Napa County — Historic Preservation

Last reviewed: July 6, 2026

Overview

In unincorporated Napa County, the zoning ordinance (Title 18) weaves historic preservation into a few targeted provisions rather than a standalone historic zoning program. These provisions principally address reuse of designated landmarks, exceptions for historic winery sites, and exclusions for ministerial two‑unit development on historic properties. This page synthesizes what Title 18 says—and does not say—about historic preservation for the unincorporated areas; incorporated cities within Napa County run separate codes and programs.

The zoning code’s most powerful preservation tools in unincorporated areas are: (1) special findings and procedures to reuse designated “Landmarks of Special Significance,” and (2) narrowly drawn exceptions that let historic winery sites deviate from standard setbacks and minimum parcel sizes when projects follow the Secretary of the Interior’s Standards.

How historic resources show up in Napa County Zoning (Title 18)

• The stated purposes of zoning include preserving “sites and structures of a special historical, archaeological or architectural character” in the unincorporated areas (§ 18.01 purpose statement) .
• Reuse of County‑designated “Landmarks of Special Significance” (designated under County Code Chapter 15.52) is allowed if you obtain a use permit and make additional landmark‑specific findings; the code cross‑references both the general use permit findings and these special preservation findings (§ 18.132.065; § 18.124.070; § 18.104.430) .
• Historic winery sites can qualify for reduced winery setbacks from major roads when a project preserves and incorporates historic buildings/landscapes and conforms to the Secretary’s Standards (§ 18.104.235) .
• “Pre‑Prohibition” wineries—substantially intact buildings used as wineries before Prohibition—may be reactivated under modified rules, including a lower minimum parcel size and exceptions to standard setbacks, subject to a use permit and preservation findings (§ 18.104.245) .
• Ministerial two‑unit developments (SB 9) are categorically ineligible on parcels that are designated local landmarks, listed on the State Historic Resources Inventory, or within historic districts designated by ordinance (§ 18.104.440) .

For general context on zones and how these provisions interact with base districts, see the County’s summaries of Napa County Zoning, Napa County Land Use, and Napa County Development Standards.

Districts and Overlays That Matter for Historic Preservation

:HR Historic Restaurant Combination District

• Purpose: Chapter 18.103 establishes the :HR Historic Restaurant Combination District (§ 18.103.010) .
• Typical permitted uses: Not found in retrieved materials.
• Key dimensional standards: Not found in retrieved materials.
• Where it applies: Not found in retrieved materials.
• Practical note: The chapter’s existence signals a tailored tool for historic restaurant sites. However, because the retrieved text does not include operative provisions, applicants should Verify with the jurisdiction for the location list, allowed uses, and standards.

AP and AW (Winery Historic Exceptions)

• Purpose: In the AP (Agricultural Preserve) and AW (Agriculture, Watershed & Open Space) base districts, wineries are regulated with minimum parcel sizes and road setbacks; historic exceptions may apply.
• Typical winery thresholds: Minimum parcel sizes for wineries are one acre for certain pre‑1990 establishments and ten acres for wineries established after code adoption (§ 18.104.240) .
• Historic exceptions that may modify standards:
  • Setbacks near major roads may be reduced to no less than 300 ft when a qualified historic resource will be preserved and integrated, and the project conforms to the Secretary’s Standards (§ 18.104.235) .
  • “Pre‑Prohibition wineries” (substantially intact—four walls and a roof) can be reused with a two‑acre minimum parcel size and without standard winery setback requirements if the same preservation findings from § 18.104.235 are met (§ 18.104.245) .
• Where it applies: Unincorporated parcels zoned AP or AW proposing wineries or accessory winery uses, especially where historic buildings/landscapes exist (§§ 18.104.235–.245) .

Countywide SB 9 Two‑Unit Developments (Historic Area Exclusion)

• Purpose: Implement state two‑unit law ministerially, while excluding historic resources from ministerial approval.
• Key rule: A two‑unit development cannot be approved ministerially if the parcel is within a historic district or listed/designated as a historic resource or Napa County landmark (§ 18.104.440) .
• Where it applies: Countywide in unincorporated areas proposing ministerial two‑unit projects; see Napa County Design Review for how objective standards may also apply.

Key standards and approval pathways

• Use permits for landmark reuse require the standard use permit findings plus six preservation‑specific findings, including long‑term preservation, public understanding, compatibility with agriculture, no urbanization, adequate utilities/parking, and maintenance per a plan prepared by a Qualified Preservation Professional (§ 18.124.070; § 18.104.430) .
• Use permits may carry conditions on access, parking, environmental mitigation, landscaping and screening, signage, and lighting (§ 18.124.060) .
• Winery historic setback exception requires findings that: the site contains listed/eligible historic resources; the project stays within an existing developed footprint and scale; a sitewide preservation plan is in place with certification of conformance to the Secretary’s Standards; and the new structure is not closer to roads than existing historic structures (§ 18.104.235) .
• Pre‑Prohibition winery reuse hinges on a “substantially intact” structure (four walls and a roof) and is paired with the same preservation findings used for historic setbacks; the minimum parcel size is two acres (§ 18.104.245) .

Table — Decision-relevant historic preservation standards (unincorporated areas)

Process notes and practical guidance

• Start with designation: many rules trigger only if a site is a County landmark or otherwise recognized as historic. Title 18 cross‑references designations maintained under County Code Chapter 15.52 (Landmarks of Special Significance) (§ 18.132.065) . Not found in retrieved materials: the Chapter 15.52 designation procedures and list.
• For landmark reuse, build your case around the Secretary’s Standards and a clear, funded maintenance plan prepared by a Qualified Preservation Professional; be ready for annual inspections as a permit condition (§ 18.104.430) .
• For wineries on historic sites, map all road setbacks and show the project’s location within the existing developed footprint. The exception cannot place new structures closer to roads than existing historic buildings (§ 18.104.235) .
• Ministerial two‑unit projects cannot override local historic protections—the historic exclusion is categorical (§ 18.104.440) .
• Expect use permit conditions covering circulation, parking, landscaping and screening, and signage (§ 18.124.060) . If design standards apply, coordinate early with Napa County Design Review.
• Building work is governed separately under the California Building Standards Code. This page does not cover construction code alternatives such as the California Historical Building Code.

Checklist

• Confirm if the parcel is a County landmark or in a designated historic district (Title 15.52; Verify with the jurisdiction) and/or listed/eligible on state/national registers (§ 18.132.065; § 18.104.235) .
• If reusing a Landmark of Special Significance, prepare a use permit application addressing both the general findings and the six preservation findings (§ 18.124.070; § 18.104.430) .
• For winery projects on historic sites, document listing/eligibility, prepare a sitewide preservation plan, and certify conformance with the Secretary’s Standards (§ 18.104.235) .
• For pre‑Prohibition winery reuse, verify the building is “substantially intact,” confirm the parcel is at least two acres, and apply for a use permit with the required historic findings (§ 18.104.245) .
• If pursuing a ministerial two‑unit project, verify that the property is not a designated/listed historic resource or in a historic district (§ 18.104.440) .
• Anticipate and plan for conditions on access, parking, signage, lighting, and landscaping (§ 18.124.060) .
• Coordinate early with Napa County Zoning staff on applicability of Napa County Overlay Districts and any needed Napa County Variances and Exceptions if site constraints arise.

Risks & Ambiguities

Information Gaps

• Full text of Chapter 18.103 (:HR Historic Restaurant Combination District) — Not found in retrieved materials.
• The designation procedures and current list of County “Landmarks of Special Significance” in Chapter 15.52 — Not found in retrieved materials.
• Any additional historic overlay districts or mapped boundaries beyond what’s referenced by cross‑citation — Not found in retrieved materials.

Plain-English Summary

If your project in unincorporated Napa County involves a historic building or a County‑designated landmark, zoning can both help and constrain you. Expect to go through a use permit with extra preservation findings, and if you’re reviving a historic winery site, the code may relax some setbacks and parcel size rules—provided you preserve the resource and follow the Secretary’s Standards.

Source References

• § 18.01 purpose statement (historic preservation purpose) — Napa County Zoning Code
• § 18.104.235 winery setback exception for historic resources — Napa County Zoning Code
• § 18.104.240 winery minimum parcel size (AP/AW) — Napa County Zoning Code
• § 18.104.245 pre‑Prohibition winery exceptions — Napa County Zoning Code
• § 18.104.430 landmark reuse findings (as referenced) — Napa County Zoning Code
• § 18.104.440 two‑unit developments (historic exclusion) — Napa County Zoning Code
• § 18.124.060 use permit conditions — Napa County Zoning Code
• § 18.124.070 use permit findings — Napa County Zoning Code
• § 18.132.065 Landmarks of Special Significance—Use and continuance — Napa County Zoning Code
• Chapter 18.103 :HR Historic Restaurant Combination District (chapter heading) — Napa County Zoning Code
• For general context pages: Napa County zoning & planning overview, Napa County Overlay Districts

Retrieved passages

• Napa County Zoning Code (Section 18.104.230) High relevance show source text
• Napa County Zoning Code (Section 18.124.070) High relevance show source text
• CBC § 7060 (Chapter 12.75) Medium relevance show source text
• Napa County Zoning Code Medium relevance show source text
• Napa County Zoning Code (Chapter 18.100) Medium relevance show source text
• Napa County Zoning Code (section may) Medium relevance show source text
• Napa County Zoning Code (Section 18.136.040.) Medium relevance show source text
• CBC § 44 (chapter and) Medium relevance show source text

Cited sections

• § 18.01 purpose statement (historic preservation purpose) — Napa County Zoning Code (§ 18.01)
• § 18.104.235 winery setback exception for historic resources — Napa County Zoning Code (§ 18.104.235)
• § 18.104.240 winery minimum parcel size (AP/AW) — Napa County Zoning Code (§ 18.104.240)
• § 18.104.245 pre‑Prohibition winery exceptions — Napa County Zoning Code (§ 18.104.245)
• § 18.104.430 landmark reuse findings (as referenced) — Napa County Zoning Code (§ 18.104.430)
• § 18.104.440 two‑unit developments (historic exclusion) — Napa County Zoning Code (§ 18.104.440)
• § 18.124.060 use permit conditions — Napa County Zoning Code (§ 18.124.060)
• § 18.124.070 use permit findings — Napa County Zoning Code (§ 18.124.070)
• § 18.132.065 Landmarks of Special Significance—Use and continuance — Napa County Zoning Code (§ 18.132.065)
• Chapter 18.103 :HR Historic Restaurant Combination District (chapter heading) — Napa County Zoning Code (Chapter 18.103)
• For general context pages: Napa County zoning & planning overview, Napa County Overlay Districts
• NapaCounty_ZoningCode.md

• Official Napa County code library