【2026年最新版】東京都の窓リフォーム補助金は継続！“実質0円”も可能｜賃貸オーナー様は今すぐ動くべき理由

For Those Considering Window Renovation in Tokyo

Thanks to your continued support,

Mad Honpo Shinjuku (Aikawa Three F Co., Ltd.) has received an overwhelming number of window renovation orders from customers across Tokyo.

And now, for fiscal year 2026—

Let us begin with the conclusion.

■ Subsidies in 2026 Are Not Only Continuing — They Are Strengthened

From April 1, 2026 onward, the following programs will remain in effect:

• National subsidy program (Advanced Window Renovation Project)
• Tokyo Metropolitan Government subsidy programs (Cool Net Tokyo, etc.)

👉 These programs have been officially confirmed to continue

Even more surprising:

• Additional subsidies for large openings and large windows
• Increased evaluation and support for high-performance windows

This creates a strong tailwind that goes against previous industry expectations.

Originally, it was widely assumed that:

“Subsidies would be reduced after 2026”

However, in reality:

👉 What we are seeing is an extension of what may be the “last major opportunity.”

■ Conclusion: 2026 Rewards Those Who Act Immediately

In simple terms:

👉 First come, first served

The reasons are clear:

• Budgets are limited
• Timing of application is critical
• Construction capacity is finite

■ For Property Owners: Studios, 1K, and 1LDK Units Can Be Virtually Free

In Tokyo’s rental market, especially for:

• Studio (1R)
• 1K
• 1LDK units

👉 Interior window installation is often almost fully covered by subsidies

✔ Owner Cost

👉 Effectively 0 yen (consumption tax only)

At Mad Honpo Shinjuku, we continue to successfully deliver this model.

⚫️ Important Point

👉 We are a certified “Tokyo Energy Efficiency Diagnostic Provider.”

From:

• Diagnosis
• On-site measurement
• Cost estimation
• Design
• Construction
• After-sales support

👉 Everything is handled in-house, end-to-end

■ Why Is “Zero Cost” Possible?

There are three key factors:

1. Triple Subsidy Structure (National + Tokyo + Ward)

• National: Major subsidies for high-performance insulation windows
• Tokyo: Additional subsidies (Cool Net Tokyo)
• Local wards: Additional top-ups depending on area

👉 Total subsidies can nearly match the full construction cost

2. One-Stop System

We provide:

• Design
• Cost estimation
• Construction
• Subsidy application

👉 All handled internally

This allows us to:

👉 Eliminate unnecessary costs to the maximum extent

3. Economies of Scale

With extensive project experience across Tokyo:

👉 We optimize both materials and construction processes

■ Why Property Owners Are Taking Action Now

Recent inquiries often include:

• “We want better insulation and soundproofing to reduce vacancies”
• “We want to increase rent with added value”
• “We want to maintain the value of aging properties”

But the most common reason is:

👉 “If we’re going to do it, now is the time—while subsidies exist.”

■ Reality of 2025: “Too Late After Summer”

Looking back at 2025:

Actual Conditions:

• After summer → demand surged
• Autumn → waiting lists formed
• Winter → last-minute subsidy applications

Result:

👉 Many customers said, “We wanted to do it, but couldn’t make it in time.”

■ Why 2026 Will Be Even More Competitive

Compared to last year:

• Greater awareness of subsidy continuation
• Increased activity among property owners
• Limited capacity among contractors

👉 Competition will intensify significantly

■ Our Strength: Mad Honpo Shinjuku

We are not just a window contractor.

Mad Honpo Shinjuku / Aikawa Three F Co., Ltd.

• First-Class Architectural Office
• Authorized LIXIL Distributor
• General Construction Company

In addition:

• Estimation Department
• Design Department
• Construction Department

👉 Full company-wide collaboration

👉 This enables us to handle everything from single-family homes to large-scale apartment buildings.

■ Service Area

Primarily across Tokyo’s 23 wards:

• Shinjuku
• Shibuya
• Meguro
• Setagaya
• Toshima
• Itabashi
• Edogawa
• Katsushika
• Adachi

…and all other areas within Tokyo.

■ Frequently Asked Questions (FAQ)

Q. Is it really possible to achieve zero cost?

→ Depending on conditions, there is a very high probability (tax only applies).

Q. Is condominium association approval required?

→ Yes, but we provide full support.

Q. How long does construction take?

→ Approximately half a day to one day per unit

Q. Can work be done while tenants are present?

→ Yes, scheduling is handled flexibly.

■ Why You Should Act Now (Summary)

• Subsidies are continuing and expanding
• Budgets are limited
• Demand will surge after summer
• Construction capacity is limited

👉 Conclusion: 2026 is first come, first served

■ Contact & Consultation

We are already receiving a high volume of orders.

👉 Acting early this year gives you a decisive advantage

We offer:

• On-site inspections
• Preliminary estimates
• Subsidy simulations

👉 All free of charge

■ Final Message

Window renovation in Tokyo has entered a new phase.

👉 It is no longer about “whether to do it”

👉 It is about “when to do it”

And the answer is clear:

👉 Now.

Additional Notes

• There is still a strong possibility that subsidies will shrink or end after 2026
• Preferential treatment for large windows may be limited to this year
• The rental property market is already moving—information gaps are becoming profit gaps

There is only one conclusion:

👉 The opportunity is now

We are ready to take on your project smoothly and without delay—but only if you act now.

Please feel free to contact us anytime.