As natural disasters occur more frequently, steel-frame homes are drawing attention for their durability and earthquake resistance. This article explains the advantages and disadvantages of steel-frame homes and the key points for choosing the right home builder.
What are the advantages and disadvantages of steel-frame homes?
Advantages
- Steel is resistant to corrosion and offers high durability
- Excellent earthquake resistance based on structural calculations
- Open floor plans are possible because there are fewer constraints from load-bearing walls
- Future renovations are relatively easy
Disadvantages
- Costs are higher than for wooden homes
- The building is heavier, so ground reinforcement may be required in some cases
- Ventilation and insulation tend to be inferior to wooden construction
What are the four key points in choosing a home builder?
1. Type of steel frame (lightweight vs. heavyweight)
Lightweight steel is less than 6 mm thick and suited to detached houses and apartments, while heavyweight steel is 6 mm or more and suited to buildings and apartment complexes of three stories or more.
2. Structural type (rigid frame vs. post-and-beam)
Steel rigid-frame construction secures strength through welding and supports wide, open layouts. Steel post-and-beam construction uses pinned joints and is suited to low- and mid-rise buildings.
3. Use earthquake resistance grade 2 or higher as a benchmark
If a home meets earthquake resistance grade 2 or higher, it qualifies for the standard of a "long-term excellent housing" property, making it eligible for preferential treatment on home loans and fixed asset taxes.
4. Compare the cost per tsubo
Lightweight steel typically costs 600,000 to 900,000 yen per tsubo, while heavyweight steel typically costs 700,000 to 900,000 yen per tsubo. It is worth comparing this with wooden construction (500,000 to 600,000 yen per tsubo) before deciding.
Major recommended home builders for steel-frame homes
- Hebel Haus：Standardized vibration-control structure, with both lightweight and heavyweight steel options
- Sekisui House：80% factory production rate, using its proprietary "Sheqas" vibration-control technology
- Panasonic Homes：Well regarded for layout flexibility and high airtightness and insulation
- Sekisui Heim：Earthquake resistance grade 3 as a standard specification at lower cost
- Daiwa House：High durability through proprietary earthquake-resistance technology and rust-prevention treatment
- Toyota Home：Highly earthquake-resistant structure with industry-leading 125 mm columns
Frequently Asked Questions (FAQ)
Q. How many years does a steel-frame home last?
The statutory useful life is 19 to 34 years for lightweight steel and 34 years for heavyweight steel, but with proper maintenance, use for more than 50 years is possible.
Q. Are fixed asset taxes high for steel-frame homes?
Because the useful life is longer, depreciation for fixed asset tax purposes is slower than for wooden homes, and a relatively high assessed value tends to remain for a longer period.
Q. How can lower insulation performance be addressed?
Each home builder has developed its own insulation methods. Rather than relying only on catalog specifications, it is advisable to confirm actual comfort levels at a model home.
