GoCodebook vs Zoneomics vs National Zoning Atlas
Three tools, three different jobs
“Zoning software” covers products that barely overlap. Zoneomics sells zoning data at national scale with an API. The National Zoning Atlas publishes standardised zoning research across 24 states. GoCodebook reads the adopted code text for one state and answers questions with the citation attached. Pick by which of those you actually need — this page tells you when the answer is not us.
Quick comparison
Read down the columns, not across the rows — a “No” here usually means “not what this tool is for.” Figures are from each project’s own site, August 2026.
| Capability | GoCodebook | Zoneomics | National Zoning Atlas |
|---|---|---|---|
| Full verbatim code text to read | Yes | No | No |
| Building, fire, plumbing & energy codes (Title 24) | Yes — 13 parts | Zoning only | Zoning only |
| Zoning districts & permitted uses | Yes | Yes | Yes |
| Plain-English answer with a citation to the section | Yes | Reports | No |
| Reconciles state code with local amendments | Yes | No | No |
| National coverage | California only | 23,500+ cities | 24 states |
| Parcel-level zoning lookup | Yes | 100M parcels | District level |
| API / bulk data | No | Yes | For research |
| Standardised categories for cross-state comparison | No | Partial | Yes — its purpose |
| Certified zoning reports for lenders | No | Yes | No |
| Free to use | Free tier | Commercial | Nonprofit |
Which one you want
Pick Zoneomics when you need breadth or an API
A commercial zoning-data platform covering 23,500+ cities and 100 million parcels, with an API, bulk queries and zoning reports up to certified letters. If your work spans states, feeds a model, or needs a report a lender will accept, that is what it is built for — and GoCodebook does none of it.
Pick the National Zoning Atlas for research and policy
A 501(c)(3) project of Land Use Atlas, Inc., housed at Cornell's Legal Constructs Lab and led by Prof. Sara Bronin, digitising zoning across 30,000+ jurisdictions in 24 participating states. Its value is that every jurisdiction is coded into the same standardised categories, which is what makes cross-state comparison possible at all. If you are studying zoning rather than building under it, start there.
Pick GoCodebook when the question is what the code actually says
Not a zoning dataset — a reader over the adopted text, California only. 540 jurisdictions, 794 documents and 289,000+ sections, including all 13 parts of Title 24. Ask a question and get a plain-English answer with a link to the section it came from, so you can read the sentence yourself.
Where the difference actually shows up
Zoning data vs the whole code
A zoning attribute tells you a lot is R-2. It does not tell you the fire separation to the property line, the egress window your bedroom needs, or the Title 24 energy requirement for the addition. Those live in the building code, and are the questions that stop projects at plan check.
A field vs a sentence
Structured data is an answer with the reasoning removed. When a plan checker disagrees, you need the provision. Every GoCodebook answer links to the section, and the section renders in full.
State plus local, reconciled
California sets a floor and cities amend it. A district label alone cannot express "the state caps what the city may require, and this city requires less." That reconciliation is the work.
Depth bought with breadth
One state, read closely, instead of fifty summarised. That is a real trade — it is why the recommendations above send you elsewhere for anything outside California.
Frequently asked questions
Is GoCodebook a Zoneomics alternative?
Only for part of what Zoneomics does. Zoneomics is a zoning-data platform: structured attributes across 23,500+ cities, an API, bulk access and zoning reports including certified letters. GoCodebook is a California-only reader over adopted code text — zoning ordinances plus all 13 parts of Title 24 — that answers questions in plain English and cites the section. If you need national coverage, an API or a certified report, Zoneomics is the right tool and GoCodebook does not replace it.
How is this different from the National Zoning Atlas?
Different purpose. The National Zoning Atlas is a nonprofit research project — Land Use Atlas, Inc., housed at Cornell's Legal Constructs Lab — that codes zoning across 30,000+ jurisdictions into standardised categories so researchers and policymakers can compare places. It is built for studying zoning. GoCodebook is built for working under it in one state: the verbatim text, the local amendments, and an answer you can cite at plan check.
Why only California?
Because the depth is the product. 540 jurisdictions, 794 documents, 289,000+ sections and every part of Title 24, with local amendments reconciled against the state code. Reproducing that nationally is a different amount of work than adding rows to a table, and doing it badly is worse than not doing it.
Can I use them together?
That is the common case. Zoneomics or a parcel dataset tells you the district and the lot; GoCodebook tells you what the adopted text requires once you are inside it. They answer different halves of the same project question.
Reading the code, not just the label
If your question is what the adopted California text requires — and you want the section to read yourself — that is what GoCodebook is for.
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