Wooden or Reinforced-Concrete Houses? Lifespan, Earthquake Resistance, and Prices in Japan

3. Lifespan and Tax Depreciation (法定耐用年数): 22 Years vs. 47 Years

When discussing the lifespan of homes in Japan, it is important to distinguish between two concepts: the statutory depreciation period (法定耐用年数 - hotei taiyo nensu) and the actual usable lifespan (実質耐用年数 - jisshitsu taiyo nensu).

Statutory lifespan (Tax depreciation):
- Mokuzo (Wooden house): 22 years
- S造 (Heavy-gauge steel frame > 4mm): 34 years
- RC / SRC (Reinforced concrete): 47 years

What Tax Depreciation Periods Mean for Your Finances

• For owner-occupiers: The remaining statutory lifespan directly affects the term of a mortgage (住宅ローン - jutaku ron). Banks often use 47 years - the building's age for RC houses and 22 years - the building's age for wooden houses when calculating the maximum loan term. If you buy a 20-year-old wooden house, obtaining a 30-35-year mortgage will be considerably more difficult than for an RC house of the same age.
• For property investors: The short depreciation period for wooden houses (22 years) allows owners to record higher annual depreciation expenses (減価償却費 - genka shokaku hi), significantly reducing income tax (節税 - setsuzei) during the early years of ownership.

Actual Lifespan

In reality, wooden houses do not simply “break down after 22 years,” as many people mistakenly believe. With regular termite prevention (防蟻処理 - bogi shori) and waterproofing every 10 years, modern wooden houses can remain in good condition for 40 – 50 years. Reinforced-concrete RC houses, meanwhile, have an actual structural lifespan of 60 – 100 years.

---

4. Earthquake and Fire Resistance: Are Wooden Houses Really Dangerous?

Japan is well known for earthquakes and fires. However, its building regulations are extremely strict:

Earthquake Resistance (耐震性 - Taishin-sei)

All homes built in Japan after June 1981 must comply with the New Earthquake Resistance Standards (新耐震基準 - shin-taishin kijun). Wooden houses, in particular, were subject to additional stringent technical standards in 2000. These standards ensure that a house will not collapse or pose a threat to human life even during shaking measuring 6+ to 7 on the Japanese seismic intensity scale (震度6強〜7).

Modern wooden houses use engineered laminated timber technology (CLT) together with seismic dampers (制震ダンパー - seishin danpa), achieving the highest earthquake-resistance rating, 耐震等級3 (Taishin Toki 3) — with 1,5 times the load-bearing capacity required by the minimum legal standard.

However, when it comes to shaking during light to moderate earthquakes, the greater mass and rigidity of RC houses generally make them feel less swaying than wooden houses.

Fire Resistance (耐火性 - Taikasei)

• RC/SRC: Concrete is completely non-combustible. Concrete walls are highly effective at preventing fire from spreading from neighboring homes.
• Mokuzo: Natural wood burns easily, but modern wooden houses are often built to the quasi-fire-resistant construction standard (省令準耐火構造 - shorei jun-taika kozo). By lining the inside of walls and ceilings with fire-resistant gypsum board (石膏ボード - sekko bodo), the spread of fire can be delayed for 15–45 minutes, providing enough time to evacuate. Wooden houses meeting this standard may also qualify for up to a 50% reduction in fire-insurance premiums (火災保険料 - kasai hoken ryo).

---

5. Soundproofing and Thermal Insulation: The Real-Life Living Experience

This is the factor that most directly affects your family's day-to-day life.

Soundproofing (遮音性 - Shaonsei)

• Reinforced concrete (RC): The clear winner. Solid concrete walls measuring 15–20 cm thick block most everyday noise, conversations, and television sounds from neighboring homes.
• Wooden houses (Mokuzo): Less effective at blocking sound. Low-frequency noises such as footsteps from the floor above, toilet-flushing sounds, and slamming doors can easily travel through wooden floors and walls. If you rent a Mokuzo apartment, you may have problems with neighbors if you have children who run and play indoors.

Thermal Insulation and Humidity Control (断熱性・調湿性)

• Wooden houses (Mokuzo): Wood conducts heat less readily than concrete and can “breathe” naturally, absorbing moisture in humid weather and releasing it when the air is dry. In summer, wooden houses accumulate less heat. In winter, when combined with spray-applied urethane insulation or fiberglass (グラスウール - gurasu uru), as well as 2-3-layer glazing (複層ガラス / 三重ガラス), wooden houses can be very warm and comfortable.
• Concrete (RC): Concrete retains heat for a long time. In summer, without air conditioning, heat radiating from the concrete can make rooms extremely hot. In winter, concrete feels icy cold, and condensation may form on walls and windows (結露 - ketsuro) if ventilation is inadequate.

---

6. Overall Comparison Table and Selection Advice

Practical Advice: Which Should You Choose?

1. Choose a wooden house (Mokuzo) if:

   • You want to buy a detached house (一戸建て - ikkodate) with a garden and private parking at a reasonable cost.
   • Your family is not particularly sensitive to surrounding noise, or you are buying a detached house that does not share walls with other homes.
   • You are an individual property investor looking to optimize cash flow, recover your investment quickly, and take advantage of short-term tax depreciation (減価償却).

2. Choose reinforced concrete (RC/SRC) if:

   • You value peace and privacy and do not want to be disturbed by neighbors' noise, making it especially suitable for a condominium apartment マンション.
   • You want to buy a property that retains its value well and makes it easier to obtain a long-term 35-year mortgage (住宅ローン), even if the property is 10-15 years old.
   • You enjoy living in central areas near train stations, on higher floors with attractive views and a high level of security.

---

7. Frequently Asked Questions

Q. If I buy a used wooden house in Japan that is more than 22 years old, does it lose all its value?

Not entirely. After 22 years, the book value of the wooden structure itself may fall to nearly 0 JPY in accounting terms, but the land value (土地価格 - tochi kakaku) may remain stable or increase depending on the location. You still own the entire plot of land and can demolish and rebuild, or renovate it for continued personal use or rental.

Q. Can I get a 35-year mortgage (住宅ローン) to buy a wooden house in Japan?

Yes, if it is a 100% newly built wooden house (新築 - shinchiku). Japanese banks are willing to offer loans of up to 35 years for new wooden houses. However, if it is a used wooden house (中古 - chuko) that is more than 15-20 years old, the bank may shorten the loan term or require additional collateral.

Q. Approximately how much does periodic maintenance cost for a wooden house?

Typically, every 10–12 years, a wooden house needs exterior walls repainted (外壁塗装 - gaiheki tosou), roof waterproofing renewed, and termite prevention treatment (防蟻処理 - bogi shori) carried out. Each comprehensive maintenance cycle costs approximately 1.000.000 – 1.500.000 JPY (~165 – 250 million VND).

Q. Does renting a wooden apartment (Mokuzo apato) cost more in air-conditioning electricity than renting an RC apartment?

For older wooden homes built before 2000, poor insulation can increase winter/summer electricity bills by 20-30%. However, newer wooden apartment buildings constructed in recent years with insulated laminated glass and thick fiberglass-insulated walls do not have dramatically different energy costs from RC buildings.

---

Summary & Further Reading

The choice between a wooden house (Mokuzo) and a reinforced-concrete house (RC/SRC) depends largely on your budget, intended use—living or investment—and lifestyle. Wooden houses offer a warm, cozy living environment and reasonable initial ownership costs, while concrete houses provide greater structural strength, superior soundproofing, and stronger long-term asset value.

To gain more useful knowledge for building a stable life and career in Japan, you can also explore these related articles:

• Get practical updates on daily life and residency procedures at OlaChill Blog.
• Learn more about buying property through the detailed guide Guide to Buying a House in Japan.
• If you need travel-service advice or want to explore Japan on a weekend trip with your family, check out the list of Day Tours from Tokyo.
• Visit the OlaChill homepage to stay up to date with the latest information for the Vietnamese community in Japan!

---