How to Select Earthquake-Resistant Properties in Japan: Plaza Homes Guide

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If you’re planning to rent or buy a property in Japan, especially in Tokyo, earthquake safety may be a primary concern as you evaluate different options. For buyers and investors, the decision also has financing and tax implications beyond safety and long-term peace of mind. Fortunately, Japan has some of the world’s strictest building standards. Understanding them will help you make informed decisions when choosing a home.

This guide, created in collaboration with Plaza Homes, gives a brief overview of how to evaluate earthquake-resistant buildings, including year of construction, construction type, seismic grade and neighborhood risks. Plaza Homes is a bilingual real estate agency with a 50-year-plus track record of helping expats rent, buy and sell property in Tokyo and is a long-time partner of Real Estate Japan.

Why the construction year matters

When evaluating a property for earthquake resistance, one of the most important details is the year constructed. Japan updated its Building Standard Act in 1981, introducing the New Anti-Seismic Design Standard (colloquially referred to as shin-taishin in Japanese).

• Pre-1981 (Old Standard / kyu-taishin):
  Before June 1981, standards required that buildings would not collapse during an earthquake of JMA seismic intensity scale 5+.
• Post-1981 (New Standard / shin-taishin):
  After June 1981, standards were tightened to ensure that buildings do not collapse during an earthquake of JMA seismic intensity scale 6+ to 7 and are only minimally damaged by an earthquake of JMA seismic intensity scale 5+. 

If you’re considering a condominium completed between 1981 and 1983, however, it’s wise to check compliance with the new standard, as some early post-1981 buildings may still follow older criteria.

Another good tip here is that municipal offices or your real estate agent can help confirm the certification date of the building.

Financial and tax implications

Choosing a building under the post-1981 standard has tangible financial benefits:

• Mortgage Approval: Lenders prefer post-1981 buildings; older structures may face stricter conditions for loan approval.
• Housing Loan Tax Deduction: Buildings meeting new standards, or with a seismic certificate, are more likely to qualify. The Housing Loan Tax Deduction is the system in which 0.7% of the loan balance at the end of the year is deducted from your income tax for the period up to 13 years when you take out a housing loan for building a new house, buying a house, expanding, or renovating it, etc.
• Other Tax Incentives: Post-1981 or certified buildings may benefit from reduced property acquisition and registration taxes.

Even if you’re renting, knowing the standard helps you understand long-term value and potential tax advantages if you buy later.

Constructions types: what they mean for earthquake safety

Real estate listings also indicate a building’s structural type, which influences how it behaves during quakes:

• Wood: A versatile and widely used material, forms the core structure of many detached houses in Japan. The post and beams generally provide the essential support.
• Steel Frame (S): Steel beams and columns provide strong load-bearing support. Often used in large apartment buildings. 
• Reinforced Concrete (RC): Concrete reinforced with steel rebar; durable and common in urban apartments. The steel bars resist stretching forces, and the concrete handles compressive forces.
• Steel Reinforced Concrete (SRC): Construction uses iron bars and beams filled with concrete to provide excellent seismic resistance, strength, and durability; strongest option for high-rise towers.

RC and SRC are generally preferred for multi-story urban living because they combine strength and stability.

Understanding seismic grade

When you are evaluating a building for earthquake resistance, it is also important to understand the concept of Seismic Grade, which was introduced under the Housing Performance Labeling System (2000). The system provides a quick way to assess earthquake resistance:

• Grade 1: Meets the Building Standard Act requirements. Minimally damaged in intensity 5+ quakes; does not collapse even in earthquakes rated 6+ to 7. However, they may need rebuilding after a 6+ or higher quake.
• Grade 2: 1.25× resistance of Grade 1. Buildings may be damaged in 6+ to 7-intensity quakes, but the damage is generally repairable. Can qualify to be certified as “Long-life quality housing,” which offers various tax incentives.
• Grade 3: 1.5× resistance of Grade 1. Required for essential service buildings like fire stations and police; may sustain minor damage in 6+ to 7-intensity quakes but is typically repairable.

Seismic Grade is a quick way to assess a building’s earthquake resistance. Image: Plaza Homes

Higher seismic grades can make it easier to secure mortgages, qualify for tax deductions and may even affect long-term resale value.

Not all houses have this certification, however, because the system is voluntary, so ask the builder, developer or agent if it’s available.

Earthquake-Resistant, Damping, and Seismic-Isolation Structures

The next thing to consider is the actual earthquake-resistant technology used in the building. Japanese buildings are designed using three main approaches to manage seismic forces:

1. Earthquake-Resistant Structure (taishin, in Japanese):
   The building’s frame and walls are reinforced to resist shaking directly. Most detached houses use this method. Buildings can be categorized into two types: rigid structures, which are constructed rigidly to prevent collapse, and flexible structures, which flexibly bow to spread the force of seismic motions.
2. Damping Structure (seishin):
   These incorporate dampers or shock absorbers to reduce vibration. Damping structures help minimize building sway and structural damage, improving comfort during quakes and reducing seismic intensity by 70% to 80% compared to earthquake-resistant buildings. Common in modern mid-rise and high-rise apartments.
3. Seismic-Isolation Structure (menshin):
   The building is physically isolated from ground movement using special devices installed at the foundation. When the ground shakes, the building moves far less. This system significantly reduces interior shaking and protects furniture, but it is usually more expensive and found in high-end residential towers or essential facilities.

The three main types of earthquake-resistant technology used in Japan. Image: Plaza Homes

Understanding these three structural approaches can help you choose a building that matches your comfort, safety and budget priorities.

Safer and higher-risk areas in Tokyo

Earthquake risk is also affected by ground conditions:

• Safer Areas: Elevated zones like the Musashino Plateau have firmer soil and lower liquefaction risk. Many western and central residential neighborhoods fall into this category. These include Chiyoda Ward, Minato Ward, and Shibuya Ward.
• Higher-Risk Areas: Reclaimed land along Tokyo Bay, river-adjacent districts, or areas with dense older wooden homes may shake more and face liquefaction. More specifically, these areas are considered high risk: southern Adachi Ward, Arakawa Ward, Eastern Taito Ward, Western Katsushika Ward, Sumida Ward and Northern Koto Ward.

If you prioritize safety, combine location awareness with a building’s structural and seismic grade.

How to evaluate a property

In summary, when checking a listing or visiting a property, use this checklist as a starting point:

1. 1. Construction year: Look for post-1981 buildings unless older ones have verified seismic retrofitting.
   2. Structure type: Confirm whether it’s wooden construction, steel, RC or SRC. Consider height and number of floors.
   3. Seismic grade: Ask for certification; higher grades are safer and can offer tax/ and finance benefits.
   4. Earthquake-resistant technology: Know the three types and include them in your decision making process.
   5. Neighborhood risk: Research ground conditions and urban development history.
   6. Retrofitting or reinforcement: Especially for pre-1981 buildings, ask about upgrades.

These simple steps help you make safer, more informed choices.

However, there really is no substitute for working with a qualified local agent. It is best to ask your real estate agent for clarification if any details are missing. For expats navigating Tokyo’s property market, Plaza Homes offers bilingual support and expert guidance to find a home that’s both safe and comfortable.

Visit Plaza Homes to see a list of featured properties for sale with high earthquake-resistance.

Plaza Homes

Plaza Homes is one of the leading bilingual real estate brokerages in Tokyo, with over 55 years of experience helping foreigners buy and sell real estate in Japan. If you are considering buying or selling a property in Tokyo or looking for rental accommodation, please contact them below to get started!