Zoning Concepts Atlas

Overview

Zoning concepts that appear across every city page. Each concept has its own canonical explainer here, so city research can just link to the definition instead of re-explaining it.

This is a scaffold — the initial 5 concepts were selected because they appear in 20+ city pages across the corpus. Concepts are added as city research surfaces new terms that warrant a canonical explainer.

Tracked concepts

EDITORIAL

Zoning Code Types

Euclidean, Hybrid, Form-Based, No-zoning, and the systems that layer on top (Incentive, Inclusionary, Overlay, Specific Plan). Example cities are V2-only.

TOD

Transit-Oriented Development

Dense, mixed-use development concentrated within walking distance of high-frequency transit — typically a ½-mile radius around a rail station or BRT stop.

CEQA

California Environmental Quality Act

California's 1970 environmental-review statute — requires an EIR for any discretionary project whose physical impact isn't demonstrably insignificant.

RHNA

Regional Housing Needs Allocation

California's state-driven housing target system — every 8 years each city gets assigned a number of units it must zone for across four income bands.

PUD

Planned Unit Development

A site-specific zoning mechanism that lets a developer negotiate custom bulk and use standards in exchange for master-plan commitments.

Floodplain Overlay

Floodplain Overlay District

The city-level zoning layer that implements FEMA's Special Flood Hazard Area rules — elevation, floodproofing, and substantial-improvement triggers.

How this fits the pipeline

City research now stops re-explaining what TOD / CEQA / floodplain overlays are. It just records the local applicability (does this city apply it? under what ordinance?) and links to the concept page. This cuts profile JSON size, reduces concept drift, and makes audits one-click (check the concept page once, not 96 city profiles).