Ministry of Land, Infrastructure, Transport and Tourism “Fiscal Year 2021 Survey on Large-Scale Repair Work for Condominiums”
Examples of Large-Scale Renovation Work
This is an example of exterior renovation work on a mixed-use building undertaken by Kakeru Koumuten. The building had leaks occurring from several locations, and we combined clear waterproofing for the tile exterior wall 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 tile replacement / Painting of ancillary parts (pipes, drip edges) / Roof waterproofing (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 ancillary parts: Radical silicone paint / Roof 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 roof, 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
Process from On-Site Investigation to Completion
From inquiry to completion 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.
- 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 Midori Ward, we will also check for rust on iron parts, potential flooding, internal water issues, and landslide risks, as well as the condition of slopes and retaining walls, and confirm the delivery route 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 boards, and trial painting. For management associations, we can assist in preparing materials for general meetings. In areas subject to district planning, landscape planning, or building agreements, we will also explain the procedures and color considerations.
- Notification to Residents & Neighbors We will distribute construction notifications, visit neighbors to introduce ourselves, and set up a bulletin board at the entrance (for project schedules 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 and tile repair → waterproofing → iron parts and ancillary work in that order. A supervisor will inspect and take construction photos at each stage.
- Completion Inspection, Scaffolding Dismantling & Handover We will confirm the finished work 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 annual DM notifications, and inspections can be conducted every year. Simple repairs such as partial sealing are provided free of charge.
Resident Communication, Additional Work Approval, Inspection Reports
Equally important as the construction itself is “when, what, and with what materials we report”. At Kakeru Koumuten, we provide materials and reports in the following four situations.
| 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 work scope. |
| Before Construction to During Construction Notification to Residents & Neighbors |
We will distribute construction notifications, visit neighbors to introduce ourselves, and provide project schedules and laundry information on the entrance bulletin board. |
| During Construction Approval for Additional Work |
Deterioration discovered after scaffolding is set up will be addressed by presenting photos, quantities, and costs for approval before proceeding with the work. |
| During Construction to Completion Inspection Reports |
A supervisor will inspect each stage and take construction photos. Upon completion, we will confirm the finished work 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
Large-scale repairs are principally carried out while residents remain in their homes. However, there will be some restrictions on daily life while scaffolding is in place. Most troubles can be prevented by providing advance notice, so Kakeru Koumuten Co., Ltd. thoroughly explains and posts information before construction begins.
| Impacts | What Actually Happens / Our Response |
|---|---|
| Laundry | On days of high-pressure washing, painting, and waterproofing, outdoor drying is not 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 days as possible for drying. |
| Window Opening and Closing | In addition to washing and painting days, there may be times when windows cannot be opened due to protective measures, drying, and waterproofing work. We will provide information for each phase, so please check the postings and notifications. We will schedule the work to avoid continuous closures. |
| Balcony | During floor waterproofing and handrail painting, we ask for temporary relocation of personal items, potted plants, and air conditioning outdoor units. The timing will be notified in advance for each household. |
| Noise and Odor | The period of substrate repair (chipping and drilling) will produce 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 a potential 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 conduct. |
| Parking | Vehicles on the side where scaffolding will be erected will need to be temporarily relocated. Since securing a new parking spot may take time, we will work together to secure a relocation spot 2 to 3 months before construction starts. |
| Pets, Small Children, and Working from Home | If you have sensitivities to noise, please let us know in advance, and we may be able to adjust the work schedule accordingly. Please feel free to ask. |
| Rented Rooms | We assist owners in creating notification documents for residents. If there are concerns about the impact of construction on occupancy rates, we can also suggest a change of image with color simulations. |
How to Choose a Large-Scale Repair Contractor and Ordering Method
There are many large-scale repair contractors that cover Midori Ward in 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
● Confirm the presence of warranties and aftercare services
● Obtain estimates from multiple contractors (at least 3 companies)
● Confirm whether they are self-managed
Extensive Experience in Large-Scale Repairs
Large-scale repair contractors often have websites that showcase their exterior renovation achievements. If they provide detailed explanations of repair contents with photos, it gives peace of mind as it can serve as a reference when you actually request work.
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. 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 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 construction, having a leak warranty from the contractor ensures that repairs can be made at no cost, providing peace of mind! A company that offers a warranty demonstrates confidence in their work, which can serve as 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 a leak warranty. Some contractors also offer aftercare services separate from warranties, so be sure to check for warranties and aftercare services.
At Kakeru Koumuten, we send 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 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 painting,” and “confirmation of the process.” Carefully compare these details! If the quality of auxiliary materials is low or if processes 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, ensure that the repair methods are appropriate for the condition of the substrate!
Check these points on the estimate (checklist)
| Check Items | Points to Consider |
|---|---|
| Is there an excessive use of “lump sum” notation? | Are the quantities and unit prices clearly stated? With “Exterior Wall Repair Lump Sum,” comparison and verification are not possible. |
| 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 FY2021, the average is about 10% of the construction cost (excluding common temporary costs), but this varies depending on the size and conditions of the building, so there is no uniform standard. |
| Are the names of materials listed? | Are the manufacturer names, product names, grades, and number of coats for paints and waterproofing materials specified? |
| Treatment of quantities for substrate repairs | This is an item that cannot be accurately measured until scaffolding is set up. It is crucial to specify whether it is “estimated quantity” or “actual quantity settlement,” and the agreements regarding increases or decreases. |
| Warranties and after-inspection | Warranty period for each construction, frequency of inspections, and scope of free support. |
| Company backing | Type of construction industry license, track record of similar scale and structure projects, presence of qualified personnel. |
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 vary depending on the actual deterioration condition and customer preferences.
There are cases where contractors that completely outsource to subcontractors lack knowledge and experience, leading to proposals for repairs in irrelevant areas or unnecessary work. If you request a subcontractor after investigation, it may incur additional time and costs. By managing in-house with knowledge and experience, responsible construction that keeps costs down becomes possible.
Furthermore, contractors that outsource to subcontractors may also have delayed responses in case of any troubles during construction. It is safer to avoid having a company that has not actually met with the customer manage the construction. Kakeru Koumuten performs everything from temporary scaffolding setup to exterior wall painting and waterproofing work in-house, with knowledgeable and experienced personnel managing the construction!
There are three ordering methods. The choice affects the approach.
Especially for management associations, it is necessary to decide “how to request” before “which company to hire.” The main ordering methods are the following three.
| Method | Procedure | Advantages | Disadvantages |
|---|---|---|---|
| Responsible 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) / A single point of contact reduces the burden on the management association / Responsibility is clearly defined / The period until ordering can sometimes be shortened. | Specifications can become reliant on the construction company, making it difficult to compare side by side / Independent third-party checks are hard to implement, 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 different company handles the construction. | Allows for comparison of construction companies under the same conditions / Independent supervision during construction. | Consulting fees are required separately / Caution is needed regarding conflicts of interest and collusion risks / The period can easily become prolonged. |
| Management Company Prime Contract Method | The management company acts as the prime contractor, with subcontractors performing the construction. | Easy coordination with daily management / Minimal effort required from the management association. | Can become expensive due to intermediate margins / Competition principles may not be effectively applied. |
Collusion and Inappropriate Consulting Issues in Large-Scale Renovations and Self-Defense Measures
Latest 2026 In the large-scale renovation industry, inappropriate orders linked between design consultants and construction companies have long been a problem. The Ministry of Land, Infrastructure, Transport and Tourism issued warnings and notifications to management associations in January 2017 and April 2023, and on September 28, 2026, the Japan Fair Trade Commission announced that it had issued exclusion orders to 38 companies and a total of 1.63788 billion yen in payment orders to 37 companies regarding large-scale renovation work commissioned by condominium management associations in the Kanto region.
※Based on the announcement by the Japan Fair Trade Commission (September 28, 2026).
Three Typical Methods
① Dummy Estimates
Prior to placing an order, companies decide on a contractor, while other companies only provide a formal high estimate, creating a “fixed race.” This makes it appear to the management association that they have properly obtained competitive estimates.
② Collusion with Design Supervisors
Consultants contract at extremely low design supervision fees while receiving kickbacks from the high construction costs of their partner contractors. Be cautious of design supervision fees that are too low.
③ Back Margin
A certain percentage of the contract amount is given as a kickback, which is added to the construction costs as an expense. As a result, the management association ends up paying more.
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 Repairs in Midori Ward, Sagamihara City
- How much does large-scale repair in Midori Ward, Sagamihara City cost?
- For condominiums, according to the Ministry of Land, Infrastructure, Transport and Tourism’s fiscal year 2021 survey, about 70% fall within the range of 750,000 to 1,500,000 yen (excluding consumption tax and common temporary 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. Costs vary depending on the condition of the substrate and whether waterproofing or roofing work is required, so we provide free on-site estimates.
- How often should large-scale repairs be conducted?
- Generally, a cycle of 12 to 15 years is recommended, and the actual cycle is most commonly 13 years according to the Ministry of Land, Infrastructure, Transport and Tourism’s survey, with about 70% falling within the 12 to 15-year range. However, the determining factor is not the number of years but the condition of deterioration. If there are signs of deterioration in the sealing, floating tiles, or ruptured waterproof layers, it is advisable to carry out repairs without waiting for the cycle, as this can ultimately reduce costs. For older buildings, the proportion of tile repairs and iron part replacements tends to increase in the second and third rounds of repairs.
- How long does the construction period take? Can residents stay during the work?
- For apartments, the period is typically 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 ensure to minimize the impact on daily life by 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, conducting building diagnostics, selecting contractors, and passing resolutions at general meetings, followed by 3 to 6 months for construction. Overall, it is advisable to plan for about 2 years to proceed comfortably. If you are utilizing subsidies or tax incentives, please also factor in the time needed to obtain management plan certification (resolutions at general meetings, prior confirmations, and applications to the city).
- Are there any subsidies available for large-scale repairs in Midori Ward, Sagamihara City?
- The list of housing assistance and subsidy programs in Sagamihara City does not include subsidies specifically for large-scale repair work on condominiums (Kanagawa Prefecture also does not provide subsidies for the work itself). However, for condominium owners, if certain conditions are met, a 50% reduction in fixed property tax can be applied under the “Condominium Longevity Promotion Tax System.” Additionally, Sagamihara City offers free consultation services and advisor dispatch, subsidies for seismic diagnostics and seismic renovation plans for condominiums built to old seismic standards, and incentives for introducing residential smart energy equipment (confirmation with the city is necessary to determine if common areas are eligible). If the work includes windows and insulation, there may be eligibility for “Advanced Window Renovation 2026” and “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 tax can be reduced through large-scale repairs. Is that true?
- If certain conditions are met, it is true. Under the Condominium Longevity Promotion Tax System, if a condominium that is over 20 years old and has more than 10 units conducts large-scale repairs (such as exterior painting, floor waterproofing, and roof waterproofing) that contribute to its longevity, the fixed property tax for the following year 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 Tax Division within three months of completion. For certified management plan condominiums, there are additional requirements such as raising repair reserve funds, so it is recommended to start preparations more than a year in advance.
- Are there any changes to subsidies starting from the fiscal year 2026?
- Yes, there are. 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” began accepting bulk applications for apartment buildings starting May 29, 2026 (the application process will be handled by registered contractors). Please be careful not to base your financial plans on outdated information.
If you are looking for a large-scale repair contractor in Midori Ward, Sagamihara City, contact Kakeru Koumuten Co., Ltd.
We handle many exterior wall renovations and large-scale repairs for condominiums and apartments in Midori Ward, Sagamihara 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 long with one renovation” “I want to keep costs down as much as possible” “I want to improve insulation performance because the indoors are hot” We will propose the best solutions for your specific requests and future repair plans.
From temporary scaffolding work to roofing and exterior 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 estimates!
On-site surveys, estimates, and color simulations are all free of charge
Please feel free to contact us via the inquiry form, phone, or LINE.
It’s perfectly fine to just present estimates from other companies.
Large-Scale Repair Work Service Area
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
Aihara / Aone / Aonohara / Aoyama / Tai / Oshima / Oyama Town / Ogura / Obara / Obuchi / Kamikuzawa / Kawajiri / Kubozawa / Sanogawa / Sawai / Shimokuzawa / Shiroyama / Sunzawarashi / Tana / Tanigahara / Chigira / Toriya / Nakazawa / Nakano / Nagatake / Nagura / Nishihashimoto / Nihonmatsu / Negoya / Hashimotodai / Hashimoto / Hayamajima / Harajuku Minami / Harajuku / Higashihashimoto / Hiyori / Hirota / Makino / Matano / Machiya / Mitsui / Mikage / Mukohara / Motohashimoto Town / Yoshino / Yosese / Yosese Motomachi / Wakabadai / Wakayanagi
・When should large-scale renovations be carried out? An explanation of the optimal timing and risks of postponement!
・Estimates are essential when carrying out large-scale renovations! Key comparison points and precautions!
・5 common troubles in large-scale renovations of condominiums! A thorough explanation of causes and prevention measures!
・What is waterproofing work in large-scale renovations? A thorough explanation of roles, signs of deterioration, and precautions!
・Not enough funds for large-scale renovations… An explanation of how to deal with funding shortages and preparations you can do right now!
・What is substrate repair in large-scale renovations? A thorough explanation of necessary reasons, signs of deterioration, and types of work!
・What is sealing work in large-scale renovations? An introduction to roles, methods, and tips for avoiding mistakes!
・What is tile repair in large-scale renovations? An explanation of signs of deterioration, types of work, and cost averages!
・What is exterior wall painting in large-scale renovations? A thorough explanation of necessity, signs of deterioration, and cost averages!
・For exterior renovations in Midori Ward, Sagamihara City, trust Kakeru Koumuten!
・For roof renovations in Midori Ward, Sagamihara City, trust Kakeru Koumuten!
・Leave your exterior wall painting in Midori Ward, Sagamihara City to Kakeru Koumuten Co., Ltd.!
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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!
