Napa County Winery Use Permits: New, Micro and Modified Wineries
A Napa County winery use permit is the discretionary land-use approval, issued under County Code Chapter 18.124, that lets a parcel host wine production and set amounts of visitation, marketing and building area. New wineries and major changes go to the Planning Commission, and smaller tracks, such as micro-wineries and administrative modifications, can be decided by the Zoning Administrator or the planning director. Every track has to fit the Winery Definition Ordinance: a 10-acre minimum parcel for a new winery, at least 75% Napa County grapes, and accessory space no larger than 40% of the production area.
The county’s application packets, revised in March 2026, now set out seven categories, from a new winery to a very minor modification. This guide explains which track fits which project, what studies the county asks for, how the hearing process works, and how to read the permit attached to a winery you are thinking of buying. The rules themselves are covered in our guide to the Napa Winery Definition Ordinance; this page is about the process.
Permit tracks at a glance
The table summarizes the March 2026 packets from Napa County Planning, Building and Environmental Services (PBES). Confirm the right track at a pre-application meeting, which the county recommends.
| Track | Typical project | Who decides | Key limits |
|---|---|---|---|
| New winery use permit | A winery on a parcel without one | Planning Commission | 10-acre minimum parcel; 75% Napa grapes; 40% accessory; winery coverage up to 25% of the parcel or 15 acres, whichever is less |
| Major modification | More production, visitors, events or building area beyond the minor thresholds | Planning Commission | Must conform to current rules |
| Minor or very minor modification | Smaller changes to an existing permit | County staff or Zoning Administrator, by track | Thresholds set by the code and packet |
| Winery administrative permit | Limited changes listed in Section 18.126.065 | Director or Zoning Administrator | For example, building area changes of no more than 10% and 2,500 square feet |
| Micro-winery use permit | A very small estate winery | Zoning Administrator, after a noticed hearing | 5,000 gallons capacity; 5,000 square feet; 20 daily trips; no marketing events |
| Small winery (existing exemption) | A winery holding a certificate of exemption issued before February 22, 1990 | Per the packet’s procedure | 20,000 gallons a year; 10,000 square feet; 40 daily trips; up to 11 events a year |
Before you buy: is the parcel eligible?
Many buyers look at a vineyard parcel and assume a winery can follow. Check four things first:
- Parcel size. The 2015 Napa County Grand Jury report summarizes the WDO’s 10-acre minimum parcel for new wineries. Smaller existing wineries operate under older permits or certificates of exemption.
- Zoning. Confirm the parcel’s zoning district before anything else. The micro-winery track is limited to the Agricultural Preserve (AP) and Agricultural Watershed (AW) zones. See our guide to AP and AW zoning.
- Grapes. New wineries, and expansions after January 23, 1990, must source at least 75% of their grapes from Napa County. The application asks for an Initial Statement of Grape Source.
- Water, wastewater and access. These often decide whether a site works at all. Road access must meet the county’s Road and Street Standards or win an exception.
If the parcel fails one of these, a custom crush or alternating proprietor arrangement may be the practical route; see how to start a winery.
The micro-winery permit
The micro-winery track is for very small production on the grower’s own land. Under the March 2026 packet and County Code Section 18.08.377, a micro-winery:
- Ferments at least 201 gallons a year on site, with a capacity of no more than 5,000 gallons.
- Uses grapes at least 75% of which come from the permit property or contiguous parcels under the same ownership included in the application.
- Has no more than 5,000 square feet of enclosed space, including storage, processing, tasting areas and caves.
- Generates no more than 20 average daily trips from visitors, employees and deliveries.
- Holds no marketing events on site, and limits tours, tastings and retail sales to 9 a.m. to 6 p.m.
The Zoning Administrator decides after a noticed public hearing and may refer non-routine projects to the Planning Commission. Notice goes to owners within 1,000 feet at least 10 calendar days before the decision. No request to increase production or visitation is considered for two years after approval, and a micro-winery that receives a major modification no longer counts as one.
The small winery exemption
The small winery packet covers wineries “issued a certificate of exemption prior to February 22, 1990.” Its procedure recognizes existing entitlements or allows listed uses within these limits:
- Production of 20,000 gallons a year or less.
- No more than 40 average daily trips from visitors, employees and deliveries.
- No more than 10,000 square feet of occupied space, including caves; unenclosed space such as covered crush pads is excluded.
- Up to 11 marketing events a year, with total trips on event days capped at 40.
The packet doesn’t say whether new exemptions can be issued, and the Grand Jury noted that expanding beyond an exemption requires full WDO compliance. If you are buying a small exempt winery, the certificate and any later approvals are the documents that define its rights.
Modifying an existing permit
Most permit work on a winery you buy will be a modification. The track depends on the size of the change:
- Administrative permits under Section 18.126.065 cover limited changes. Examples in the packet include outdoor shade structures up to 2,500 square feet in total and building area changes of no more than 10%, capped at 2,500 square feet.
- Minor and very minor modifications cover changes below the major thresholds; confirm the current limits with PBES before you plan around them.
- Major modifications go to the Planning Commission and must meet today’s rules, including the 75% grape rule for added production.
For a pre-WDO winery, the grape source statement is required when it expands beyond its winery development area. So an older winery’s flexibility can shrink the moment it asks for more.
Existing violations now matter more for a modification. The Napa Valley Register and Vinetur reported that on March 10, 2026 the Board of Supervisors voted to end the county’s voluntary winery code compliance program, effective April 30, 2026. According to those reports, a winery has to comply with its current permit before the county will consider changes; confirm the policy with PBES.
What the application requires
The March 2026 winery packet lists the core submittals:
- Application form, authorization, hourly fee agreement, and certification and indemnification forms.
- A detailed project description, site and building plans, floor plans and elevations, and a title report.
- The Supplemental Application for Winery Uses and the Initial Statement of Grape Source.
- A marketing program describing event types, attendance, hours and overflow parking.
- A Water Availability Analysis or groundwater study; our guide to Napa groundwater rules explains the screening limits.
- A wastewater feasibility report for new, upgraded or expanded systems; see winery wastewater.
- A trip generation sheet. A full traffic impact study may not be needed for projects adding fewer than 110 daily trips.
- As applicable: biological, cultural and historic studies, a noise study if a sensitive receptor is within 500 feet, a water system feasibility report for 25 or more people, and a stormwater control plan.
Projects also face CEQA review, and some may qualify for a categorical exemption under the county’s local procedures. Vineyard work tied to the project, such as new plantings on slopes, has its own approvals; see vineyard development.
The process, step by step
- Pre-application meeting. PBES recommends one to confirm the track and the studies.
- Submit with a deposit. Fees are time-and-materials or flat under the county’s fee policy, and the applicant owes costs even if the project is withdrawn or denied.
- Completeness review. The county determines completeness within 30 days of submittal and payment, under the Permit Streamlining Act.
- Environmental review. Staff prepares the CEQA document or exemption.
- Hearing. The Planning Commission decides new wineries and major modifications; the Zoning Administrator decides micro-wineries and some smaller matters.
- Appeal. The Grand Jury report notes that a permit decision can be taken to the Board of Supervisors.
- Use it. Under Section 18.124.080, a use permit expires two years after approval unless its conditions set a different period, so plan financing and construction to fit.
On timing, the 2015 Grand Jury report said reviews “frequently require 9 to 12 months or more before a permit is issued,” at the applicant’s cost. We haven’t found a newer county figure, so treat that as a floor for a major project.
Reading a seller’s permit
When you buy a permitted winery, you buy its approvals and their conditions. Ask the seller and the county for:
- The original use permit or certificate of exemption, every modification and the conditions of approval for each.
- Approved annual production, daily and weekly visitors, marketing events and hours.
- Production and visitation records to compare with those limits, and any county audit results.
- WAA, wastewater and traffic conditions, such as monitoring or reporting.
The 2015 Grand Jury reported that the county audited about 20 wineries a year, so ask whether this one has been audited and get any results in writing. Our winery due diligence checklist puts the permit review alongside licensing and equipment, and our winery valuation guide explains how permitted capacity affects price. For the Sonoma side of the county line, see Sonoma County winery use permits.
This is general information, not legal advice; before relying on a permit’s terms, check them with a California land-use attorney and Napa County planning staff.
Questions people ask
How long does a Napa County winery use permit take?
The 2015 Grand Jury report said reviews frequently take 9 to 12 months or more. Completeness review alone can take up to 30 days after submittal and payment.
What is a micro-winery in Napa County?
A small winery permitted under Section 18.08.377 with no more than 5,000 gallons of capacity, 5,000 square feet of enclosed space and 20 daily trips, no marketing events, and at least 75% of its grapes from the property or contiguous parcels.
Can I still get a small winery exemption?
The current packet applies to wineries issued a certificate of exemption before February 22, 1990. A new winery generally goes through a use permit, or the micro-winery track if it qualifies.
Do I need 10 acres to build a winery in Napa?
Under the WDO’s standard rules, yes, for a new winery. Smaller existing wineries operate under older permits or exemptions.
Who approves a Napa winery permit?
The Planning Commission decides new wineries and major modifications. The Zoning Administrator decides micro-winery permits after a noticed hearing, and some smaller changes are handled administratively.
Does a winery use permit expire?
Under Section 18.124.080, a use permit expires two years after approval unless its conditions set a different period.
Can I expand a winery I buy?
Usually through a modification. Larger changes go to the Planning Commission and must meet current rules, including the 75% Napa grape rule for added production.
Planning a winery on a vineyard parcel, or buying one with a permit attached? Our vineyard and winery team can help you collect the permit history and match the land to your plan before you write an offer. For the wider county, see our Napa County guide and the Napa Valley appellation, and read buying a vineyard before you start.
Sources & notes
- Napa County PBES: Use Permit / Administrative Permit Application, Winery Uses (March 2026)
- Napa County PBES: Use Permit, Micro-Winery application (March 2026)
- Napa County PBES: Small Winery Exemption, Existing Winery Uses (March 2026)
- Napa County Grand Jury 2014-2015: Are Napa County wineries following the rules? (May 12, 2015)
- Napa Valley Register: County sunsets winery amnesty program (2026)
- Vinetur: Napa County board votes to end winery code compliance program (March 12, 2026)
- County Code sections (18.08.377, 18.124.080, 18.126.065) are cited as quoted in the county’s March 2026 application packets; the code itself was not opened. Thresholds for minor and very minor modifications should be confirmed with PBES.
Last reviewed October 2026 by Matthew Martinez.
