Japan Construction Cost Database (JCCDB) v3.1 — 65,520 construction and renovation line items (no prices)

JCCDB is a catalogue of construction and renovation line items used in Japan: item name, category and unit. It contains no prices. Price data lives in a separate layer (souba-db) and is not part of this deposit. Japanese construction estimates are written differently by every contractor, so two quotes for the same job cannot be compared line by line. JCCDB is the shared item catalogue that makes that comparison possible. Composition, as measured 65,520 items total; zero duplicate rows on category + item_name + unit. Verified 13,207 — checked against manufacturer catalogues. Of these, roughly 11,250 came from the v2.0 hand-check and do not carry per-item evidence URLs. The remainder were promoted during the v3.0 and v3.1 verification rounds and those carry per-item evidence URLs in jccdb-v3-provenance.csv (2,243 rows). The two are not the same kind of record, and the distinction is stated here rather than averaged away. Extended 52,313 — matrix-generated combinations (manufacturer x series x size x colour). Individual SKU existence is NOT verified. This tier is kept separate precisely so that the unverified part is not presented as verified. Verified + Extended = 65,520, exactly the total. Retracted 608 — items proven not to exist, removed from the totals and kept in jccdb-v3-retracted.csv with reasons and evidence URLs, so the removal itself can be checked. Categories exist at two granularities: 72 in the CSV category column, 402 in the fine-grained jccdb-v3-schema.json. Both describe the same 65,520 items at different resolutions. Columns: category, item_name, unit. UTF-8 with BOM, quoted CSV. Verifying this without trusting the author The SHA-256 of every published file is listed in JCCDB_v3_1_RELEASE_DECLARATION.md, included in this deposit. The digest of that declaration is appended to the JIDEC public ledger and timestamped into the Bitcoin blockchain through OpenTimestamps. A third party can therefore establish, without asking the author for anything, that these files had these contents at or before the anchored time. Ledger: https://ledger.horizonshield.dev Relationship to the papers The Zenodo record 10.5281/zenodo.20019572 and the engrXiv record 10.31224/7007 are the accompanying papers (PDF), not this dataset. Until this deposit, no item-level snapshot of JCCDB was deposited on Zenodo. The canonical repository is GitHub, with a machine-readable mirror on Hugging Face. 日本語 JCCDB は日本の建設・リフォーム工事の品目名・カテゴリ・単位のオープンデータです。 価格は含みません。65,520品目・重複ゼロ。検証済み 13,207 と、マトリクス生成で 個別の実在確認をしていない Extended 52,313 を分離してあります。非実在と証明された608件は 理由と証拠URL付きで別ファイルに retract しています。全ファイルの SHA-256 はリリース宣言に記載し、 JIDEC 台帳経由で Bitcoin にタイムスタンプしています。Zenodo と engrXiv の既存 DOI は 解説論文であって、データセットではありません。