Zoning & entitlements
Overlay zone
A supplemental zoning district layered over base zoning that adds or modifies standards — historic, coastal, hillside, airport, or transit-oriented.
Definition
An overlay zone superimposes additional regulations on one or more underlying base districts: the base zone keeps governing use and density except where the overlay modifies them. Overlays are adopted and amended like any other district regulation under the state zoning law.
They cut both ways — historic, hillside, airport-safety and coastal overlays typically add review layers or tighter standards, while transit-oriented and housing-opportunity overlays often grant extra density, height, or streamlined process above the base zone.
Why it matters in an underwrite
Overlays are a classic diligence miss: the base zone supports the pro forma while an overlay quietly adds a discretionary certificate, a stricter height plane, or extra findings. The reverse miss costs money too — an incentive overlay the underwrite never claimed. Pull the full zoning stack (base district plus every overlay) and read the overlay chapters themselves before pricing land.
Sources & related guides
See also
See the term in the law itself
Read the controlling text in the Code Library, or ask the AI how it applies to your project.
Last reviewed 2026-07-29. General information, not legal advice.