Skip to main content
You are the owner of this article.
You have permission to edit this article.
Napa County explores limiting agricultural preserve McMansions

Napa County explores limiting agricultural preserve McMansions

Rural housing

Napa County is exploring whether to have a one-acre development envelope for new homes in the agricultural preserve to preserve land for farming. The above sign can be seen on Linda Vista Avenue north of the city of Napa.

Napa County is considering a one-acre development limit for new homes allowed amid the agricultural preserve, a move to help protect prime Napa Valley farmland.

County law allows a house and related uses on each rural parcel. Presently, there is no limit as to how big a house can be if it complies with various setbacks, such as for streams. 

In some cases, a mansion and landscaping and sports courts cover two acres and more. County Supervisor Diane Dillon has voiced concern about the situation.

“It’s one of those things that slowly, slowly, slowly can erode the ag preserve,” she said last week. “That’s why it’s a good thing to put a control in place now.”

Some homes in the agricultural preserve are small and quaint farmhouses. Others are imposing, such as a two-home Tuscan estate described by Zillow as having 11 bedrooms, 12 bathrooms and a bridged swimming pool.

The county recently released a proposed law that would still allow big homes, but with limits. A new home, a second unit, gazebos, deck, trellises, tennis courts, pools, parking area, landscaping and other features would in most cases have to be within one contiguous acre.

An acre is slightly smaller than the city of Napa's Monarch and Summerfield parks. The typical city neighborhood park is closer to two or three acres.

Among the features not included for the one-acre building envelope calculation would be wells and septic systems. Those desiring home sites bigger than an acre could seek a use permit from the county Zoning Administrator at a public hearing.

The proposed one-acre limit would not apply to new homes in the agricultural watershed zoning district. That district covers most parts of rural Napa County away from the Napa Valley floor, such as the mountains framing the valley.

Rather, it would focus on the agricultural preserve established by the county in 1968 and expanded in subsequent years to today's 31,609 acres. The goal was to keep the heart of Napa Valley wine country from being paved over.

Agricultural preserve zoning helped keep city-style growth away from rural Napa Valley farmland. But it didn’t stop new wineries and rural homes from being built.

About six years ago, local officials had new concerns about prime agricultural land being developed. The county’s Agricultural Protection Advisory Committee (APAC) held a series of 2015 meetings.

New winery developments are limited to 15 acres or 25% of a parcel, whichever is less. The commission's attention turned to new homes.

“The biggest threat to the valley isn’t wineries; it is the proliferation of mansions,” the group’s report states at one point, though not necessarily as a majority opinion.

In March 2016, the Board of Supervisors began exploring a possible housing footprint limit as part of the many APAC ideas. The conversation came up again at a November 2018 Board of Supervisors meeting.

The next step will be a proposed law going to the Napa County Planning Commission. That could happen in October. Ultimately, the Board of Supervisors will decide the issue.

Hot air balloons often land in the city of Napa's Vine Hill Park. Here's what it looked like on a recent day.

Catch up on Napa County's top news stories

In case you missed it, here is a look at the most-read stories on

Get unlimited digital access to the Napa Valley Register for just $1 for your first 6 months! Enjoy every article without restrictions and find tons of subscriber-only perks, such as access to our daily eEdition. Click here for details!

You can reach Barry Eberling at 256-2253 or

Get local news delivered to your inbox!

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Napa County Reporter

Barry Eberling covers Napa County government, transportation, the environment and general assignments. He has worked for the Napa Valley Register since fall 2014 and previously worked 27 years for the Daily Republic of Fairfield.

Related to this story

Get up-to-the-minute news sent straight to your device.


News Alerts

Breaking News