Every jurisdiction is a data pack.
Every rate, tax percentage, statutory holdback, permit fee and code citation lives in a JSON data pack — a plain text file you can open. Every figure prints the authority it came from, so you can check it instead of trusting it.
That means changing jurisdiction is a data edit, not a rebuild. Packs are built for any Canadian province or territory, any US state, and any EU country plus the UK and Ireland — sourced and cited to that jurisdiction’s own authorities, and every plan reaches every pack including Field. Jurisdiction is not an upgrade.
| Jurisdiction | Rules | Depth |
|---|---|---|
| Ontario | 105 | baseline |
| British Columbia | 7 | baseline |
| California | 5 | baseline |
| Florida | 16 | baseline |
| New York City | 16 | baseline |
| United States — IRC baseline | 12 | baseline |
| Canada — NBC baseline | 9 | baseline |
| England | 4 | baseline |
baseline — the model-code requirements that jurisdiction adopts unchanged are checked; its own local amendments are not applied yet. The audit tells you which depth you are reading before it shows you a single finding.
Every pack is currently baseline, including Ontario. The tier above it — verified, meaning every rule checked against the authority by somebody other than whoever wrote it — needs a second person, and this codebase has had one committer throughout its history. Ontario, British Columbia and California were marked verified until 29 August 2026, when we could not evidence that second check and demoted them. A pack goes back to verified when there is a name and a date on the check, and only then.
Rate, tax and cost data runs wider than the code rules do — 43 cities across Canada, the United States and Europe, 19 of them European. England ships a code pack today (Approved Document K); an EU-country code pack is authored on request, and we would rather say so here than let you discover it.
The same check gives a different answer in every market.
This is what a jurisdiction pack is for. Draw one private stair and run it under five different packs: the geometry does not change, the verdict does. Every figure and citation below is read out of the shipped rule files.
| Jurisdiction | Max riser | Min going / tread | Min clear width |
|---|---|---|---|
| Ontario OBC 2025, Art. 9.8.4.1 |
200 mm | 235 mm | 860 mm |
| Canada — NBC baseline NBC 2020, Div. B 9.8.4.1 / 9.8.2.1 |
200 mm | — | 860 mm |
| United States — IRC baseline IRC 2021, R311.7 |
196 mm (7¾″) | 254 mm (10″) | 914 mm (36″) |
| California CRC 2022, R311.7.5 |
196 mm (7¾″) | 254 mm (10″) | 914 mm (36″) |
| England Approved Document K (2013), Table 1.1 |
220 mm | 220 mm | — |
A stair that passes in London fails in Toronto by 20 mm a riser, and one that passes in Toronto fails in Sacramento by 4. Point the audit at a jurisdiction and it reports under that jurisdiction’s article numbers, so the finding is something you can hand to a plan examiner, instead of a note saying the stair looks steep.
