Redlands — Overlay Districts

Last reviewed: July 2, 2026

Overview

Overlay districts in Redlands are superimposed zoning layers that sit on top of the city's base zoning map and add site- or area‑specific rules (restrictions, procedural triggers, or design criteria). The Redlands code lists three overlays — C-D (Civic Design), AF (Airport Flight Zone), and HD (Hillside Development) — and ties their boundaries to the official zoning map. See § 18.16.010 for the list of overlays.

The text below stays strictly to what Redlands's Title 18 says: it summarizes the stated purpose, where each overlay applies, the key permit or design triggers and the most decision‑relevant dimensional / process rules that applicants must expect to satisfy. Where the ordinance text for an overlay is not present in the retrieved materials, that gap is called out and you are told to verify with the City.

Before you proceed with a project, check the city's development standards, the design review rules, and the parking requirements because overlays often add procedural steps that interact with those rules.

Overlay districts (district‑by‑district)

C-D (Civic Design District)

• Purpose: The C-D overlay exists “to promote the orderly, harmonious development” of areas adjacent to civic facilities (civic center, parks, areas of public interest) and to ensure high appearance standards in those areas. See § 18.80.010.
• How it applies: The C-D district is a superimposed zone that is combined with an underlying base zone on the zoning map (e.g., C-3, C-D). The overlay’s rules are in addition to the underlying zone, and when they conflict the C-D provisions control. See § 18.80.020.
• Typical permitted uses: Principal, accessory and conditional uses are the same as the underlying zone unless the C-D chapter says otherwise (so check the base zone’s use list first). See § 18.80.030.
• Key triggers and standards:
  • Development plan approval by the Planning Commission is required for new non‑residential structures, moving a structure, substantial exterior alterations, alteration of signs/walls/fences, major outdoor lighting changes, and whenever an outdoor use is established/enlarged/changed. See § 18.80.040.
  • In reviewing plans the Commission evaluates exterior appearance (height, bulk, materials), color/texture, relation to neighboring buildings, setbacks and landscaping, and similar design criteria. See § 18.80.050.
• Practical guidance: Expect the Commission to require design elevations, landscaping plans and conditions that go beyond the underlying zone’s numerical standards. Link early with the city's design review process and be prepared for conditional project conditions that affect signage and lighting (see signage). See § 18.80.050.

HD (Hillside Development District)

• Purpose: The HD overlay protects public health and safety in hillside areas, preserves ridgelines and scenic vistas, and implements General Plan hillside policies. See § 18.138.010.
• Where it applies: The HD overlay applies to any parcel with an average cross slope of 15% or greater, and to parcels containing any portions with slopes of 15% or greater (the code references the City's slope identification map and the Live Oak Canyon area). See § 18.138.030.
• Objectives (high level): minimize erosion/runoff, retain natural topography and skylines, avoid conspicuous development on hilltops, provide safe circulation, reduce wildland fire exposure, and protect groundwater. See § 18.138.020.
• Typical permitted uses: Uses must conform to the HD chapter’s requirements; residential and subdivision activity in hillside areas is explicitly regulated via slope‑based density and building envelope rules (see Development Plan requirements). See § 18.138.060–.070.
• Key dimensional / submittal standards:
  • Average cross‑slope calculation method and mapping requirements are specified (topographic maps with contour intervals, soils map, certified slope analyses). See § 18.138.070.
  • Final maps for projects subject to HD must indicate a surveyable building envelope for each affected lot consistent with the approved slope plan. See § 18.138.070(G).
  • Grading and cut/fill limitations, erosion control, slope landforming, and special slope ratios are required; for example, the broader grading chapter permits less aggressive slope ratios elsewhere, and in some HD contexts the Planning Commission may allow a 2:1 slope where otherwise 3:1 is standard — see § 18.144.280 and HD development standards.
• Practical guidance: If your parcel is near the 15% threshold, commission review will hinge on technical slope reports and precisely drawn building envelopes — hire a civil/topographic engineer early and expect required mitigation measures (erosion control, landscaping). See § 18.138.030 and § 18.138.070.

AF (Airport Flight Zone)

• What the code contains: The AF overlay is explicitly listed as one of the three overlay districts in § 18.16.010, but detailed AF chapter text or operational standards were not contained in the retrieved materials. See § 18.16.010.
• Practical note: Because the code excerpt provided here does not include AF’s detailed provisions, you must verify AF boundaries and any height, lighting, or use restrictions with the City (planning department) and the official zoning map. Not found in retrieved materials. Verify with the jurisdiction.

Quick reference table — decision‑relevant items

Checklist

• Confirm whether your parcel is inside C‑D, HD, or AF on the official zoning map (the overlay layer is part of the zone map). See § 18.16.020.
• If in C‑D, prepare elevations, landscaping, lighting and sign details for Planning Commission development plan review (trigger per § 18.80.040).
• If in HD, secure a certified slope/topographic analysis, soils map and proposed building envelope as required by § 18.138.070.
• Coordinate with the City on parking and development standards that still apply from the underlying zone. See § 18.80.020 for C‑D conflict rule.
• If your project involves exterior alterations, expect to meet design review submittal standards and potentially additional conditions tied to signage and lighting. See § 18.80.050.
• For building work, ensure compliance with the California Building Standards Code; overlays do not replace building code requirements. Not an overlay provision — building code reference.
• If AF is implicated, verify any airport/flight‑path restrictions with the City and responsible airfield agency — AF specifics were not located in the retrieved code. Not found in retrieved materials.

Risks & Ambiguities

Plain‑English Summary

Redlands has three overlay zones: C‑D (design control around civic areas), HD (special rules where slopes are 15%+), and AF (airport flight zone listed on the map). C‑D adds design review and Commission development‑plan requirements; HD requires slope maps, site‑specific building envelopes and erosion/ grading controls; AF is listed but detailed AF rules were not present in the retrieved ordinance text — verify with the City. See § 18.16.010, § 18.80.010–.050, and § 18.138.010–.070.

Source References

• RMC § 18.16.010 (Division of City into districts; overlays listed: C‑D, AF, HD)
• RMC § 18.80.010, § 18.80.020, § 18.80.030, § 18.80.040, § 18.80.050 (Civic Design District — purpose, superimposed nature, permitted uses, development plan triggers, design criteria)
• RMC § 18.138.010, § 18.138.020, § 18.138.030, § 18.138.040, § 18.138.050, § 18.138.060, § 18.138.070 (Hillside Development District — purpose, objectives, slope threshold, map/submittal and development plan requirements)
• RMC § 18.144.280 (grading restrictions and slope ratio allowance referenced for HD contexts)
• RMC § 18.12.140–.160 (Architectural/Design Review triggers and procedure) — see chapter headings for design review procedures and scope.

Also referenced (internal guidance links you should consult early in project planning): Redlands Zoning, Redlands Development Standards, Redlands Parking, Redlands Design Review, Redlands Signage, Redlands Historic Preservation, Redlands ADUs, and California Building Standards Code.

Retrieved passages

• CBC § 18.156.1220 (Article conflicts) High relevance show source text
• Redlands Zoning Code (§ 22.52) High relevance show source text
• Redlands Zoning Code (§ 22.52) Medium relevance show source text
• Redlands Zoning Code (section 65913.3) Medium relevance show source text
• CWUIC § 164 (Article I) Medium relevance show source text
• Redlands Zoning Code (§ 1) Medium relevance show source text
• Redlands Zoning Code (Chapter 18.12) Medium relevance show source text
• Redlands Zoning Code (title individually) Medium relevance show source text
• Redlands Zoning Code (§ 31.65) High relevance show source text
• Redlands Zoning Code (§ 1) High relevance show source text
• Redlands Zoning Code (section 18.136.050) High relevance show source text
• Redlands Zoning Code (§ 22.61) Medium relevance show source text
• Redlands Zoning Code (section 18.12.110) Medium relevance show source text
• Redlands Zoning Code (section 18.168.220) Medium relevance show source text
• Redlands Zoning Code (§ 5) Medium relevance show source text

Cited sections

• RMC **§ 18.16.010** (Division of City into districts; overlays listed: **C‑D**, **AF**, **HD**) (§ 18.16.010)
• RMC **§ 18.80.010**, **§ 18.80.020**, **§ 18.80.030**, **§ 18.80.040**, **§ 18.80.050** (Civic Design District — purpose, superimposed nature, permitted uses, development plan triggers, design criteria) (§ 18.80.010)
• RMC **§ 18.138.010**, **§ 18.138.020**, **§ 18.138.030**, **§ 18.138.040**, **§ 18.138.050**, **§ 18.138.060**, **§ 18.138.070** (Hillside Development District — purpose, objectives, slope threshold, map/submittal and development plan requirements) (§ 18.138.010)
• RMC **§ 18.144.280** (grading restrictions and slope ratio allowance referenced for HD contexts) (§ 18.144.280)
• RMC **§ 18.12.140–.160** (Architectural/Design Review triggers and procedure) — see chapter headings for design review procedures and scope. (§ 18.12.140)
• Redlands_ZoningCode.md

• Official Redlands code library