Leave the installation of solar panels in Ashigarakami District, Kanagawa Prefecture (Nakai Town, Oi Town, Matsuda Town, Yamakita Town, Kaisei Town) to Kakeru Koumuten Co., Ltd.!
For
Solar Panel and Storage Battery Installation in
Ashigarakami District, Kanagawa Prefecture, trust
Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted withsolar panel and storage battery installations considering roofs and waterproofing!
“How to Choose a Solar Panel Contractor in Ashigarakami District”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Ashigarakami District”
We will also explain the above three points!
Installing solar panels carries risks such as“the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtainingthree or so estimates!
Table of Contents (Tap to Open/Close)
- Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Ashigarakami District, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Possible Subsidies and Grants Available in Ashigarakami District
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Ashigarakami District, Kanagawa Prefecture
- Benefits of Introducing Solar Equipment
- Points to Consider When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions about Solar and Storage Battery Installation in Ashigarakami District
- If You’re Looking for a Solar Panel Installation Contractor in Ashigarakami District, Contact Kakeru Koumuten
- Characteristics of Ashigarakami District, Kanagawa Prefecture, and Points for Solar Installation
- Service Area in Ashigarakami District, Kanagawa Prefecture
Reasons Kakeru Koumuten is Chosen for Solar Panel Installation in Ashigarakami District, Kanagawa Prefecture
The reasons our company is entrusted with solar panel installation by customers in Ashigarakami District, Kanagawa Prefecture include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Problems such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and trouble after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent issues after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar and exterior renovation work.
We have established five bases centered in Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Ownership of Scaffolding Materials
To ensure safety during work on the roof, we own the necessary scaffolding materials for temporary scaffolding based on construction conditions and can assemble scaffolding ourselves.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs on scaffolding work.
We have scaffolding materials for approximately 50 single-family homes!
Even in the Ashigarakami District, where residential areas spread from the Ashigara Plain to hilly and mountainous areas, our own scaffolding team will plan the scaffolding according to the site.
Storage of materials in our large warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, we canpurchase materials at a lower cost!
Additionally, since we always have stock of roofing materials, we can provideswift responses in emergencies!
Sorting and transporting waste materials in-house
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are installed on the roofing materials!
It is also possible to simulate the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany each other, we also provide samples of roofing materials and models that show the structure, allowing for detailed explanations!
3.All Work Performed by Our Own Team
One of Kakeru Koumuten’s major strengths is all work performed by our own team.
By having a consistent system from inquiry to project completion, Kakeru Koumuten can provide high-quality roof remodeling 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’s the sales representative or construction management, smooth communication is possible.
We can perform consistent in-house work from temporary scaffolding installation to exterior wall painting and roof remodeling!
4. 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 workers and painting technicians, and we are confident in our construction techniques.
We can also handle large-scale roofing projects such as factories!
5. Warranty and Aftercare
In addition to the manufacturer’s warranty, our solar panel installation work comes with our own workmanship warranty (leakage warranty)!
(The workmanship warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty without performing roof renovations. The workmanship warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary based on the warranty content.)
Aftercare maintenance is available annually, and we send out notification DM each year.
If you have any questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roof troubles and situations.
Even if you cannot access the roof at high altitudes, we can respond using a drone!
During leakage investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of the solar panels decreases due to dirt, we can also provide cleaning with a specialized brush.
We will respond according to your preferences.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly provide technical training so that each staff member can respond to various cases.
8. Creation of Easy-to-Understand Materials and Simulations
At Kakeru Koumuten Co., Ltd., in addition to “estimates”, “layout diagrams”, and “power generation simulations”, we also provide a “solar installation guidebook” and a “profit and loss simulation” that takes into account loan interest rates and electricity costs.
The profit and loss simulation can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar installations can easily understand the materials we provide, which include important points and potential drawbacks!
We encourage you to obtain comparative estimates and review plans from other companies!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 to 30 years.
It is crucial to confirm “whether it is safe to install them directly on the current roof” before installation, as this is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, specializing in roofing work, has summarized the items to check before installation.
| 1. Type of roofing material and age | The method of securing the panels varies depending on the roofing material, such as slate, tiles, metal roofs, or flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of the substrate and waterproof sheet | If the sheathing or roofing (waterproof sheet) beneath the roofing material is damaged, it can affect the fastening strength and waterproofing. We also check for any signs of leaks. |
| 3. Orientation, slope, and shadows of the roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, can affect power generation. We create a layout diagram from the drawings and the site, and you can check the power generation simulation. |
| 4. Shape of the roof and installable area | The number of panels that can be installed (installation capacity) is determined by the shape and size of the roof. The number of panels that can be installed varies depending on their size, so we compare based on the total output of the roof. |
| 5. Method of securing and waterproofing details | We check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fastening method varies by technique, so please confirm the waterproofing treatment of the fastening parts at the time of estimation. |
| 6. Weight of the roof | The roof will become heavier due to the added weight of the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may also be an option if necessary. |
| 7. Location of equipment installation and wiring | We confirm the installation locations for the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring also affects costs. |
Securing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (such as fixing brackets to the roof material and substrate with screws) | Waterproof treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay (cover method) or replacement first. |
| Tile Roof | Fixed with brackets and methods suited to the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing around the frame. Consider in conjunction with the timing of waterproofing work. |
If you carry out roof renovations 10 to 20 years after installation, there will be additional costs for the removal and reinstallation of solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten Co., Ltd. specializes in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Ashigarakami District, Kanagawa Prefecture
PotentialSubsidies and Grants in Ashigarakami District, Kanagawa Prefecture
When introducing solar panels or storage batteries in Ashigarakami District (Nakai Town, Oi Town, Matsuda Town, Yamakita Town, Kaisei Town), there is a possibility of being eligible for the systems of “the national government,” “Kanagawa Prefecture,” and “Nakai Town, Oi Town, Matsuda Town, Kaisei Town.”
The following information is based on the official pages of each system as of October 6, 2026. The application status may change depending on the budget and recruitment period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Period for Subsidy Programs
| System | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Nakaitown “Subsidy for Home Solar Power Systems, HEMS, and Battery Installation” | Individuals installing in their own homes within the town, who have a lighting contract and no tax arrears. Must apply to the Nakai Eco Monitor and be able to cooperate with a one-year report. Application must be made before installation/start of construction (for battery only, it must be installed in connection with the solar power system) | Solar: 15,000 JPY per kW (up to 52,000 JPY) HEMS: 10,000 JPY (fixed amount) Battery: 50,000 JPY (fixed amount) |
Applications accepted in order of submission (in-person only). May close due to budget constraints. Performance reports are due by March 19, 2027 |
| Oitown “Subsidy for Residential Smart Energy Equipment Installation Costs” | Individuals residing (including planned) in the town with a lighting contract and no tax arrears. Must be the property owner or have written consent from the owner. Installation must occur after receiving the grant approval notification | Solar: 20,000 JPY per kW (up to 100,000 JPY) HEMS: 20,000 JPY (fixed amount) Battery: 50,000 JPY (fixed amount) |
From April 1, 2026, on a first-come, first-served basis. According to the town’s announcement (as of August 1, 2026), there are plans for 30 solar, 20 HEMS, and 20 battery installations, with remaining slots being less than 10 for solar and HEMS, and less than 5 for batteries |
| Matsudatown “Smart House Development Promotion Project Subsidy System” | Individuals with a lighting contract who will install in their own residence within the fiscal year. Conditions include the owner’s consent and payment of town taxes, with leasing and PPA installations also eligible. Application is required before construction starts | Solar: 20,000 JPY per kW (up to 100,000 JPY) Battery: 50,000 JPY (fixed amount) HEMS: 10,000 JPY (fixed amount), etc. |
First-come, first-served within the budget of 3,750,000 JPY for the fiscal year 2026 (mail applications not accepted). Performance reports are due within 30 days of installation completion or by March 15, 2027, whichever comes first |
| Kaiseitown “Zero Carbon City Creation Subsidy System” (Subsidy for Smart House Renovation of Existing Homes) | Existing homes in the town that are over one year old are eligible. Conditions include consuming more than 30% of the generated electricity on-site and not using the FIT system | Solar: Up to 120,000 JPY per kW (for priority measures acceleration subsidy, up to 4 kW. Over 4 kW is 70,000 JPY/kW), otherwise 50,000 JPY/kW (up to 200,000 JPY) Batteries, HEMS, and additional installation of three or more systems are also eligible (please check the town’s materials for details) |
Recruitment starts on July 1, 2026. Application deadline is February 15, 2027 (for priority measures acceleration subsidy, March 15). This is a limited-time system until the fiscal year 2026 |
| Yamakitatown | The town’s official website does not confirm any unique subsidy system for solar power or batteries for residential use | (There may be applicable programs from Kanagawa Prefecture or the national government) | Please contact Yamakita Town for the latest information |
| Kanagawa Prefecture “Reiwa 8 Annual Kanagawa Prefecture Subsidy for Residential Solar Power Generation and Storage Battery Installation Costs” | Install solar power generation and storage batteries in a residential building or apartment that ensures seismic performance within the prefecture. Applications must be made by the individual, and construction can begin after the grant decision. | Solar Power: 70,000 JPY/kW Storage Battery: 150,000 JPY/unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 has reached its application deadline. Please check the prefecture’s official page for future applications. |
| National “DR Home Storage Battery Project” (Reiwa 7 Annual Supplement) | Newly install a home storage battery system that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 30% and a maximum of 600,000 JPY per application). | The budget was reached on May 29, 2026, and the public recruitment has ended (applications are currently not possible). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential work such as insulation renovation of windows (openings) and the structure; applications cannot be made for just the installation of storage batteries. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Reiwa 8 Annual Kanagawa Prefecture Subsidy for Self-Consumption Type Renewable Energy Installation Costs” | Corporations and individual business owners filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar Power: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Recruitment ended on September 3, 2026 (application amount reached the budget amount). |
As of October 6, 2026, the subsidies in Oi Town have only a few remaining planned cases, and the residential subsidies in Kanagawa Prefecture have passed the application deadline for Phase 2 of Reiwa 8, while the national DR home storage battery project has also ended its public recruitment. Subsidies in Nakai Town, Oi Town, and Matsuda Town require applications before construction starts (or installation after grant approval), and the prefectural residential subsidies require construction to begin after receiving “grant decision”. Starting construction beforehand may result in ineligibility, and applying does not guarantee a grant, so please confirm before contracting or starting construction.
Kakeru Koumuten Co., Ltd. will guide you on eligibility conditions for each program after confirming them.
Nakai Town “Subsidy for Home Solar Power Generation Systems, HEMS, and Storage Battery Installation”
Nakai Town provides subsidies for individuals installing solar power generation systems, HEMS, and storage batteries in their own residences within the town. Conditions include having a lighting contract and no delinquency on town taxes, as well as being able to cooperate with a year’s worth of reporting after applying to the Nakai Eco Monitor (environmental household account monitor). If only a storage battery is installed, it must be connected to the solar power generation system.
The subsidy amount for the fiscal year Reiwa 8 is 15,000 yen per kW for solar power (maximum 52,000 yen), 10,000 yen for HEMS, and 50,000 yen for storage batteries. This system accepts applications in the order they are received, and items that have already been installed or purchased, or projects that have already started are not eligible. Due to budget constraints, the application may close, so please check the town’s official page for the status of applications.
👉 Click here for Nakai Town’s official page
Oi Town “Subsidy for Residential Smart Energy Equipment Installation Costs”
Oi Town provides subsidies for individuals residing (or planning to reside, with resident registration at the time of subsidy completion) in the town for the installation costs of residential smart energy equipment. Conditions include having a lighting contract, the building being for residential use, obtaining the owner’s consent, and no delinquency in town taxes.
The subsidy amount for the fiscal year Reiwa 8 is 20,000 yen per kW for solar power (maximum 100,000 yen), 20,000 yen for HEMS, and 50,000 yen for storage batteries. Applications are accepted on a first-come, first-served basis starting from April 1, 2026, and as of the town’s announcement (as of August 1, 2026), there are fewer than 10 remaining for solar power and HEMS, and fewer than 5 remaining for storage batteries. You must install after receiving the subsidy approval notification, so please check the latest application status on the town’s official page.
👉 Click here for Oi Town’s official page
Matsuda Town “Smart House Development Promotion Project Subsidy System”
Matsuda Town has established a subsidy system for individuals who install eligible equipment in their own residences within the fiscal year. Conditions include having a lighting contract, obtaining the owner’s consent, and paying town taxes, with installations via lease or PPA also being eligible.
The subsidy amount for the fiscal year Reiwa 8 is 20,000 yen per kW for solar power (maximum 100,000 yen), 50,000 yen for stationary lithium-ion storage batteries, and also includes HEMS (10,000 yen), home fuel cells, water heaters, V2H charging equipment, etc. The budget for the fiscal year Reiwa 8 is 3,750,000 yen, and applications are accepted on a first-come, first-served basis (mail applications are not accepted), with applications required before starting construction. Performance reports must be submitted within 30 days of installation completion or by March 15, 2027, whichever comes first.
👉 Click here for Matsuda Town’s official page
Kaisei Town “Zero Carbon City Creation Subsidy System” (Subsidy for Smart House Renovation of Existing Homes)
Kaisei Town has established a subsidy system for installing solar power systems, storage batteries, HEMS, etc., in existing homes in the town that are over one year old, aiming for the realization of a zero-carbon city. Conditions for solar power include consuming more than 30% of the generated electricity for self-use and not using the FIT system.
According to town documents, solar power generation is up to 120,000 yen per 1kW (for the priority measures acceleration subsidy, up to 4kW; over 4kW is 70,000 yen/kW), while other installations are 50,000 yen/kW (with a cap of 200,000 yen). There are also additional allowances for installing storage batteries, HEMS, and three or more devices simultaneously. Applications for the Reiwa 8 fiscal year will begin on July 1, with a deadline of February 15, 2027 (for subsidies other than the priority measures acceleration subsidy, the deadline is March 15). This program is limited to the Reiwa 8 fiscal year.
👉 Click here for the official page of Kaisei Town
Yamakita Town
Regarding Yamakita Town, the town’s official website does not confirm any unique subsidy system for residential solar power generation or storage batteries. There may be programs available from Kanagawa Prefecture or the national government, so please contact Yamakita Town for the latest information and consultations.
National Subsidy “DR Home Storage Battery Project (Support Project for Home Storage Systems for DR Resource Introduction)”
The national government has been implementing the “DR Home Storage Battery Project” to support the installation of home storage batteries.
This program targets those who are introducing new storage systems that can be utilized for demand response (DR) with registered products. In the fiscal year 2027 supplementary budget, the subsidy amount was based on an initial effective capacity of 34,500 yen per 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are conditions such as excluding contracts or orders made before the grant decision.
However, the fiscal year 2027 supplementary budget reached its application limit on May 29, 2026, and the public offering has ended (the previous fiscal year 2026 supplementary budget also ended on July 2, 2025). Applications are currently not possible, so please check the official website for future public offerings.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Storage Battery Project
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy”
Kanagawa Prefecture provides subsidies for those who install both “solar panels” and “storage batteries” in residential properties.
The subsidy details are 70,000 yen per 1kW of solar power generation output and 150,000 yen per storage system.
For example, if you install a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction begins before the grant decision, it will not be eligible, and the application must be made by the individual (applications by contractors on behalf are not permitted). The residential property must also meet seismic performance standards. The compatibility of this subsidy with other subsidy programs may vary, so please be sure to check.
For the fiscal year 2026, the first application period (May 11 to June 30) and the second application period (September 7 to September 30, first-come-first-served) have been conducted, and the second period has reached its application deadline. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Here is the official page of Kanagawa Prefecture
Kanagawa Prefecture “Subsidy for Introducing Self-Consumption Type Renewable Energy for Fiscal Year 2026” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses that introduce “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include that the solar power generation must have an output of 10kW or more, supply power to business facilities within the prefecture, and not be equipment certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen).
As the application amount reached the budget amount for fiscal year 2026, the recruitment was closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Ashigarakami District are advised to check the official page of Kanagawa Prefecture for the next recruitment.
👉 For more details, click here
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu | Click here for costs related to Solar Panel Removal and Hot Water Heater Dismantling
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be confirmed by separating them into “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Solar Panel Installation Set,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Understanding Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared based on the amount of electricity they can store, expressed in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel costs as approximately 800,000 JPY to 1,200,000 JPY for 3 to 5 kW, and 1,200,000 JPY to 1,900,000 JPY for 6 to 10 kW. (These are only approximate amounts and may vary based on wiring length, scaffolding area, existing roofing materials, panel layout, etc.)
▶ Service Menu | Click here for costs related to Solar Panel Installation and Storage Battery Installation
Items to Confirm in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment by only looking at the amounts. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) are listed. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls the battery together. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (whole house or specific circuits), installation location. |
| 4. Mounting Frame and Fittings | Name of fittings suitable for roofing materials and method of fixing (whether it is a method that drills holes or a method that clamps and fixes). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, presence of a monitor to check power generation. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at fixing points, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Application | How much support is included for applications to the power company, certification application for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If roofing work and exterior painting are done simultaneously, check that the same scope and quantity are not counted twice. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters or old panels and disposal costs for waste materials are included. |
| 10. Tax Classification and Warranty | Whether it is tax-inclusive or tax-excluded, conditions under which additional costs may arise, details and duration of manufacturer warranty and workmanship warranty. |
If the capacity is different, the price and power generation will also change. Kakeru Koumuten Co., Ltd. welcome competitive quotes, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit and Loss Simulator for Solar Power Generation
With the above simulator,
you can obtain an estimated quote and a profit and loss simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can obtain an estimated quote and profit and loss simulation!
*The simulation results are estimates. Actual profit and loss may vary depending on conditions such as electricity rates, self-consumption ratio, selling price of electricity, and costs for equipment inspection or replacement.
Customer Feedback
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Examples of Solar Panel Installation
| Work Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufacturing / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch-type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| Approximately 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the introduction of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels when placed on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of grants to be provided, and we explained this to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Ashigarakami District, Kanagawa Prefecture
There are many solar panel installation contractors available in Ashigarakami District, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery storage installation work, make sure to check the following 4 points.
● Have extensive knowledge not only about solar panels but also about roofs
● Confirm the presence of warranties and after-sales maintenance
● Obtain estimates from multiple contractors (3 companies is a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Have knowledge not only about solar panels but also about roofs
Improper installation of solar panels can sometimes be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels were installed on a severely deteriorated roof, resulting in leaks
・Solar panels were installed on a roof with a short lifespan, necessitating remodeling to detach and reattach the solar panels within a few years
・Misjudgment of the type of waterproofing led to incorrect processing, causing leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unforeseen troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the presence of warranties and after-sales maintenance
When choosing a solar installation contractor, make sure to check for the presence of warranties. It is important to confirm not only the number of years but also the coverage, disclaimers, and cost conditions.
While the solar panels and battery storage units come with manufacturer warranties, also check for the presence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond under the warranty if it falls within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from the warranty, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof can occur in areas that are not visible, so there is a possibility that customers may not notice them.
By conducting inspections of these hidden areas during after-sales maintenance, it becomes easier to detect anomalies early, preventing major repairs or breakdowns!
Kakeru Koumuten Co., Ltd. provides a rain leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, it may not be possible to provide a warranty without performing roof renovations.)
We also conduct after-sales maintenance and send out DM every year!
Please check the DM, and if you wish, we will visit for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request from your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates,
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-sales services”
and make detailed comparisons to make your judgment! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ To “Breakdown of Installation Capacity, Equipment, and Construction Costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where contractors cannot apply on behalf of the client, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the grant will be issued after a review! (The flow of procedures varies by system)
▶ To “Subsidies and Grants That May Be Applicable in Ashigarakami District” within this Article
Benefits of Introducing Solar Power Systems
The benefits of introducing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantage
The biggest advantage of introducing solar panels is the economic benefit!
While the selling price of electricity has decreased compared to 10 years ago, you can benefit by reducing the amount of electricity you purchase from the utility company by consuming the electricity you generate!
As electricity costs rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential use (less than 10kW), the selling price (FIT) from October 2025 onwards is set at “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply for the 2026 fiscal year. After the 5th year, it is often more advantageous to use the electricity at home (self-consumption), making the combination with a storage battery a viable option.
👉 Ministry of Economy, Trade and Industry | For purchase prices and periods, click here
Benefit 2: You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, you may be able to utilize subsidies!
Reducing the actual burden amount through subsidies is a significant advantage!
In Ashigarakami District, there may be systems available from the national government, Kanagawa Prefecture, and each town. Since the application status and order differ by town, please check the official pages of each town.
Benefit 3 : Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and reduces dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly method of power generation. (However, devices like power conditioners may have operational noise.)
Benefit 4 <strong: Heat Insulation Effect is Expected!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, this can help reduce the temperature rise of the roof, providing expected heat insulation effects!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5: Electricity can be used even during power outages!
If a storage battery is installed, it becomes possible to use electricity even during emergencies like power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capabilities, you may be able to use electricity from a dedicated outlet during daytime generation.
(Note that the devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1: Maintenance costs can be incurred
A particularly overlooked maintenance cost is for the roof where solar panels are installed.
If you perform roof renovations 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorated, it is reassuring to renovate it with durable roofing materials before installing solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It would be reassuring to ask for a simulation that considers maintenance costs before introducing solar panels!
Point 2: The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when using screws or other fasteners to secure the roofing material and substrate, waterproofing of the fixed parts becomes crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and fasteners, and it cannot be used with all metal roofs.)
Base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, replacing it with a lightweight roof may also be an option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
How to Choose 1: Compare based on total output of the roof
When installing solar panels on the roof, it is important to know how much electricity can be generated in a limited area, and the more electricity generated, the better!
Solar panels come in various sizes and outputs depending on the manufacturer.
For example, a 350W output panel and a 400W output panel may seem that the higher output panel is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different numbers of panels that can be installed on the same roof due to size differences.
400W×15 panels = 6kW (total output of the roof)
350W×20 panels = 7kW (total output of the roof)
As shown above, even if the output of a single panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual electricity generation (kWh) will vary depending on conditions such as the roof’s orientation, slope, and shading.
How to Choose 2: Compare based on degradation rate of solar panels
Solar panels have a degradation rate, and their output gradually decreases over 10 or 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or electricity generation itself.
By not deciding solely based on initial output and considering the degradation rate, you can choose solar panels without regrets!
How to Choose 3: Compare based on warranty period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
Regarding the output warranty, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
It’s always better to have a longer warranty, so let’s check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Ashigarakami District
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Ashigarakami District. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Ashigarakami District, Kanagawa Prefecture?
The cost varies depending on the installation capacity, equipment, and roof condition. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines by capacity are available on the solar panel installation and storage battery installation pricing page. We will create a layout diagram from the drawings and site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Ashigarakami District?
As of October 6, 2026, Nakai Town, Oi Town, Matsuda Town, and Kaisei Town have their own subsidy systems (we have not confirmed if Yamakita Town has its own system), and Oi Town has only a few remaining planned cases. The Kanagawa Prefecture subsidy (70,000 yen/kW for solar power and 150,000 yen per unit for storage batteries) is approaching the application deadline for the second period of fiscal year Reiwa 8, and the national DR household storage battery project has ended its public recruitment. Please check each official page for future applications.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies even after the construction is completed?
For many systems, procedures are required before construction. The subsidies from each town in Ashigarakami District and Kanagawa Prefecture often require “application before construction starts” or “start of construction after grant decision,” and if you install it first, you may be excluded from eligibility. The procedures differ by town.
The order of procedures varies by system, so please confirm before signing a contract or starting construction.
Can solar panels be installed on slate roofs? I’m worried about leaks.
It is possible to install on slate roofs, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and for methods that fix brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten Co., Ltd. is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation. If deterioration is progressing, we can also propose methods such as roof overlay (cover method) or complete replacement before installation.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed within 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the remaining lifespan of the roof is short, it may be more cost-effective to renovate with durable roofing materials before installation.
Please consult us on how to proceed with the installation after checking the condition of the roof during the on-site survey!
Is it better to install a storage battery together with solar panels?
For those who want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more advantageous to use it in your home rather than selling it.
Additionally, Kanagawa Prefecture’s subsidy requires the simultaneous introduction of solar panels and storage batteries. Please check the official pages of each town for the conditions of subsidies for each facility. You can compare “solar panels only” and “solar panels + storage battery” using a profit and loss simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram based on the drawings and on-site survey, and provide you with the installation capacity and power generation simulation.
In Ashigarakami District, the terrain varies from the Ashigara Plain to the mountains, and the way shadows are cast by neighboring houses, trees, mountain ridges, and elevation differences differs from house to house. You can check the expected power generation through the power generation simulation.
How long will the construction period be?
For the above construction example (solar panel 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is performed simultaneously or depending on the shape of the roof and installation capacity.
Additionally, please note that there will be a separate period for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (less than 10 kW), from the certifications after October 2025, the first 4 years will be 24 yen/kWh, and from the 5th to the 10th year, it will be 8.3 yen/kWh, and the same price will apply for the 2026 fiscal year.
The idea is to recover the initial costs more quickly in the first 4 years, and then focus on self-consumption. At Kakeru Koumuten, we provide a profit and loss simulation that takes into account loan interest rates and electricity prices.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-maintenance notices via DM and visits customers who wish to have inspections. We can also clean solar panels with a special brush if the power generation decreases due to dirt.
The roof is a part that is difficult to check by yourself, so please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, it is possible. Kakeru Koumuten Co., Ltd. can remove and reinstall solar panels in-house, allowing us to perform roof overlay (cover method) or re-roofing after temporarily removing the panels, and then reinstall them. The removed panels can be stored in our own warehouse.
For costs, please refer to the solar panel removal and hot water heater removal pricing page.
If you are looking for a solar panel installation company in Ashigarakami District, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Ashigarakami District, Kanagawa Prefecture.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “low-cost, high-quality renovations”, and we have received positive feedback from many customers.
We continue to update our number of completed projects each year, and we will strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior wall cover methods.
We are also happy to handle small jobs such as partial repairs and rain gutter cleaning!
In urgent cases such as leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and propose the best construction plans!
We are confident that we will not be outdone in terms of cost, quality, and organization compared to other companies in exterior construction!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if you find our company to be inferior to others, you are free to decline!
Characteristics of Ashigarakami District, Kanagawa Prefecture and Points of Solar Construction
The Ashigarakami District consists of five towns: Nakai Town, Oi Town, Matsuda Town, Yamakita Town, and Kaisei Town. According to official documents from Kanagawa Prefecture, the Ashigara Plain spreads out surrounded by the Nishitanzawa Mountain Range, the Hakone Outer Rim Mountains, and the Tsukahara Hills, with the Sakawa River flowing through the center. The area of each town varies, with Kaisei Town measuring 6.55 km², Oi Town 14.38 km², Nakai Town 19.99 km², Matsuda Town 37.75 km², and Yamakita Town 224.61 km², ranging from towns in the plain to those in the mountainous areas.
We have summarized the characteristics of Ashigarakami District and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Ashigarakami District and points for solar construction
■ From plains to mountains. Sunlight and shadows vary by town
According to the Kanagawa Prefecture Overview (official), the Ashigara region is described as having the Ashigara Plain spread out surrounded by the Nishitanzawa Mountain Range and the Hakone Outer Rim Mountains. In residential areas of the plain, shadows are mainly cast by neighboring houses, trees, and utility poles, while in mountain areas, shadows may change due to mountain ridges, slopes, and surrounding trees, affecting sunlight in the morning and evening. At Kakeru Koumuten, we create layout diagrams based on blueprints and site conditions, allowing you to confirm through power generation simulations.
■ In low-lying areas along the Sakawa River, also check the installation location of equipment
In the Ashigara Plain, where the Sakawa River flows through the center of the town, the expected flooding varies depending on your location. When deciding on the installation location for storage batteries and power conditioners, it is reassuring to check the flood expectations for your location on a hazard map. In mountainous and sloped areas, it is also important to confirm the relationship between the installation and the slope or retaining wall.
■ In mountain residences, consider fallen leaves and surrounding trees
In towns like Yamakita, which have extensive mountainous areas, or in hilly residential areas with many trees, fallen leaves and branches can easily accumulate on panels and rain gutters. If dirt such as fallen leaves and dust accumulates on the roof, it may affect power generation, so it is important to consider the arrangement of panels and the ease of cleaning and inspecting rain gutters.
■ Different subsidy application statuses and order by town
In Ashigarakami District, each town has its own unique system, with Nakai Town, Oi Town, Matsuda Town, and Kaisei Town each having different amounts, conditions, application orders, and acceptance statuses. We have not confirmed a unique system for Yamakita Town. It is important to check the system of your town in advance, along with the timing of the construction.
■ Check the roof condition according to the age of the building
For homes that have been built for many years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can help reduce future costs for removing and reattaching solar panels.
Our company is based in Kanagawa Prefecture and has extensive experience in exterior construction and solar work in Ashigarakami District.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any urgent issues!
Service Area in Ashigarakami District, Kanagawa Prefecture
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Ashigarakami District, Kanagawa Prefecture
Nakai Town, Ashigarakami District / Oi Town, Ashigarakami District / Matsuda Town, Ashigarakami District / Yamakita Town, Ashigarakami District / Kaisei Town, Ashigarakami District
・Trust Kakeru Koumuten for exterior wall painting in Ashigarakami District, Kanagawa!
・Trust Kakeru Koumuten for roof renovations in Ashigarakami District, Kanagawa!
・Trust Kakeru Koumuten for exterior renovations in Ashigarakami District, Kanagawa!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. service menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of getting multiple estimates and points to compare!
・Top 12 solar power manufacturers! Features and selection tips included!
・What are the installation costs for solar power? Tips for reducing costs thoroughly explained!
・What are the best locations for installing solar power? Points for selecting installation sites included!
・Check here for solar power estimates!
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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!
