Consultation for Renovation of Used Properties and Vacant Houses in Saiwai Ward

For those considering renovation of used properties and vacant houses in Saiwai Ward

I bought a used property, but I’m not sure if the renovation estimate I received is reasonable

This is my first full renovation, and I’m worried about making mistakes

I want to make the most of subsidies and grants

Kakeru Koumuten Co., Ltd., which has a wealth of experience and responds to such concerns in Aoki-ku, will clearly explain the key points for a successful renovation.

Obtain estimates from at least 3 companies!

Kakeru Koumuten Renovation of Used Properties and Vacant Houses

01Reasons for the Increase in Renovations of Used Properties and Vacant Houses in Aoki-ku

Saiwai Ward, Kawasaki City is located in the southeastern part of Kawasaki City, featuring a residential area along the Kashimada and Shinkawasaki redevelopment area and the Nambu Line. It is a convenient and livable town close to the Tama River and industrial zones.

In the densely populated flat urban area, there are many old wooden houses, and the generational transition of aging houses is progressing. This is why the option of “buying used single-family homes or condominiums and renovating (renovating) them to suit one’s lifestyle” is expanding in Aoki-ku.

A

Kashimada and Shinkawasaki Redevelopment Area

A popular area where convenience has improved due to redevelopment near the station. There is a growing demand for renovations of used condominiums and single-family homes.

B

Residential Area Along the Nambu Line

An area where houses are densely packed on flat land, with many wooden single-family homes. The movement to live on through used properties + renovations is active.

C

Wooden Density and Disaster Prevention

In densely populated urban areas, it is important to review seismic and fire safety measures. In narrow locations, ingenuity in scaffolding and transportation is also required.

D

Considerations for Locations Along the Tamagawa River

For locations near the Tamagawa River, it is advisable to check the hazard map and consider flood prevention measures as necessary.

This article summarizes the reasons, precautions, cost estimates, the latest subsidies for 2026, and tips for choosing contractors from the perspective of Kakeru Koumuten Co., Ltd. for those considering renovating used properties and vacant houses in Saiwai Ward to ensure they do not “make mistakes.”

The Most Important Thing is “Comparative Estimates”

The most crucial factor in avoiding mistakes during renovations is comparative estimates. First, obtain estimates from at least three companies that operate in Saiwai Ward. Our company, Kakeru Koumuten Co., Ltd., also receives many inquiries and requests for consultations and renovations of vacant houses and used properties.

02Reasons for Renovating Vacant Houses and Used Properties

Reasons for Renovating Vacant Houses and Used Properties

In recent years, the Japanese housing market has expanded options not only for new builds but also for renovating used properties. There is growing interest in living in renovated or refurbished used homes. Here, we explain the typical reasons for renovating vacant houses and used properties.

Reason 1 To Live Comfortably as Your Own Home

One of the main reasons for purchasing and renovating a used property is “to live comfortably.” Older homes often have issues with the roof, exterior walls, and plumbing, making them less livable as they are. By renovating and upgrading the facilities and interiors, you can create a comfortable living environment. Moreover, with changes to the layout and refreshing the interior, depending on the renovation work, you can achieve a home that suits your family’s lifestyle while keeping costs lower than new construction.

Reason 2 To Increase Asset Value for Sale

More people are purchasing and renovating used properties with the intention of selling them. Used homes are often valued low as they are, but renovations can enhance their appearance and performance, thereby increasing their value as properties.

Reason 3 To Utilize as an Investment or Business

For purchases made for investment or business purposes, renovations are essential. By transforming them into stylish rentals or share houses, you can differentiate them from other properties, and depending on the location and planning, you can also expect improved profitability. Initial costs can be lower than new construction, and depending on the use and conditions, they may also qualify for subsidies and tax incentives, leading to an increase in the number of people utilizing vacant houses for business.

03Precautions When Renovating Vacant Houses and Used Properties

Points to Consider for Renovation

Point 1 Choose a Reliable Construction Company

First and foremost, it is essential to select a contractor you can trust to handle your renovation with peace of mind. Since used properties have had previous occupants, the internal structure and condition are often not clear until you see them in person. Choose a contractor who can carry out the work thoroughly according to your wishes, the structure of your home, and the surrounding environment, and who also provides aftercare following the construction.

Point 2 Always Check the Deterioration of the Building

For used properties and vacant houses, it is crucial to confirm which parts have deteriorated and to what extent beforehand. Since other people have lived there before, many internal damages are often not apparent without investigation. Conduct a current condition survey before starting work to identify any hidden deterioration.

Point 3 Review Earthquake Resistance and Insulation Performance

Particularly important in the renovation of used and vacant houses is the review of earthquake resistance and insulation. The earthquake resistance standards were significantly revised in 1981, and homes built before that may not meet current standards. Furthermore, in 2000, regulations regarding joints and foundations were strengthened, making older buildings more likely to lack earthquake resistance. Check the condition of the building before starting work and be sure to check earthquake resistance and insulation performance.

Point 4 Check Subsidy Programs and Renovation Tax Deductions

To keep construction costs down, it is important to check for subsidies and renovation tax deductions. Subsidies are provided by the national and local governments, supporting part of the costs for earthquake retrofitting, energy-saving construction, and barrier-free renovations. Tax deductions include the “housing loan tax deduction” when using a housing loan, and there are systems where a portion of the costs can be deducted for certain works even with personal funds. Since these can sometimes be used together, it is crucial to check in advance and plan to utilize them strategically as a key to successful renovation (for the latest information, see this subsidy section).

04 Cost Estimates for Renovating Vacant Houses and Used Properties

Cost Estimates for Renovation

The renovation costs for used properties and vacant houses vary significantly depending on the extent of damage and the scope of work. First, please understand the approximate market prices by area to serve as a guideline for your financial planning (the table below provides general estimates for single-family homes. The interior is based on a room of about 6 tatami mats, and the exterior is based on the indicated scope of work. Actual estimates will be provided after a site survey).

1. Roof and Exterior Walls

Construction Content Estimated Cost
Roof Repair and Painting Approximately 200,000 to 800,000 yen
Roof Replacement / Roof Overlay (Cover Method) Approximately 700,000 to 2,500,000 yen
Exterior Wall Painting Approximately 600,000 to 1,500,000 yen
Exterior Wall Replacement / Cover Method Approximately 1,500,000 to 3,000,000 yen

2. Interior (Interior Finishing)

Construction Content Estimated Cost
Floor Replacement (approximately 6 tatami mats, flooring, etc.) Approximately 100,000 to 300,000 yen
Wallpaper Replacement (approximately 6 tatami mats) Approximately 50,000 to 150,000 yen
Ceiling Repair and Painting (approximately 6 tatami mats) Approximately 30,000 to 100,000 yen
Renovation from Japanese-style Room to Western-style Room (1 room) Approximately 200,000 to 600,000 yen

3. Water-related Facilities

Construction Content Estimated Cost
Kitchen Replacement Approximately 450,000 to 1,500,000 yen
Bathroom Renovation (Unit Bath) Approximately 600,000 to 1,500,000 yen
Toilet Replacement Approximately 120,000 to 500,000 yen
Vanity Replacement Approximately 80,000 to 300,000 yen

4. Equipment and Infrastructure

Construction Content Estimated Cost
Water Heater Replacement Approximately 100,000 to 500,000 yen
Pipe Replacement (Aging Water Pipes, etc., Partial Work) Approximately 100,000 to 500,000 yen
Electrical Wiring Work (Partial Work) Approximately 100,000 to 500,000 yen
Insulation Renovation (Replacing Multiple Windows, Installing Inner Windows, etc.) Approximately 200,000 to 1,000,000 yen

5. Waterproofing and Earthquake Resistance

Construction Content Estimated Cost
Balcony Waterproofing Work Approximately 100,000 to 400,000 yen
Seismic Reinforcement Work Approximately 500,000 to 2,000,000 yen

6. Exterior Works

Construction Content Estimated Cost
Entrance Door Replacement Approximately 200,000 to 500,000 yen
Gate and Fence Renovation Approximately 200,000 to 800,000 yen
Parking Lot Maintenance (for 1 car, including concrete pouring, etc.) Approximately 200,000 to 600,000 yen

*The above are general estimates. Costs may vary depending on the presence of scaffolding, the condition, grade, and area of the building. Waterproofing of rooftops and updates to plumbing and wiring throughout the house may exceed the above estimates depending on area and method. Please confirm the exact costs through a free on-site survey and estimate.

For more details, please see our construction menu and price list!
Kakeru Koumuten's Construction Menu

05[Latest 2026] Subsidies and Grants Available in Saiwai Ward

Utilize subsidies and grants for cost-effective renovations

One way to renovate used properties and vacant houses cost-effectively is by utilizing the subsidy and grant system. As of 2026, we have summarized the main systems that residents of Saiwai Ward may be able to use.

*The following information is as of September 3, 2026. The details, duration, and budget of the systems change each fiscal year, and many will end once the budget limit is reached. Please check for the latest information with our company or the respective offices before applying. Kakeru Koumuten can assist with confirming the systems and providing necessary documents, but the applicant and application methods differ depending on the system.

National Program: Housing Energy Saving 2026 Campaign

The government is implementing multiple subsidy projects targeting energy-saving renovations under the “Housing Energy Saving 2026 Campaign.” Construction for insulation, windows, and water heaters may be eligible for these subsidies.

Mirai Eco Housing 2026 Project Insulation & Energy Saving Renovation
Up to 1,000,000 yen per unit

This program succeeds the “Child-Rearing Green Housing Support Project.” It targets insulation and energy-saving renovations that meet certain criteria, including insulation renovations for openings and structures, eco-friendly housing equipment, child-rearing support renovations, disaster prevention improvements, and barrier-free renovations.

The maximum subsidy is 1,000,000 yen per unit for buildings constructed before 1991, and 800,000 yen per unit for those built between 1992 and 2016. For projects that meet the obligation standards for the maximum amount, the requirements include “insulation renovation for openings + insulation renovation for structures + installation of specific eco-friendly housing equipment.” For projects that meet next-generation energy-saving standards, the limits are 500,000 yen and 400,000 yen, respectively. Construction must start on or after November 28, 2025, with reservations by November 16, 2026, and subsidy applications by December 31, 2026 (subject to early termination if the budget limit is reached). Applications are made by registered contractors. For more details, please check the official page.

Advanced Window Renovation 2026 Project Windows & Insulation
Up to 1,000,000 yen per unit

This program covers window insulation renovations such as installing interior windows, replacing exterior windows, and glass replacements. The subsidy amount is significant and effective for addressing cold, heat, and condensation issues. It can easily enhance the insulation performance of existing homes.

The subsidy amount varies based on the window method, performance, size, and construction style of the house. If the total subsidy amount for one application is less than 50,000 yen, it is not eligible. Applications have been accepted since March 31, 2026, with subsidy applications due by December 31, 2026 (subject to early termination if the budget limit is reached). Applications must be made by registered contractors. For more details, please check the official page.

Water Heating Energy Saving 2026 Project High-Efficiency Water Heaters
Up to 170,000 yen per unit

This program targets the replacement of high-efficiency water heaters such as eco-cute, hybrid water heaters, and EneFarm. It is well-suited for used properties planning to replace water heaters.

The basic subsidy amounts are 70,000 yen per eco-cute unit, 100,000 yen per hybrid water heater unit, and 170,000 yen per EneFarm unit. There may be performance bonuses depending on the eligible equipment. Only projects started on or after November 28, 2025, are eligible (subject to early termination if the budget limit is reached). For more details, please check the official page.

Kawasaki City Program

Kawasaki City Wooden House Earthquake Resistance Renovation Subsidy System Earthquake Resistance
General households up to 1.3 million yen / Non-taxable households up to 1.8 million yen

This is the main system for reinforcing old wooden houses against earthquakes. It is effective for earthquake resistance renovations combined with the purchase of used detached houses. Dispatch of earthquake diagnosis specialists is free.

Whole building renovation: General households up to 1.3 million yen / Non-taxable households up to 1.8 million yen (subsidy rate 4/5). Partial renovation: General 1 million yen / Non-taxable 1.35 million yen. Eligible properties are wooden houses with two stories or less and traditional frame construction that started construction before May 31, 2000. As of April 2026 (Reiwa 8), the scope has been expanded to include wooden houses built under the new earthquake resistance standards (up to May 2000). The application period and budget status may change, so please check (Contact: Urban Development Bureau). For details, visit the official Kawasaki City page.

Kawasaki City Elderly Housing Renovation Cost Subsidy Project Barrier-Free
Standard limit amount 1 million yen

This program is for individuals aged 65 and older who have received certification of needing support or higher. Renovations for bathrooms, entrances, hallways, and stairs that are “other than” home modifications under long-term care insurance are eligible, and it is also useful when utilizing used houses for multi-generational living.

Standard limit amount is 1 million yen. The user burden rate is set in 7 stages according to income. Pre-consultation before starting construction is required (applications after construction has started are not eligible). For details, visit the official Kawasaki City page.

Home Renovation under Long-Term Care Insurance Barrier-Free
Payment limit standard amount 200,000 yen (maximum benefit 180,000 yen)

This program is for individuals who have received certification of needing support or long-term care. Eligible expenses include installation of handrails, elimination of steps, changes to flooring materials, and replacement of doors and toilets.

Out of the payment limit standard amount of 200,000 yen, those with a 10% burden will receive 90% (maximum 180,000 yen) as a benefit. There may be cases of 20% or 30% burden depending on income. Pre-application before starting construction is required.

Kawasaki City Solar Power Generation Equipment Installation Subsidy Solar Power & Storage Batteries
Solar power 70,000 yen/kW (maximum 280,000 yen) / Storage batteries 100,000 yen/kWh (maximum 700,000 yen or 300,000 yen)

This is a city program for those looking to install solar power and storage batteries in conjunction with the renovation of used properties. There are also fixed subsidies for ZEH and ZEH+.

Main guideline: For solar power systems not subject to FIT, the cost is 70,000 yen/kW with a maximum of 280,000 yen. For storage batteries, the cost is 100,000 yen/kWh, and when connecting newly installed solar power systems not subject to FIT, the maximum is 700,000 yen; when connecting to solar power systems subject to FIT or existing solar power systems, the maximum is 300,000 yen. For ZEH/ZEH Oriented, the amount is 250,000 yen per unit, and for ZEH+, it is 400,000 yen per unit. The application period for the 2026 fiscal year is from April 24, 2026, to December 28, 2026, and it may end early depending on budget conditions. For more details, please visit the official page of Kawasaki City.

* In Kawasaki City, there does not appear to be a city-specific subsidy system that targets only general exterior wall painting or roof repairs, based on the information confirmed this time. There are city systems for seismic resistance, barrier-free access, and solar power, depending on conditions, and it is recommended to check the national “Housing Energy Efficiency 2026 Campaign” for insulation and window work.

View information about renovation tax reductions and other systems
  • Housing Loan Tax Reduction: If you use a housing loan for renovations that meet certain requirements, income tax and other deductions will be applied based on the year-end balance.
  • Renovation Promotion Tax System (Investment-type Tax Reduction): For construction related to seismic resistance, energy conservation, barrier-free access, and long-term excellent housing, there may be cases where income tax deductions can be received even with personal funds.
  • Reduction of Fixed Asset Tax: There is a system that reduces fixed asset tax for a certain period for seismic retrofitting, energy conservation retrofitting, and barrier-free retrofitting.
  • Kanagawa Prefecture Existing Housing Energy Conservation Renovation Subsidy: For the 2026 fiscal year, the subsidy rate is 1/3 with a maximum of 150,000 yen. The first phase has ended, but additional applications are planned from September 7, 2026, to September 30, 2026, via electronic application only, on a first-come, first-served basis (approximately 25 cases). Applicants must apply themselves, and construction before the grant decision is not eligible. Please check the official page of Kanagawa Prefecture.

While subsidies and tax reductions can sometimes be combined, there are restrictions on duplication for the same work. Kakeru Koumuten will organize and propose which systems can be used for your work after conducting a site survey.

06Customer Feedback

Roof Overlay Construction Case Studies in Saiwai-ku

BEFORE

Kawasaki City Saiwai Ward Slate Roof Roof Overlay Construction Before

AFTER

Kawasaki City Saiwai Ward Dannetsutop Roof Overlay Construction After

Construction Location Kawasaki City, Saiwai Ward
Construction Details Temporary scaffolding installation / roof overlay (cover method)
Existing Roofing Material Slate
New Materials Used Roofing Material: Sekino Kousan / Dannetsutop (Color: Silver / Estimated Durability: About 30-35 years / Manufacturer’s Product Warranty: Coating 15 years, Puncture 25 years / In-house Construction Warranty: 10 years)
Roofing: Tajima Roofing / New Liner Roofing (Estimated Durability: Over 30 years)
Ridge Base: Galvalume Steel (Estimated Durability: Over 30 years)
Metal Fasteners: Stainless Steel Screws with Packing / Sealing: Auton Exceed
Price Range 500,000 – 600,000 yen
Completion Month August 2024

Our Proposal

The existing slate roof showed overall deterioration, and simply painting it could lead to the risk of roofing material falling in the future. Therefore, we proposed the roof overlay (cover method) to install new roofing material without removing the existing roof.

For the new roofing material, we selected Sekino Kousan’s Dannetsutop, which offers an excellent balance of cost performance and durability. This lightweight metal roofing material comes with insulation on the back, enhancing the roof’s durability while also improving insulation. For waterproofing, we used New Liner Roofing, and for the ridge base, we used Galvalume steel, ensuring a construction specification that considers the overall durability of the roof.

07How to Choose a Renovation Contractor for Used Properties and Vacant Houses in Saiwai Ward

There are many renovation companies that serve Saiwai Ward, and it can be confusing to decide which one to choose. When requesting renovations, be sure to check the following five points.

  • Experience in renovation work
  • Check for warranties and after-sales maintenance
  • Obtain estimates from multiple contractors (at least three)
  • Confirm whether they perform renovations in-house
  • Check if they offer color simulations and perspective drawings

1. Experience in Renovation Work

Experience in Renovation Work

Many renovation contractors publish their work results on their websites. If a contractor provides detailed explanations of the process with photos, it can give you a clearer image of what to expect after hiring them, which is reassuring. If you’re uncertain, choose a contractor with ample experience.

Google and review sites can also be helpful. It’s important to check the content of low ratings, the company’s responses, and the timing of the posts. Google reviews are particularly useful, but don’t make your decision based solely on reviews; consider the contractor’s work results, estimates, and warranty details for a comprehensive judgment.

2. Check for Warranties and After-Sales Maintenance

Warranties and After-Sales Maintenance

When choosing a contractor, be sure to check for warranties. If repairs are needed within the warranty period, they may be done for free. The duration varies depending on the contractor, the nature of the work, and the materials used, but it can range from 1 to 10 years (emergency repairs or partial repairs are often not covered). Some contractors also offer after-sales services separate from warranties, so be sure to check that as well.

Kakeru Koumuten Co., Ltd. provides a warranty for all exterior renovations and sealing work. We also conduct aftercare maintenance and send out annual notification DM, making annual inspections possible.
Click here for more details on Kakeru Koumuten’s warranty and aftercare maintenance

3. Obtain estimates from multiple contractors (at least 3 companies)

Obtain estimates from multiple contractors

When requesting renovations, be sure to obtain estimates from multiple contractors. Even for the same construction details, warranties, after-sales services, and prices can vary significantly. Having multiple estimates makes price negotiations easier.

When comparing estimates, it’s important to look at not just the costs, but also the “items in the estimate,” “check the primer, sealing materials, and paint for ancillary parts,” and “confirm the process.” Lowering the rank of ancillary parts or skipping steps can reduce costs, so it’s crucial to not make decisions based solely on price.
See detailed points for comparing estimates

4. Confirm whether the company conducts renovations in-house

Confirm whether the company conducts renovations in-house

At Kakeru Koumuten, we carefully listen to and investigate the existing “condition,” “location,” “base materials,” “desired durability,” and “design” to propose the best plan. While there is nothing inherently wrong with a system where partner companies perform the work, it’s important to confirm whether the contracting company understands the construction details and has clear responsibilities for quality control and warranties. If the work is done in-house, it is easier to coordinate with the site, allowing for quicker responses in case of any issues.

5. Check if they offer color simulations and perspective drawings

Color simulation and perspective drawing

Choosing colors and envisioning the post-construction look can be challenging for both exterior and interior projects. With simulations, you can reduce the risk of mistakes like “it turned out differently than I imagined.” Since it is difficult to redo once the work is done, it is advisable to choose a company that can provide flexible simulations.

08Reasons why Kakeru Koumuten is chosen for renovations of used houses in Saiwai-ku

Reasons to Choose Kakeru Koumuten

One reason is that Kakeru Koumuten Co., Ltd. serves Saiwai Ward, but
our unique approach to “renovating vacant houses and used properties” that cannot be imitated by other companies
has received high praise from many customers.

We have absolute confidence in “cost,” “quality,” and “plans” for renovations in Saiwai Ward. Please compare our estimates with those of other companies.

The most important aspect of renovations is getting multiple estimates. Be sure to request estimates from at least 3 companies that serve the Saiwai Ward area!

1. Equipment Specialized for In-House Renovations

At Kakeru Koumuten, we have organized warehouses and material storage areas to provide high-quality renovations at low costs. We have 5 bases located within Yokohama City for material storage and showrooms.

In-House Scaffolding Materials

In-House Scaffolding MaterialsIn-House Scaffolding Team
We can construct the temporary scaffolding necessary for exterior renovations using our own scaffolding materials and in-house scaffolding team. By not outsourcing, we achieve cost reductions on scaffolding work. We own scaffolding materials for approximately 50 detached houses.

Storage of Materials in Our Large Warehouse

In-house large warehouseMaterial storage
We store roofing materials and paints. By placing large orders at once, we can procure materials at a lower cost, and since we always have stock available, we can respond quickly in emergencies. We also have various tools ready for different types of construction, including compressors and cleaning machines.

In-house waste separation

In-house waste separation
In exterior renovations, various types of waste such as paint, wood, and metal are generated. While many contractors dispose of them all together, our company separates and recycles waste, significantly reducing waste disposal costs.

Exterior renovation dedicated showroom

Exterior renovation dedicated showroomShowroom interior
In the showroom, you can not only have meetings but also check the actual paint colors and a wide range of catalogs. Color simulations and tests for heat-reflective paint can also be conducted. The showroom is a 3-minute walk from Eda Station in Aoba-ku, Yokohama, and is easily accessible from Kawasaki City.

2. Complete in-house construction

Complete in-house construction

A major strength of Kakeru Koumuten Co., Ltd. is our complete in-house construction. By maintaining a consistent system from inquiry to project completion, we can keep costs down while delivering high-quality renovations. A single representative handles everything from the estimate to project completion, ensuring smooth communication without changes in sales or construction management. All work, from temporary scaffolding installation to exterior painting and roof renovations, is carried out by our own skilled craftsmen. We are confident in our plans and costs, so we welcome competitive estimates.

3. Various Permits and Skilled Workers

Construction Industry LicenseSkilled Workers
We have obtained permits for the construction industry and for the collection and transportation of industrial waste. We also have nationally certified sheet metal workers and painting specialists on staff, ensuring confidence in our construction techniques. We are capable of handling large-scale painting projects for factories and apartment complexes.

4. Warranty and Aftercare

Warranty and Aftercare

Exterior painting and joint sealing work come with a warranty. Aftercare is available annually, and we send out notification DM each year. If you have concerns about the warranty, please click the image above for more information.

5. Flexible and Prompt Response

Flexible and Prompt Response

We are equipped to handle various exterior troubles and situations. If you cannot access the roof at height, we can respond using a drone. For leak investigations, we also utilize a thermal imaging camera. We respond according to our customers’ wishes and also accept emergency measures for sudden leaks from exterior walls.

6. Human Resource Development

Human Resource Development

We create various models to enhance skills and conduct practical training. Since the construction methods and materials used for exterior renovations differ based on existing materials and shapes, we conduct regular technical training to ensure that each staff member can respond to various sites.
Click here for company information

7. Flexible simulations for both exterior and interior renovations!

Kakeru Koumuten Co., Ltd. is dedicated to helping our customers choose colors and designs for their important building renovations, ensuring their satisfaction with both exterior and interior work.

7-1. Exterior Renovation Simulation

Exterior Renovation Simulation

We can create color simulations for exterior wall painting, as well as simulations for metal siding and roof overlays. We can generate simulations from actual photos of your building and propose several color patterns based on our recommendations. We also accommodate “test painting” and “sample board arrangements” to confirm actual color tones.

7-2. Interior Renovation Simulation

Interior Renovation Simulation

We also support simulations and perspective drawings for interior renovations. Based on your preferred style, such as modern, we can suggest recommended simulations. We create realistic perspectives from actual floor plans.

8. We also handle solar panel and battery installation work!

Solar Panel and Battery Installation Work

More customers are introducing solar equipment, which has generous subsidies, in conjunction with renovations of used properties. Kakeru Koumuten Co., Ltd. also handles solar equipment installation and can propose solar panels tailored to the shape of your roof. We can also accept requests for estimates and power generation simulations only.

09Existing and Vacant Home Renovation in Saiwai Ward | Frequently Asked Questions

Here are answers to common questions from people considering renovation of existing or vacant homes in Saiwai Ward.

Should I arrange renovations after buying an existing home, or consult you before buying?

If possible, please consult us before deciding to buy. Existing homes may have deterioration that is not visible, and unexpected construction costs after purchase are not uncommon. By checking the condition of the property you are considering and estimating the necessary renovations in advance, Kakeru Koumuten can help you make a realistic financial plan.

Which renovations should take priority in an existing detached house in Saiwai Ward?

Priorities depend on the building’s condition. We first address problems that can worsen if left untreated, including leaks, termites, structural issues and earthquake resistance. We then determine the order of work on the roof, exterior walls and other exterior elements, the kitchen, bathroom and toilet, and thermal insulation, according to your budget and the impact on daily life. In flat residential areas along the Nambu Line and around Kashimada and Shin-Kawasaki, roofs and exterior walls may reach the end of their service life first, so we recommend inspecting the entire building, including the exterior.

I bought an existing detached house in Saiwai Ward. What should I check first?

Saiwai Ward has many wooden detached houses in densely built-up flat urban areas. We recommend starting with checks of earthquake resistance, fire protection and the exterior. Confined sites require careful planning of scaffolding and deliveries. For properties near the Tama River, also check the hazard map. Kawasaki City’s wooden-house seismic retrofit subsidy may be available (general maximum: 1,300,000 yen; subsidy rate: 4/5; eligibility expanded from 2026 to include homes built to the newer seismic standards), and we propose ways to reduce costs accordingly.

How much does a full renovation cost?

The cost of fully renovating a detached house varies greatly with the scope and specification. Work focused on partial renovations starts at around 5 million yen, while extensive renovations covering the interior, exterior, kitchen and bathrooms, insulation and seismic upgrades may cost 10–20 million yen or more. We first inspect the property and propose a plan with priorities that fit your budget.

Do I apply for subsidies myself? Is the procedure difficult?

The applicant varies by program. For example, under the national Mirai Eco Housing 2026 program, registered contractors (construction companies) submit the application. Municipal seismic retrofit subsidies and home modifications covered by long-term care insurance generally require the individual to apply, but we explain the necessary documents and steps. We can also help you identify which programs may be available, so please contact us.

What risks arise if a vacant house is left unattended?

Water leaks and termite damage may worsen, deteriorating roofs and exterior walls can reduce property value, and garden trees and equipment may fall into neglect. If the municipality issues a recommendation concerning a poorly managed vacant house or a designated vacant house, the residential land exemption for fixed asset tax may cease to apply. Inspecting the property early and carrying out the necessary work according to your plans to live in, rent, sell or otherwise use it can help reduce costs in the long run.

I am concerned about earthquake resistance. How should I assess an existing detached house?

The construction date is an important guide. Check whether the house was built in or after June 1981 (the newer seismic standards), and in or after June 2000 (stricter rules for connections and foundations). We recommend a seismic assessment for wooden detached houses built earlier. Your municipality also offers subsidies for seismic retrofitting of wooden houses, which can substantially reduce costs if you qualify (see the subsidy section above). Kakeru Koumuten can advise you from assessment through renovation.

Will I need temporary accommodation during construction? How long will the work take?

It depends on the scope of work. Exterior renovations and partial interior work can often be carried out while you continue living in the home, but we may recommend temporary accommodation for extensive full renovations involving the kitchen and bathrooms. Typical durations are about 2–4 weeks for exterior work and about 1–3 months or more for full renovations. We provide a schedule in advance and propose a plan that minimizes disruption to daily life.

Is Saiwai Ward within your service area? Are there travel charges?

Yes, Saiwai Ward is within Kakeru Koumuten’s service area. Our headquarters is in Aoba Ward, Yokohama, and we have 5 bases within the city, serving all of Kanagawa and Tokyo. Estimates are completely free, and we do not use persistent sales tactics. Please feel free to contact us.

Leave your renovations in Saiwai-ku to Kakeru Koumuten!

“I want my renovation to last a long time with just one go,” “I want to keep costs down as much as possible,” “I want to improve insulation because my home is hot” — we will propose the best solutions for your specific requests. We do not suggest unnecessary work that prioritizes profit.

We are confident in our costs, quality, and planning, so we welcome comparison estimates. Our estimates are completely free.

Get your free estimate and consultation here

If you find our company to be inferior to others, feel free to decline outright.

See Kakeru Koumuten’s case studies
View our construction menu and price list

10Features of Saiwai-ku

Saiwai Ward, Kawasaki is located in the southeastern part of Kawasaki City, featuring the redevelopment areas of Kashimada and Shinkawasaki, as well as residential areas along the Nambu Line. Close to the Tamagawa River and industrial zones, it is a convenient and livable town.

The old wooden houses in the densely populated flat urban area are reaching a generational transition, and the choice of continuing to live in them through renovation and resale is becoming established. Kakeru Koumuten Co., Ltd. is headquartered in Aoba-ku, Yokohama, and offers a wide range of exterior and interior renovations throughout Kawasaki City. We can perform all work in-house, including exterior wall overlay methods.

Renovation Service Areas

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

Service Areas in Saiwai Ward, Kawasaki (Main Areas)

Endo-cho / Omiya-cho / Ogura / Kashimada / Kawahara-cho / Kitakase / Komukai / Komukai-cho / Komukai Toshiba-cho / Komukai Nakano-cho / Komukai Nishi-cho / Konyamachi / Saiwai-cho / Shimohirama / Shinkogura / Shinkawasaki / Shintsukagoshi / Shinmei-cho / Tsukagoshi / Tode / Tode Honmachi / Nakasaiwai-cho / Higashi Ogura / Higashifuruichiba / Furuichiba / Furukawa-cho / Horikawa-cho / Minamikase / Minamisaiwai-cho / Miyako-cho / Yagami / Yanagimachi and other areas throughout Saiwai-ku

We welcome consultations via LINE as well◎

LINE

Consult via LINE

We are also updating our Instagram regularly◎ Please follow us!

Instagram

Kakeru Koumuten Instagram

For roof, gutter and exterior construction and repairs in Kanagawa,
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!