DocsData & methodology
The Zoning Atlas
The Atlas is the part of Buildability nobody else sells in machine-readable form: what a lot can hold by right, with every number quoted from the section of the zoning code that says it. A number with no sentence behind it is never stored.
Two questions, two sources
Zoning answers come in two layers, and the product keeps them apart.
- Which district is this lot in? Read from the city’s or county’s own zoning GIS layer at the parcel. Buildability can name the district today in 39 cities, and parcel records carry a district name in many more places.
- What does that district allow? Read from the ordinance itself into the Atlas: heights, setbacks, lot minimums, coverage, density, uses. This is the slower, deeper read, and coverage grows city by city.
Knowing the district without its standards is common. In that case the report names the district, says the standards haven’t been read yet, and the Score’s zoning factor is left out rather than guessed.
What the Atlas stores
Each district carries up to 22 cited standards. Every one is a value, the verbatim quote it came from, the section number, the source URL, and the date the code was read.
| Group | Standards |
|---|---|
| Height | Maximum height (ft), maximum stories |
| Intensity | Maximum FAR, maximum lot coverage (%), maximum floor area, minimum open space (%) |
| Lot | Minimum lot size, width, depth and frontage |
| Setbacks | Front, side, rear, street side, accessory structure |
| ADUs and accessory | Maximum ADU size and height, maximum accessory height |
| Use and other | Allowed uses, parking per unit, minimum dwelling size, maximum fence height |
Beyond the numbers, the Atlas keeps verbatim passages on 18 topics where the qualifier matters as much as the figure: use rules, height, setback, lot and density qualifiers, process triggers, measurement definitions, ADUs, accessory structures, parking, short-term rentals, home occupations, design review, overlays, tree protection, subdivision and nonconforming uses.
The verbatim-quote rule
A language model can propose a reading of a code; it never decides one. Every value goes through the same check before it is stored:
Propose
A reader proposes a value with the exact sentence it came from and the section number.
Verify
Code checks that the quote appears in the source document, after normalizing typography and whitespace. Quotes shorter than 12 characters fail.
Grade
Quote found and the number in it: extracted. Quote found without the number: partial. Quote not found: declined.
Store
Only extracted values are stored. A partial or declined read is never shown as a standard.
Reading code respects the source: robots.txt is enforced with no override, and the reader identifies itself honestly as BuildabilityBot. A codifier that refuses us is not read.
Draft and confirmed reads
A read stays a draft until the city’s own staff confirm it. Confirmation records a date and never changes a number. Only a confirmed district shows the “Per the City” mark, with the line “the city’s own staff confirmed these standards on” and the date. Everywhere else the standard shows its quote and section, and you can check them yourself.
The buildable envelope
Where a district’s standards are read and the lot’s real outline is on record, the report fits the envelope to the lot:
- Lot area, buildable footprint, floors and maximum buildable square feet
- Maximum units and maximum height
- The binding constraint: FAR, height, coverage, density, use, setbacks or a dwelling cap
- Whether units come from a rule in the code or from massing (about 950 sq ft a unit), and how setbacks were applied
- A confidence (verified, estimated, or limited by an overlay) and a list of what is still unknown
The envelope exists only where a district’s rules have been read. It is never extrapolated from a neighbouring city or a typical district.
Coverage
Coverage changes every week, so these docs don’t print a count. The live ledger is buildability.us/atlas: for every jurisdiction read, its districts, cited standards, passages, the date last read, the source, and how many districts the city has confirmed. It also lists every city where we can name the district.
A city can hand us its code directly and confirm the read through its city account. See For cities.
Didn’t find it? The Help Center answers account and billing questions, and Geo answers questions about a specific parcel inside the app.