| --- |
| license: cc-by-4.0 |
| language: |
| - en |
| - ja |
| tags: |
| - construction |
| - cost-estimation |
| - fraud-detection |
| - consumer-protection |
| - japan |
| - residential-renovation |
| - llm |
| - nlp |
| size_categories: |
| - n<1K |
| pretty_name: Japan Construction Cost Database |
| --- |
| |
| # Japan Construction Cost Database (JCCDB) |
|
|
| An openly licensed structured dataset linking residential construction plan-level pricing, contractor-size-tier margin ranges, and fraud-detection patterns for the Japanese market. |
|
|
| ## Overview |
|
|
| JCCDB is the first openly licensed dataset of its kind for Japan's ¥7.35-trillion-per-year residential renovation market. It comprises: |
|
|
| - **87 construction plans** across 7 renovation categories (roof, termite control, water heater, window, bathroom, kitchen, electrical) |
| - **88 fraud-detection patterns** annotated by severity |
| - **4-tier contractor-size margin ranges** (sole proprietor → mid-size → major → national chain) |
| - Pricing grounded in 2026 Kanto-region trade-price data and 30 years of construction management experience |
| - Quarterly recalibration via Bank of Japan CGPI integration |
|
|
| ## Use Cases |
|
|
| - Training and evaluating LLM-based cost estimation systems |
| - Consumer-protection research and fraud detection benchmarks |
| - Cross-country comparative construction-economics analysis |
| - Real-world LLM application case studies in non-English markets |
|
|
| ## Citation |
|
|
| ```bibtex |
| @misc{oga2026jccdb, |
| title = {Japan Construction Cost Database: An Open Dataset for LLM-Based Cost Estimation and Fraud Detection in Residential Renovation}, |
| author = {Oga, Toshikatsu}, |
| year = {2026}, |
| doi = {10.31224/7007}, |
| url = {https://engrxiv.org/preprint/view/7007} |
| } |
| ``` |
|
|
| ## Links |
|
|
| - **Paper (engrXiv):** https://doi.org/10.31224/7007 |
| - **Original dataset (Zenodo):** https://doi.org/10.5281/zenodo.20019573 |
| - **Code (GitHub):** https://github.com/ogasurfproject-jpg/japan-construction-cost-database |
| - **Author ORCID:** 0009-0000-9180-903X |
| - **Service (HORIZON SHIELD):** https://shield.the-horizons-innovation.com |
|
|
| ## License |
|
|
| Creative Commons Attribution 4.0 International (CC-BY 4.0). Free for commercial and non-commercial use with attribution. |
|
|
| ## Author |
|
|
| Toshikatsu Oga — The HORIZ音s Co., Ltd. (Japan) |
| 30 years in residential construction (carpenter → site supervisor → CM → AI engineer) |
