Commercial Real Estate in Angwin: Neighborhood Commercial, Winery Rules and the Angwin Airport

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

Angwin is an unincorporated community on Howell Mountain, above the Napa Valley floor and home to Pacific Union College. Commercial property here means a small neighborhood commercial core, service and trade businesses, and wineries and vineyards on the surrounding agricultural land. Napa County writes several rules specifically for Angwin, and its winery and agricultural land rules shape most deals on the surrounding land. Confirm the zoning, any airport zone and the use permit history for each parcel with Napa County Planning, Building and Environmental Services.

Who controls the parcel

Angwin has no city government, so Title 18 of the Napa County Code governs all land use. Three layers shape what a parcel can do:

• General Plan map and the voter-approval rule. The County’s August 20, 2008 Planning Commission staff letter explains that Measure J, adopted by voters in 1990, requires a public vote to redesignate land shown as Agricultural Resource or Agriculture, Watershed and Open Space on the land use map, with narrow exceptions. Expanding or moving the urban and rural residential "bubbles" also needs a vote. The County’s Agricultural Preservation and Land Use Element confirms that voters adopted Measure P in 2008, so the Measure J/P policies cannot be changed without a public vote until after December 31, 2058; the 2008 letter also describes a narrow affordable housing exception. In practice, turning Angwin farmland into commercial land is close to impossible without an election.
• Zoning districts. The base district (CN, AP, AW, residential or planned development) sets the uses.
• Airport overlay. Land near the Angwin Airport is in the AC combining district, which controls where it conflicts with the base zone.

Confirm who provides water and sewer to the parcel, and their capacity, before planning any expansion; the County’s own housing chapter expects a will-serve letter for new units.

Angwin zoning for commercial and agricultural business

Minimum lot sizes come from the schedule in Section 18.104.010.

The CN district’s Angwin-only uses

The CN chapter’s purpose statement singles out Angwin, along with Lake Berryessa and Capell Valley, as isolated areas where somewhat broader commercial uses fit. Nothing in CN is allowed by right except agriculture and minor antennas.

Countywide CN uses (use permit):

• small retail shops of up to 2,500 square feet each, including bakeries, hardware and liquor stores
• food markets under 28,000 square feet
• personal services
• medical and general offices
• small branch banks without drive-throughs
• child care
• gas stations with incidental repair

Angwin additions (use permit):

• auto supply, repair, service and detailing shops
• awning, upholstery, framing and cabinet shops under 2,500 square feet
• service businesses such as plumbing, cleaning and landscaping
• contractor offices with incidental outdoor storage

Not on the list. Restaurants and cafes appear only in the Lake Berryessa and Capell Valley list, not Angwin’s. Lodging is not mentioned in CN. Confirm the permit path with the County before planning food service or rooms.

Standards. Parking is one space per 500 square feet plus one per employee, and none may sit in setbacks. Other standards:

• 6-foot fencing or hedges plus a 10-foot landscaped strip at residential edges
• repair and detailing work fully enclosed
• outdoor storage screened, up to 15 feet
• buildings set 50 feet back from stream banks

A commercial ADU is possible with a use permit if it is deed-restricted to moderate-income or lower households.

Wineries and agricultural processing

Most Angwin commercial value outside the CN core is in wineries, and the County’s winery rules in Chapter 18.104 date largely from Ordinance 947 in 1990:

• Parcel size. A new winery on AP or AW land needs at least 10 acres. Pre-Prohibition wineries may qualify on 2 acres, capped at 20,000 gallons a year.
• Grape source. New wineries must source at least 75% of their still-wine grapes from Napa County, and so must the added production of an expansion.
• Road setbacks. Wineries must sit 600 feet from the centerline of a state highway, Silverado Trail or arterial county road, and 300 feet from other public roads. Underground cave space is exempt, but visible portals are not.
• Coverage. In open space areas, a new or expanded winery may cover no more than 25% of the parcel or 15 acres, whichever is less.
• Accessory space. Tasting, marketing and other accessory structures are capped at 40% of the production facility’s area.
• Small wineries. Wineries set up after July 31, 1974 without a use permit are capped at their exemption limit or 20,000 gallons, whichever is less. Growth needs a use permit.

In AP, wineries, tours and tastings, and on-site retail all need a use permit and must stay subordinate to production. An agricultural processing facility of up to 5,000 square feet may be allowed on a parcel of ten acres or more if it sells only products raised or processed there. Buyers should read each winery’s use permit for production, visitor and event limits.

Angwin Airport and other site rules

• Airport zones. Under Section 18.80.030, revised by Ordinance 1511 on August 19, 2025, the Angwin Airport–Parrett Field has six compatibility zones. The zones follow the Countywide Airport Land Use Compatibility Plan adopted December 4, 2024. Plan amendments, rezonings and conditionally compatible uses go to the Airport Land Use Commission, and the Board can override its finding only by a two-thirds vote.
• Short stays. Section 18.104.410 bars transient commercial occupancy of dwellings in every residential and agricultural district, so homes and cottages cannot be run as vacation rentals.
• Home wine production. Home occupations may make or store wine for sale only under 200 gallons a year, with no on-site sales.

Transfer tax, business tax and property tax

Napa County’s document transfer tax page gives a rate of $0.55 per $500 of value, notes that assumed loans may be excluded, and says the seller customarily pays in Northern California. There is no city tax in unincorporated Angwin. Ask the County’s Treasurer-Tax Collector about any business license or lodging tax. A sale generally triggers Proposition 13 reassessment, and land under a Williamson Act contract is assessed differently, so check for one.

Due diligence that matters in Angwin

Start with our commercial due diligence checklist, then add:

• Confirm the zoning and General Plan designation, and whether any change would need a public vote.
• Pull every use permit. In CN, nearly every use depends on one.
• For a winery, check production limits, visitor and event caps, grape sourcing and road setbacks.
• Identify the Angwin Airport compatibility zone and any ALUC conditions.
• Get will-serve letters or capacity confirmation from the water and sewer providers.
• Check for a Williamson Act contract and stream setbacks.

Questions people ask

Sources & notes

1. Napa County Code Chapter 18.32, CN Commercial Neighborhood (GoCodebook)
2. Chapter 18.16, AP Agricultural Preserve
3. Chapter 18.104, including winery sections 18.104.200–.255 and the 18.104.010 schedule
4. Section 18.104.410, transient occupancy of dwellings
5. Chapter 18.80, AC Airport Compatibility
6. Napa County Planning Commission agenda letter, August 20, 2008 (Measures J and P)
7. Napa County General Plan, Agricultural Preservation and Land Use Element (Measure P adoption and 2058 term)
8. Napa County, Document Transfer Tax

Note: We did not review the ALUCP exhibits, the PD districts in Angwin, the marketing rules in 18.104.255, or the identity and capacity of Angwin’s water and sewer providers.

This page is general information, not legal or tax advice. Last reviewed October 2026 by Matthew Martinez.

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