Humboldt County — Design Review

Overview

In unincorporated Humboldt County, “Design Review” is carried out through the D – Design Control combining zone and related coastal design standards. If your parcel is mapped with a D overlay, your project must undergo design review and secure a Special Permit before development proceeds (§ 19.1.2; § 19.1.3). The County also applies special scenic/view protections along the coast, local design review committees in places like Samoa (and procedures for Scotia), and countywide site-design rules (for example, outdoor lighting) that reviewers will enforce.

If your unincorporated parcel carries the D – Design Control overlay, any development requires a Special Permit and review against architectural, siting, materials, and scenic/view standards, in addition to underlying zoning (§ 19.1.2; § 19.1.3; § 19.1.3 [Architectural Standards]; § 19.1.5).

How to tell if you need Design Review

• Check whether your parcel in the unincorporated area is mapped with the D overlay (Design Control). Start from the county’s zoning maps and overlay districts.
• If in mapped coastal scenic or coastal view areas, coastal design findings also apply (§ 19.1.5.1.1–.1.2; § 19.1.7).
• Localized subareas like Shelter Cove, Samoa, and Scotia have additional D-specific standards, committees, or procedures (§ 19.1.5.1.3; § 19.1.4; § 19.1.9.3.2).

What Design Review Looks At

Design review in unincorporated areas with the D overlay evaluates:

• Architecture and site design: height/bulk/area, setbacks, exterior colors/materials, roof type/pitch/material, and signs (§ 19.1.3 [Architectural Standards] 19.1.3.1–.5).
• Consistency with the General Plan and, in mapped coastal scenic/view areas, visual subordination and view protection through height, width, and siting (including setbacks) (§ 19.1.5.1; § 19.1.5.1.1–.1.2; § 19.1.7).
• Special local standards, for example Shelter Cove height/side-yard adjustments to create view corridors (§ 19.1.5.1.3).
• Materials and form details (e.g., minimum residence width, roof overhangs, foundation approach in certain D areas) (§ 19.1.8.1.1–.1.4).

The reviewing authority may be a Board-appointed Design Review Committee (up to five members) or the Planning Director if no committee is in place (§ 19.1.4). For Samoa, a standing committee is created by ordinance (§ 19.1.4.1).

Process and timelines

• A Special Permit is required for all development subject to D regulations, with fees set by Board resolution (§ 19.1.3).
• For discretionary permits, any Design Review Committee must provide written comments within 10 working days of a complete application; these comments inform the hearing decision (§ 7.5.1.2.2; § 7.5.1.2.1; § 7.5.1.3–.1.5).
• Public hearings may be continued to allow written responses; staff can request agency attendance (§ 7.5.1.3–.1.4).

District-by-District (Design Review and Closely Related Overlays)

D – Design Control Combining Zone (Design Review)

• Purpose and where it applies: The D overlay is combined with any principal zone to preserve/enhance areas of historical, scenic, civic, cultural, architectural, or recreational value in unincorporated areas (§ 19.1; § 19.1 D – Design Control). It applies only on parcels mapped “D” (§ 19.1.2).
• Typical permitted uses: Those of the underlying principal zone; the D overlay adds design controls. Not found in source materials.
• Key standards:
  • Special Permit required; Board/Director-appointed reviewing authority; Samoa committee established (§ 19.1.3; § 19.1.4; § 19.1.4.1).
  • Architectural review covers height/bulk/area, setbacks, exterior colors/materials, roof type/pitch/material, and sign type/size/location (§ 19.1.3 [Architectural Standards] 19.1.3.1–.5).
  • General Plan and coastal scenic/view consistency criteria (§ 19.1.5.1–.1.2; § 19.1.7).
  • Material/form standards in certain D areas (e.g., minimum 20 ft residence width; 12 in roof overhang; restrictions on unfinished/galvanized metal exteriors) (§ 19.1.8.1.1; § 19.1.8.1.3–.1.4).

Shelter Cove Coastal View Areas (within D)

• Purpose and where it applies: Protect coastal public views and create side-yard view corridors in the Shelter Cove portion of the South Coast Area Plan (§ 19.1.5.1.3).
• Typical permitted uses: Underlying zone uses; D overlay modifies development form. Not found in source materials.
• Key dimensional standards:
  • Building height may increase by 1 ft for every 2 ft of extra side yard provided beyond the required 5 ft side yards, up to a max of 24 ft (§ 19.1.5.1.3).
  • Alternatively, one side yard may be reduced to 0 ft if the opposite side yard is 10 ft and the adjacent owner along the reduced side agrees to a similar reduction (§ 19.1.5.1.3.1; § 19.1.8.1.1.1).
  • Structure siting and setbacks must retain coastal views from public roads, trails, beaches, and recreation areas (§ 19.1.5.1.2).

Samoa Design Review Area (within D)

• Purpose and where it applies: Protect historic/cultural resources in the Samoa townsite; a dedicated committee conducts review in unincorporated areas mapped D (§ 19.1.4.1).
• Typical permitted uses: Underlying zone; D overlay adds historic/design controls. Not found in source materials.
• Key standards and process:
  • The Samoa Design Review Committee (five members) reviews alterations and new development for consistency with preservation standards (§ 19.1.4.1; § 19.1.9.1.3).
  • Alterations/demolitions of contributing structures are restricted; conditions can include documentation, delay, scale limits, and facade retention to protect district integrity (§ 19.1.9.1–.1.2.4).
  • Reviews reference the Secretary of the Interior’s Standards and Samoa Design Guidelines for designated properties (§ 19.1.9.1.3).

Scotia Historic–Design Review Procedure (within D)

• Purpose and where it applies: When no Scotia committee is appointed, applications in unincorporated Scotia D areas trigger a historic assessment process (§ 19.1.9.3.2).
• Typical permitted uses: Underlying zone; D overlay adds historic/design controls. Not found in source materials.
• Key standards and process:
  • Require a Historic Assessment Study—research plus field inventory by a qualified consultant, with mapped results and recommendations (§ 19.1.9.3.2.1–.2.2.4).
  • The study’s recommendations substitute for Design Review Committee recommendations in permit decisions and CEQA compliance (§ 19.1.4.1.2.4).

AP – Airport Safety Review Combining Zone (frequent co-overlay with D)

• Purpose and where it applies: Adds building/height limits for aviation safety on lands mapped AP in unincorporated areas (§ 16.3.2.1–.2).
• Typical permitted uses: Specified by an Airport Safety Review Zoning Matrix. Not found in source materials (§ 16.3.3).
• Key dimensional standards:
  • No structure/tree/object may exceed the airport height limits in County code § 331 (§ 16.3.4.1).
  • Buildings over 35 ft may be allowed only with a Special Permit (§ 16.3.4.2).

Countywide Outdoor Lighting Standards (applied in design review)

• Applicability: All zones in unincorporated areas must meet Outdoor Lighting standards; design reviewers may condition projects to ensure compliance (§ 105.1.2–.1.6).
• Key standards:
  • Shielding and downward direction; limit to active/safety use areas; no trespass to neighbors/biological resources (§ 105.1.2.1–.2).
  • Residential fixtures: max 1,100 lumens (§ 105.1.5.1).
  • Agricultural/commercial/industrial: max 3,200 lumens; boundary not over 0.3 foot-candles next to residential; along public ROW not over 1 foot-candle; pole-mount height max 20 ft; parking lots ≤ 2700 K CCT at night (§ 105.1.6.1–.1.3; § 105.1.6.2; § 105.1.6.3).
  • Prohibited systems include aerial lasers, searchlights, mercury vapor, flashing lights, and low-pressure sodium (§ 105.1.3.1).

Decision-Related Standards Table

Practical cross-checks reviewers use

• Base development standards like height measurement, accessory building heights, and special lot coverage exceptions may shape the “bulk” reviewers see:
  • Height measured from average ground to highest roof point; certain appurtenances excluded (§ 102.1.1).
  • Detached accessory buildings: max 15 ft height (≤20,000 sf lots) or 26 ft (>20,000 sf), with floor area caps; larger needs a Special Permit (§ 102.1.2.1–.2.2).
  • In mapped HOZ areas, single-story R-1 homes on lots ≤ 10,000 sf may cover up to 50% lot area (§ 99.1.4.2). Verify with the jurisdiction.

For related site controls like setbacks, parking, and landscaping that design reviewers may condition, see Humboldt County Development Standards, Parking, and Landscaping and Screening. For sign proposals within D areas, reviewers consider type/size/location; see Signage. Historic properties frequently involve Historic Preservation. If standards cannot be met, consult Variances and Exceptions.

Checklist

• Confirm the parcel is in unincorporated Humboldt County and mapped with the D overlay; note any overlapping overlays (e.g., AP) and mapped coastal scenic/view areas (§ 19.1.2; § 16.3.2; § 19.1.5.1.1–.1.2).
• Identify whether you are in a special D subarea: Shelter Cove, Samoa, or Scotia (§ 19.1.5.1.3; § 19.1.4.1; § 19.1.9.3.2).
• Prepare a Design Review submittal addressing architecture (height/bulk, setbacks, exterior materials/colors, roof, signs) and coastal view protections where applicable (§ 19.1.3 [Architectural Standards]; § 19.1.5.1.1–.1.2).
• If in Samoa or Scotia, include required historic assessments/guideline compliance; for Scotia, retain a Historic Assessment Study by a qualified professional (§ 19.1.9.1.3; § 19.1.9.3.2.1–.2.2.4).
• Demonstrate compliance with countywide outdoor lighting standards (fixture shielding, lumen limits, foot-candle limits, CCT) (§ 105.1.2–.1.6).
• If near airports (AP overlay), show compliance with height limits; obtain a Special Permit if proposing over 35 ft (§ 16.3.4.1–.4.2).
• File for the required Special Permit and pay fees; expect written design-review comments within about 10 working days of complete submittal (§ 19.1.3; § 7.5.1.2.2).
• Be prepared for public hearing conditions and potential agency attendance; address any required modifications before final approval (§ 7.5.1.3–.1.5).

Risks & Ambiguities

Plain-English Summary

If your unincorporated Humboldt County property has the D – Design Control overlay, you must get a Special Permit and pass design review. Reviewers look at your building’s size, setbacks, roof and exterior, signs, and how you protect public coastal views where mapped. In Shelter Cove, you may go up to 24 feet tall by widening side yards, or reduce one side yard to zero with conditions. Samoa and Scotia rely on historic-focused reviews. All projects must also meet countywide outdoor lighting limits.

Source References

• § 19.1 D – Design Control: purpose, applicability, and architectural standards; Special Permit requirement; Design Review Committee; Samoa committee; coastal scenic/view standards; Shelter Cove standards; alteration/demolition standards; Scotia procedure (§ 19.1; § 19.1.2; § 19.1.3; § 19.1.3 [Architectural Standards]; § 19.1.4; § 19.1.4.1; § 19.1.5; § 19.1.7; § 19.1.5.1.3; § 19.1.9.1; § 19.1.9.3.2; § 19.1.4.1.2.4; § 19.1.8.1)
• § 7.5.1.2–.1.5 Project review timelines and hearing procedures
• § 105.1 Outdoor Lighting standards (shielding, lumens, foot-candles, poles, prohibited systems)
• § 16.3.2–.3–.4 AP – Airport Safety Review combining zone (applicability; height standards; SP over 35 ft)
• § 102.1.1–.1.3 Height measurement and accessory building height/GFA limits
• § 99.1.4.2 R-1 HOZ lot coverage exception
• § 31.1.6 Design Guidelines for Planned Unit Developments; § 31.1.5.1 et seq. (context for PUD design considerations)

Source passages

• Humboldt County Zoning Code (§ 31.1.5.1) Medium relevance show source text
• Humboldt County Zoning Code (§ 31.1.5.1) Medium relevance show source text
• Humboldt County Zoning Code (§ 19.1) Medium relevance show source text
• Humboldt County Zoning Code (§ 99.1.4.2) Medium relevance show source text
• Humboldt County Zoning Code (§ 19.1.3) Medium relevance show source text
• CBC § 2784 (§ 19.1.8.1) Medium relevance show source text
• Humboldt County Zoning Code (§ 16.3.2) Medium relevance show source text
• Humboldt County Zoning Code (§ 19.1) Medium relevance show source text
• Humboldt County Zoning Code (§ 7.5.1.2) Medium relevance show source text
• Humboldt County Zoning Code (§ 19.1.7) Medium relevance show source text

Cited sections

• § 19.1 D – Design Control: purpose, applicability, and architectural standards; Special Permit requirement; Design Review Committee; Samoa committee; coastal scenic/view standards; Shelter Cove standards; alteration/demolition standards; Scotia procedure (§ 19.1; § 19.1.2; § 19.1.3; § 19.1.3 [Architectural Standards]; § 19.1.4; § 19.1.4.1; § 19.1.5; § 19.1.7; § 19.1.5.1.3; § 19.1.9.1; § 19.1.9.3.2; § 19.1.4.1.2.4; § 19.1.8.1) (§ 19.1)
• § 7.5.1.2–.1.5 Project review timelines and hearing procedures (§ 7.5.1.2)
• § 105.1 Outdoor Lighting standards (shielding, lumens, foot-candles, poles, prohibited systems) (§ 105.1)
• § 16.3.2–.3–.4 AP – Airport Safety Review combining zone (applicability; height standards; SP over 35 ft) (§ 16.3.2)
• § 102.1.1–.1.3 Height measurement and accessory building height/GFA limits (§ 102.1.1)
• § 99.1.4.2 R-1 HOZ lot coverage exception (§ 99.1.4.2)
• § 31.1.6 Design Guidelines for Planned Unit Developments; § 31.1.5.1 et seq. (context for PUD design considerations) (§ 31.1.6)