Glossary15 terms

Zoning & Land Use

Zoning code, Unzoned, Upzoning / downzoning and 12 more, each with its own link.

Zoning code: The legal designation that defines what can be built on a parcel. Common residential codes include R-1 (single-family), R-2 (duplex), R-3 (multi-family). Commercial codes include C-1 (neighborhood), C-2 (general). Mixed-use codes include MU and PUD. Each code carries a full set of development standards: permitted uses, setbacks, height, FAR, lot coverage.
Unzoned (NZ / UZ): A parcel where no local zoning designation applies. Two sub-types. NZ (No Zoning) — the municipality does not have zoning as a matter of policy; Houston is the canonical example, where development is governed by deed restrictions (CCRs) instead. UZ (Unzoned) — the parcel sits outside zoning jurisdiction entirely, typically federal, tribal, or military land. Buildability tags both; the distinction matters because NZ parcels are not zoned but are still bound by deed restrictions (CC&Rs), building codes and subdivision rules, while UZ parcels answer to the federal, tribal or military authority that holds them.
Upzoning / downzoning: Policy changes to a parcel or district's zoning designation. Upzoning increases allowed density or intensity — e.g., R-1 single-family to R-4 multifamily — typically to support housing supply. Downzoning reduces it — e.g., C-2 commercial back to R-1 — typically to preserve neighborhood character. Both are politically contentious, trigger public hearings, and in California are subject to CEQA review. State preemption laws (SB 9, AB 2011) effectively upzone large swaths of the state without requiring a local rezoning vote.
Setback: The minimum required distance between a building and the property boundary lines. Typical single-family setbacks: 20 feet front, 5 feet side, 20 feet rear. Setbacks define the buildable envelope — the area of the lot where construction is legally permitted.
FAR (Floor Area Ratio): The ratio of a building's total floor area to the lot area. A FAR of 0.5 allows total floor space equal to half the lot area. A FAR of 2.0 allows twice the lot area, typically achieved through multiple stories. FAR is the single most important number for developers because it determines project density and economics.
Lot coverage: The maximum percentage of a lot that can be covered by structures (the building footprint). A lot coverage limit of 0.4 on a 10,000 sqft lot allows up to 4,000 sqft of footprint. Lot coverage is distinct from FAR — coverage governs the ground footprint, FAR governs total floor area across all stories.
ADU (Accessory Dwelling Unit): A secondary housing unit on a single-family lot. Common types: detached ADU (new structure in the backyard), attached ADU (addition to the main house), garage conversion. Typical maximum size: 800-1,200 sqft. State laws in California (AB 68), Oregon (HB 2001), and Washington (HB 1110) force most cities to allow at least one ADU on most single-family lots.
JADU (Junior Accessory Dwelling Unit): A smaller variant of an ADU created within an existing single-family house, typically by converting a bedroom and adding a kitchenette. JADUs are usually limited to ~500 sqft and may share a bathroom with the main house. They are generally easier and faster to permit than detached ADUs but offer less privacy.
Permitted use: A use that is allowed by-right under the zoning code without requiring a special permit, conditional use permit, or variance. If your intended use is permitted in the parcel's zoning district, you can apply for building permits without going through a discretionary approval process.
By-right development: A project that complies with all applicable zoning, building, and land-use regulations without requiring any discretionary approvals — no variance, no Conditional Use Permit, no public hearing. By-right projects proceed directly to ministerial building-permit review, which typically takes weeks instead of months. By-right status is the fastest, cheapest, lowest-risk path to entitlement and is the outcome that streamlining laws like SB 9, SB 35, and AB 2011 create for qualifying projects.
Ministerial vs discretionary: Two categories of local approval. Ministerial actions are non-discretionary — once the applicant meets objective standards, the approval must be issued. Exempt from CEQA / NEPA review. Discretionary actions require subjective judgment from staff or a hearing body (planning commission, city council) and trigger full environmental review. California's SB 9 and SB 35 convert specific project types from discretionary to ministerial, dramatically accelerating entitlement.
Conditional use: A use that is allowed in a zoning district only with a special permit (sometimes called a Conditional Use Permit or CUP). Conditional uses require a public hearing and approval from the planning commission. Common examples: drive-throughs in commercial zones, religious institutions in residential zones, group homes.
CUP (Conditional Use Permit): The formal permit required for a Conditional use — a use allowed in a zoning district only with discretionary approval from the planning commission after a public hearing. CUPs add a public hearing, an application fee set by each city's fee schedule, and meaningful public-comment risk; the time and fee vary by jurisdiction and are not on record here. Conditions attached to CUP approval (hours of operation, parking, landscaping, noise limits) are binding on the property and run with the land — they survive a sale to a new owner.
Overlay district: An additional layer of zoning regulations placed on top of the base zoning. Common overlays: historic preservation (limits exterior modifications), coastal commission (requires CCC approval), flood hazard (FEMA elevation requirements), wildfire WUI (fire-resistant materials), airport influence (height limits), hillside (slope and grading limits). Overlay districts often add significant cost and timeline to a project.
Density bonus: State and local programs granting developers the right to build more units than base zoning permits in exchange for providing below-market-rate (BMR) housing. California's Density Bonus Law (Gov Code §65915) grants additional units plus concessions — reduced parking, height waivers, setback relaxations — on a sliding scale tied to the share of affordable units; read the current section for the percentages, which the Legislature has amended repeatedly. Similar programs operate in most urbanized states. Density bonus is typically stackable with SB 35 and AB 2011 streamlining, compounding the unit count on a qualifying parcel.

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