Equestrian, Ranch & Acreage Properties in Sonoma County

Buying horse, ranch or hobby-farm property in Sonoma County is a systems purchase: the zoning has to allow the animals you plan to keep, and the land needs usable pasture, water, drainage, fencing, barns and safe access as much as the house does.

On parcels of two acres or less, the county allows one horse per 20,000 square feet. Boarding other people’s horses needs a county permit, and some farm buildings are exempt from building permits only on parcels of five acres or more. Here’s what to check, from zoning to manure management.

Zoning and animal limits

Start with the parcel’s zoning on the county’s zoning database. Sonoma County’s agricultural and rural zones include Land Intensive Agriculture (LIA), Land Extensive Agriculture (LEA), Diverse Agriculture (DA), Resources and Rural Development (RRD), and Agriculture and Residential (AR). The county treats raising horses and other livestock as part of agriculture (Permit Sonoma: agricultural uses).

The county’s horse boarding information sheet (revised 2009) sets these limits (Permit Sonoma PJR-036):

Inside a city, municipal rules apply instead, and they’re usually stricter. Confirm the rules in writing for the specific parcel before you buy.

Barns and farm buildings

Sonoma County can exempt buildings used to house farm machinery, animals, supplies or products from a standard building permit, but only on parcels of at least five acres, in certain zones, where an agricultural use already exists, and the building must still meet code (Permit Sonoma: agricultural exemption). Agricultural exempt buildings can’t be used for horse boarding; converting one to a fully permitted building may be required (PJR-036). When you buy, ask which barns, arenas and sheds are permitted, exempt or neither.

Site standards the county expects

• Setbacks: water and feed troughs and horse or livestock buildings 50 feet from the front property line, 20 feet from side and rear lines, and 30 feet from a neighbor’s house.
• Manure: stored on an impervious surface, covered in rain, at least 100 feet from waterways, with horses kept out of streams.
• Stormwater: gutters and downspouts so roof water doesn’t mix with manure, and clean water diverted around barns and paddocks.
• Pasture: rotational grazing, moving horses when grass is grazed down to 3 to 4 inches.
• Boarding facilities: client parking, onsite loading and unloading, dust control on unpaved areas, and restrooms where there are barns or arenas.

These come from the county’s boarding guidance, but they’re good practice on any horse property.

Checklist for horse and ranch property

1. Usable acreage, not total acreage: subtract slopes, creeks, woodland, the house, the septic area and setbacks.
2. Water: well yield in late summer, storage, and troughs; see our wells and septic guide.
3. Drainage: visit in the wet season if you can; mud and standing water decide whether paddocks work year-round.
4. Fencing and gates: type, condition and safety for horses.
5. Barns and arenas: permit status, footing, lighting and condition.
6. Trailer access: turnaround and parking for a truck and trailer.
7. Fire and evacuation: a plan and route to move animals, and defensible space around barns. In High and Very High fire hazard zones, the seller provides a recent defensible-space inspection or you agree to bring the property into compliance within a year (State Fire Marshal).
8. Services: distance to feed stores, a farrier and large-animal veterinarians.
9. Neighbors: the county’s right-to-farm disclosure applies near agricultural land, protecting normal farming practices on both sides of the fence (Permit Sonoma).

Hobby farms

Gardens, orchards, chickens, goats and a few rows of vines face the same limits: zoning, water and labor. Many rural parcels allow agricultural housing for farm workers, and some uses such as small farm stands or farmstays need their own permits (Permit Sonoma). If grapes are part of the plan, read buying a small hobby vineyard.

Williamson Act and protected land

Many ranches are under Williamson Act contracts, which keep land in agricultural use in exchange for lower property taxes and bind later buyers; cancelling a contract costs a fee of 12.5% of current market value (Department of Conservation). Contracted land can’t be used for vacation rentals in the unincorporated county (Permit Sonoma). Ask for the contract and the county’s uniform rules before you buy.

Where to look

Ranch and horse properties come up across the county: in Sonoma Valley around Glen Ellen and Kenwood, around Sebastopol and west county, near Windsor and Healdsburg, and in the hills east and south of Petaluma. For land you plan to build on, see our guide to land, building lots and ADUs; for the market as a whole, the county market report. Ready to look? Contact us and we’ll filter for zoning, water and usable acreage.

Questions people ask

How many acres do I need for a horse?

On small parcels the county allows one horse per 20,000 square feet. In practice, how much pasture you need depends on soil, rainfall, rotation and whether you feed hay.

Can I board other people’s horses?

In LIA, LEA, DA, RRD and AR zones, with a horse boarding zoning permit; group lessons and shows need a use permit.

Do I need a permit for a barn?

Usually, unless it qualifies for the agricultural exemption on a parcel of five acres or more with an existing agricultural use.

Sources & notes

• Permit Sonoma PJR-036: horse boarding; Agricultural building permit exemption; Agricultural uses; Zoning database
• OSFM AB 38 bulletin; Right to Farm disclosure; Williamson Act FAQ; Permit Sonoma: vacation rentals

The horse boarding sheet was last revised in 2009; confirm current rules with Permit Sonoma. Last reviewed October 2026 by Matthew Martinez.