Japan’s Building Standard Law Has Changed — What It Means for Akiya Buyers in 2025

As of April 2025, an important update to Japan’s Building Standard Law has officially come into effect and it has meaningful implications for anyone buying or renovating vacant homes, known as akiya. Whether you're a DIY renovator, real estate investor, or simply planning to turn a countryside retreat into a guesthouse, here's what you need to know.

What Changed in the Law?

Until now, wooden one- and two-story homes under 200 square meters were largely exempt from needing building permits for renovations. This legal gray zone allowed many homeowners particularly those restoring older or abandoned homes to undertake substantial renovations without submitting plans or navigating costly bureaucratic processes.

But as of this month, all two-story wooden buildings will now require a building permit, regardless of their size. This change broadens the scope of properties subject to formal regulation, capturing the vast majority of Japan’s aging residential stock which includes most akiya.

The Impact: Higher Costs, More Paperwork

This updated regulation is expected to increase renovation costs across the board. In addition to the permit application itself, homeowners must now prepare and submit detailed structural reports and energy efficiency documentation. The review process also introduces delays, as applications go through municipal inspection and approval. For buyers on a budget or those hoping to streamline DIY renovations, this could significantly complicate project timelines and finances.

What About DIY Renovations?

If you're a current or prospective akiya owner wondering whether this affects your plans, the answer is a bit more nuanced.

After consulting with our team on the ground in Japan, it's clear that interior renovations such as kitchens, bathrooms, and cosmetic upgrades may still fall into a gray area. Local authorities are unlikely to actively police every small-scale, interior remodel. Japan’s government tends to take a pragmatic approach, and enforcing every minor renovation would risk disrupting large retail chains like DCM and Viva Home, which rely on the DIY renovation market.

In short: if your renovations are internal and non-structural, you're likely still operating within acceptable bounds especially if you're not altering load-bearing walls or expanding square footage.

When You Should File for a Permit

However, if your plans include any of the following, it's strongly recommended to go through the permitting process:

• Adding a second floor or expanding the structure’s footprint
• Major exterior changes, such as new walls, roofing, or structural reinforcements
• Renovations intended for commercial use, such as applying for a Minpaku (short-term rental) or Ryokan license

In these cases, going through the formal permit process will help you avoid legal complications, insurance issues, and potential penalties particularly if you're hoping to operate legally as a licensed lodging provider.

Final Thoughts

While the new law introduces more red tape for akiya renovators, it’s not a dealbreaker especially for those doing light DIY work. The key is knowing where the lines are drawn and planning accordingly. For investors and aspiring hosts, getting ahead of these changes and working with professionals who understand local permitting procedures will be more important than ever in 2025 and beyond. Here at Yuki Homes, we have a licensed construction team in Japan that handles all permitting and compliance requirements for our clients, ensuring your renovation is done legally and efficiently.

Disclaimer:
This article is for informational purposes only and does not constitute legal advice. We are not lawyers. For legal guidance related to building permits or property laws in Japan, please consult a qualified legal professional or a licensed architect familiar with Japanese regulations.

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