Concord — Overlay Districts

Last reviewed: July 1, 2026

Overview

Overlay districts in Concord are special zoning layers that sit on top of the city's base zoning and apply additional or different rules for particular places or uses. The Concord Development Code (Title 18) currently contains several overlay chapters that are active citywide or in mapped locations: Airport Overlay (A), Transit Station Overlay (TS), Commercial Cannabis Overlay, and Affordable Housing Overlay (AH). These overlays modify permitted uses, mapping rules, and development or review requirements while generally deferring to the underlying base zoning unless the overlay explicitly controls (see § 18.100.010, § 18.105.010, § 18.110.010, § 18.115.010 ) . For quick context on where overlays fit into local practice, see the Concord zoning & planning overview and Concord Zoning pages linked below.

How to use this page

• Read the district-by-district subsections for the rules that will most likely apply to a parcel.
• Cross-check the mapped overlay(s) on the official zoning map and verify with the planning division (see Checklist).
• Use the internal links to review related permitting and standards (design review, parking, development standards, ADUs) as noted inline.

I link relevant related topics throughout: see the Concord zoning & planning overview, Concord Zoning, Concord Development Standards, Concord Parking, Concord Design Review, Concord ADUs, and the California Building Standards Code.

District-by-district breakdown

### Airport Overlay (A)

• Purpose: The Airport Overlay (A) is established to ensure land use compatibility with airport operations and the Airport Land Use Commission (ALUC) plan. See § 18.100.010 for the purpose statement. § 18.100.030 requires ALUC review where applicable. § 18.100.040 contains the development standards the overlay imposes.
• Where it applies: The code maps the A overlay on parcels affected by airport safety, noise, and height limitations. Confirm whether a parcel is in the overlay using the city zoning map; the Development Code applies the overlay rules to parcels within the mapped area (§ 18.100.020).
• Typical permitted uses / effect on base zoning: Uses allowed in the underlying zoning remain subject to the overlay’s compatibility rules and ALUC requirements; the overlay does not itself create entirely new base uses but restricts or conditions them in the interest of airport safety and compatibility (§ 18.100.040).
• Key dimensional/approval standards (practical summary):
  • ALUC review required for certain entitlements (§ 18.100.030).
  • Height, noise, safety compatibility and other limits are applied per the overlay standards (§ 18.100.040); where airport rules conflict with other local rules, compatibility provisions control.
• Where to check next (practical): If your project is within the A overlay, verify (1) ALUC consistency, (2) height and use restrictions cited in § 18.100.040, and (3) whether any special findings or disclosures are required at permit stage.

### Transit Station Overlay (TS)

• Purpose: The Transit Station Overlay (TS) promotes higher density, pedestrian-oriented, transit-supportive development around BART stations to encourage transit use and walkability (§ 18.105.010).
• Where it applies: A TS overlay may be combined with any base district within one-half mile of a BART station (with specific exceptions noted in the code) (§ 18.105.020).
• Typical permitted uses: Uses permitted in the underlying base zoning remain allowed unless specifically prohibited by the TS chapter; the TS chapter explicitly lists prohibited uses (e.g., surface parking facilities, drive-through retail, certain auto-oriented uses) (§ 18.105.030). Projects must also meet findings demonstrating a balanced mix of residential and commercial uses and a safe pedestrian environment (§ 18.105.030(C)).
• Key dimensional/approval standards:
  • The TS defers to underlying development standards except where it overrides them to require pedestrian amenities, transparency, and reduced surface parking near transit; see the TS development standards (§ 18.105.040) and parking reductions for projects near BART in the parking chapter (CDC 18.160.050).
  • Ground-floor transparency, street-front activation, and prohibitions on surface parking between a building and the pedestrian route to BART are explicitly required for nonresidential/mixed-use projects in TS (§ 18.105.040).
• Practical note: If your site is within a TS overlay, expect pedestrian-oriented site design, limitations on auto-oriented uses, and potential reductions in required parking counts. Review the Concord Parking and Concord Development Standards pages for implementation details.

### Commercial Cannabis Overlay

• Purpose: The Commercial Cannabis Overlay is intended to permit careful geographic control of commercial cannabis businesses and to protect surrounding neighborhoods and uses (§ 18.110.010).
• Where it applies: The overlay is mapped and depicted in the ordinance figures; the overlay "overlays any underlying zoning district" and creates designated commercial cannabis overlay districts and a buffer zone shown in Figure 18.110.030(A) (§ 18.110.030).
• Typical permitted uses: The overlay permits specific cannabis land uses only as allowed by the underlying base district and only within the overlay: manufacturing, testing laboratories, microbusiness, non-storefront retail, distribution (Type 11 and Type 13) — subject to local licensing in Chapter 5.80 CMC and applicable state licenses (§ 18.110.030; § 18.110.050). Distribution transport-only (Type 13) is allowed only in conjunction with another permitted license type (§ 18.110.030).
• Key standards and controls:
  • Buffer: The overlay identifies a 600-foot buffer zone where no sensitive land uses or cannabis businesses shall be located, subject to limited exceptions (§ 18.110.030; § 18.110.040).
  • Development standards: The overlay defers to the underlying district’s development standards unless the overlay specifies otherwise (§ 18.110.060).
  • Licenses and permits: In addition to planning approvals, any cannabis operator must obtain a city cannabis license per Chapter 5.80 CMC and appropriate state licenses before operating (§ 18.110.050; § 18.110.070).
  • Conflict rule: Where a conflict exists between the commercial cannabis overlay and other provisions, the more restrictive regulation controls (§ 18.110.080).
• Practical note: Even where a cannabis use is allowed in the overlay, expect a multi-stage process (zoning/land-use permit + city cannabis license + state license) and careful distance/buffer checks against sensitive uses. See the land-use tables for district-specific permit types (e.g., AP, UP) to know whether a use requires an administrative permit or a use permit in the underlying district (see CDC use tables).

### Affordable Housing Overlay (AH)

• Purpose: The Affordable Housing Overlay (AH) provides an alternative, streamlined review pathway for housing development on sites identified in the city’s 2023–2031 Housing Element when at least 20 percent of units are affordable to lower-income households; it was adopted pursuant to California law (Government Code § 65583.2(c)) (§ 18.115.010). § 18.115.020 defines “by-right development” in the overlay.
• Where it applies: Applied to sites identified in the housing element and mapped in the overlay chapter (§ 18.115.030). Confirm a site’s AH mapping against the housing element sites inventory and the official zoning map.
• Typical permitted uses / effect on base zoning: The AH overlay enables "by-right development" for qualifying housing projects (i.e., projects that meet objective standards and provide required affordability) so that projects do not require conditional use or other discretionary permits that would make them a "project" under CEQA in many cases (§ 18.115.020; § 18.115.040). The overlay also identifies application and review authority, and how the overlay interacts with the state density bonus and other laws (§ 18.115.050–.070).
• Key standards:
  • Minimum affordability threshold: At least 20 percent of units affordable to lower-income households for the overlay’s by-right pathway (§ 18.115.010; § 18.115.040).
  • Relationship to density bonus and other state laws is expressly addressed; the overlay must be applied consistent with density bonus law and relevant state provisions (§ 18.115.070).
• Practical note: For AH-subject parcels, prepare to demonstrate objective compliance (design standards, parking, landscaping) and affordability commitments; review the overlay’s application requirements and the Concord Development Standards for applicable objective development standards.

Quick reference table — core overlays and top decision-relevant items

Checklist

• Verify whether the parcel is mapped with any overlay on the official zoning map and note which overlay(s) apply (verify with Planning). Verify map. § 18.10.030 (applies generally; use zoning map)
• For an A overlay parcel: determine if ALUC review is required and identify applicable airport-compatibility development standards ( § 18.100.030–.040 ) .
• For a TS overlay parcel: confirm proximity (one-half mile) to BART and review TS prohibited uses and pedestrian/ground‑floor standards ( § 18.105.020–.040 ); check parking reductions in CDC 18.160.050 .
• For a parcel in the Commercial Cannabis overlay: confirm that the desired cannabis land use is one the overlay allows and that local city cannabis license and state license requirements will be met. Check the 600‑foot buffer mapping ( § 18.110.030–.050 ) .
• For an AH parcel: confirm the site is listed in the housing element inventory and that the project will provide at least 20% lower-income units and meet the overlay’s objective standards (§ 18.115.010–.050) .
• Review the underlying base district’s allowed uses and development standards (setbacks, height, FAR, lot coverage). Cross-reference Concord Development Standards and applicable chapter tables to confirm whether the overlay changes those standards (CDC tables). Verify with the planning division. .
• Determine which discretionary or ministerial permits are still required (use permits, administrative permits, zoning clearances), and whether design review applies — consult Concord Design Review and Variances and Exceptions pages as needed. Verify with the planning division.

Risks & Ambiguities

Plain-English Summary

Concord’s overlay districts layer special rules on top of the base zoning: the Airport Overlay manages airport safety/compatibility, the Transit Station Overlay pushes for pedestrian, transit‑friendly development near BART, the Commercial Cannabis Overlay limits where and which cannabis activities can operate (with a 600‑ft buffer and local licensing), and the Affordable Housing Overlay creates a by‑right path for housing projects that provide at least 20% lower‑income units. Always check the map and both the overlay chapter and the underlying district tables; if anything is unclear, verify with the city’s planning division. § 18.100.010; § 18.105.010; § 18.110.010; § 18.115.010.

Source References

• Chapters and sections quoted in this reference page are from the Concord Development Code (Title 18): Chapter 18.100 Airport Overlay (A) — § 18.100.010–.040 .
• Chapter 18.105 Transit Station Overlay (TS) — § 18.105.010–.040 .
• Chapter 18.110 Commercial Cannabis Overlay District — § 18.110.010–.090 (including Figure 18.110.030(A) buffer mapping) . See use‑table excerpts for permit types and allowed cannabis uses in the code tables .
• Chapter 18.115 Affordable Housing Overlay District — § 18.115.010–.100 (purpose, requirements, application and relation to density bonus law) .
• General rules on zoning districts, development standards, and mapping appear in the Development Code’s district tables and introductory provisions (e.g., Table 18.15.020, CDC title and interpretation) § 18.10.010–.060; Table 18.15.020 .
• Parking reductions and rules close to BART stations referenced in the TS discussion: CDC 18.160.050 (parking, loading, and access) .

(If you need the ordinance pages themselves or the city’s official zoning map to confirm overlay boundaries for a parcel, request that and I’ll point you to the exact city pages or help prepare the questions to bring to planning staff.)

Retrieved passages

• CMC § 5.80.020 (§ 7) High relevance show source text
• CMC § 7 (§ 7) High relevance show source text
• Concord Zoning Code (§ 122-55) High relevance show source text
• Concord Zoning Code (Chapter 18.65) High relevance show source text
• CMC § 5.80.020 (Chapter 18.110) High relevance show source text
• Concord Zoning Code (§ 122-270) High relevance show source text
• Concord Zoning Code (article of) Medium relevance show source text
• Concord Zoning Code (Section 6409) Medium relevance show source text

Cited sections

• Chapters and sections quoted in this reference page are from the Concord Development Code (Title 18): **Chapter 18.100 Airport Overlay (A)** — **§ 18.100.010–.040** . (Title 18)
• **Chapter 18.105 Transit Station Overlay (TS)** — **§ 18.105.010–.040** . (Chapter 18.105)
• **Chapter 18.110 Commercial Cannabis Overlay District** — **§ 18.110.010–.090** (including Figure 18.110.030(A) buffer mapping) . See use‑table excerpts for permit types and allowed cannabis uses in the code tables . (Chapter 18.110)
• **Chapter 18.115 Affordable Housing Overlay District** — **§ 18.115.010–.100** (purpose, requirements, application and relation to density bonus law) . (Chapter 18.115)
• General rules on zoning districts, development standards, and mapping appear in the Development Code’s district tables and introductory provisions (e.g., Table 18.15.020, CDC title and interpretation) **§ 18.10.010–.060; Table 18.15.020** . (title and)
• Parking reductions and rules close to BART stations referenced in the TS discussion: CDC **18.160.050** (parking, loading, and access) .
• Concord_ZoningCode.md

• Official Concord code library