[Kawasaki City, Saiwai Ward] Renovation of Used Properties and Vacant Houses | Costs, Subsidies, and Case Studies

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!

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

Aoki-ku, 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.

02Reasons 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

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

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

2. Interior (Interior Finishing)

3. Water-related Facilities

4. Equipment and Infrastructure

5. Waterproofing and Earthquake Resistance

6. Exterior Works

*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!

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

*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.

Kawasaki City Program

06Customer Feedback

Roof Overlay Construction Case Studies in Saiwai-ku

07How to Choose a Renovation Contractor for Used Properties and Vacant Houses in Aoba-ku

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

1. 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

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)

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

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

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

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.

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

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

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 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

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

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

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

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

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

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

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

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!

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.

空き家を放置すると、劣化や不法侵入、火災の危険など、さまざまなリスクが高まります。特に、雨漏りやシロアリの被害が進行すると、修繕費用が増大する可能性があります。また、周辺環境にも悪影響を及ぼすことがあるため、早めの対策が重要です。