The method
Before using the result
- Use the denominator appropriate to this tool: gross wall, floor or gross building area. This is a geometric ratio, not daylight performance or statutory compliance.
Worked examples
These original training examples illustrate the method for First-Class Architect Exam 一級建築士 (Gakka Written + Design Drafting). Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.
1. Worked example
Calculate geometric opening ratios room by room. Keep the result separate from effective daylight factors and any jurisdiction-specific statutory coefficients.
Supplied room opening areas
| Location | Room floor area (m²) | Opening/glazing area (m²) |
|---|---|---|
| Room A | 25 | 4 |
- Combined ratio = Σnumerator / Σdenominator = 4 / 25 × 100%.
- Combined area ratio: 16 %
- Total denominator area: 25 m²
- Total numerator area: 4 m²
2. Comparison example
Compare a different supplied condition using the same method. For Kenchikushi Exam, the important check is that the input meaning, units and method assumptions still match the problem.
Supplied room opening areas
| Location | Room floor area (m²) | Opening/glazing area (m²) |
|---|---|---|
| Room B | 30 | 6 |
- Combined ratio = Σnumerator / Σdenominator = 6 / 30 × 100%.
- Combined area ratio: 20 %
- Total denominator area: 30 m²
- Total numerator area: 6 m²
Check your understanding
1. Which relationship is used?
Area ratio = numerator area / gross denominator area × 100; combined ratio uses summed areas.
2. Which assumption should you check first?
Use the denominator appropriate to this tool: gross wall, floor or gross building area. This is a geometric ratio, not daylight performance or statutory compliance.
3. How should you verify a different unit system?
Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.
Continue with the matching exam topic
This tool connects to First-Class Architect Exam 一級建築士 (Gakka Written + Design Drafting) free practice. Work through a question independently, then use the calculation steps to identify where your method differs. The tool stays free whether or not you choose paid preparation.