Santa Clara County Rural Land: Hillsides, Coyote Valley, South County
Whether a piece of Santa Clara County land for sale can carry a house depends less on its acreage than on four county questions: is it a legal lot and an approved building site, what density its zoning allows, can it meet access and fire-safe road standards, and can it get water and septic approval. Most rural acreage in the county is unincorporated, so the County of Santa Clara answers those questions, not Morgan Hill, Gilroy or San Jose. A low price per acre may reflect a parcel that fails one of them.
This guide is written for buyers of hillside home sites, South County farmland and Coyote Valley parcels, and for owners preparing to sell them. It focuses on buildability and due diligence. For who does what on county land, the Williamson Act and well and septic rules, see our companion guide to unincorporated Santa Clara County, and for the wider market our Santa Clara County overview.
Legal lot status and building site approval
An assessor’s parcel number is a tax label, not proof that a parcel was lawfully created. Some rural parcels were split by deed long ago, and a parcel created in violation of the Subdivision Map Act can be sold but may not be buildable without conditions.
Certificates of compliance
Under Government Code section 66499.35, the owner of a parcel, or someone buying it under a contract of sale, may request a county determination of whether it complies with the Subdivision Map Act. If it does, the county records a certificate of compliance. If it doesn’t, the county issues a conditional certificate.
The conditions matter to price. The county may impose the conditions that would have applied when the applicant acquired the parcel. If the applicant created the illegal split by a grant and still owns one or more of the parcels, the county may instead impose the conditions that would apply to a division today.
Building Site Approval
The county’s Planning Office says Building Site Approval is required for new residential development, including secondary dwellings, on parcels that are not already approved sites. Lots created by a legal subdivision don’t need it. The review covers driveway and road improvements, use, setbacks, grading, geology, septic, water supply and fire vulnerability, and the application includes a site plan and copies of deeds (county brochure, revised August 2016).
Ask the seller, before you open escrow if possible, for any recorded certificate of compliance, any prior Building Site Approval and the chain of deeds that created the parcel.
How much can be built: rural zoning density
Santa Clara County’s rural base districts are Exclusive Agriculture (A), Agricultural Ranchlands (AR), Hillsides (HS) and Rural Residential (RR). Density in the hillside and ranchland districts is low by design, so many existing parcels are smaller than a new subdivision could create today.
| District | Minimum lot size in the county’s standards table | Setbacks (front, side, rear) | Height |
|---|---|---|---|
| A, A1 Exclusive Agriculture | Set by combining district | 30 ft each | 35 ft, 2 stories |
| AR Agricultural Ranchlands | 160 acres, or by the “20s” slope-density formula | 30 ft each | 35 ft, 3 stories |
| HS Hillsides | 160 acres, or by the “20s” slope-density formula | 30 ft each | 35 ft, 3 stories |
| RR Rural Residential | 5 to 20 acres | 30 ft each | 35 ft, 2 stories |
The table comes from the Planning Office’s development standards sheet dated April 2006, which points to section 2.20.040 of the Zoning Ordinance for the slope-density rules. The ordinance has been revised since (the current chapter is dated April 2024), so treat the table as a starting point and read section 2.20.040 for the parcel’s slope before you count potential lots.
Two practical points follow. Dividing hillside land is rarely as simple as acreage divided by a minimum, so run the slope-density calculation before you pay for lot potential. And an existing smaller parcel may still be buildable if it was lawfully created and passes site approval.
Rural zoning changes in progress
The county is rewriting the A, AR, HS and RR districts. Its project page, checked in October 2026, describes objective standards replacing “local-serving” provisions, standardized agricultural uses, tighter limits on uses in the A district and a proposed CEQA threshold for impacts on valuable farmland. A draft program environmental impact report circulated from July 21 to September 4, 2025, and the amendments were still in draft. If you are buying for a winery, event, equestrian or other non-residential use, ask planning staff how the drafts would treat it.
Access, easements and fire-safe roads
Many rural parcels reach a public road over a private road or a neighbor’s land. A buyer needs to know that the access is legal, that it is wide enough for the county and fire marshal, and who pays to maintain it.
- Recorded easement. Check the title report for an easement that reaches the parcel from a public road, and read its width and permitted uses.
- Road maintenance. Ask for any recorded road maintenance agreement or road association rules, and what owners have paid recently.
- Driveway and road review. Building Site Approval reviews driveway and road improvements, and the county’s guide to building a new house says the Roads and Airports Department reviews driveway access and right-of-way work.
State Minimum Fire Safe Regulations
On August 31, 2021, the Board of Supervisors amended the County Ordinance Code to implement the State Minimum Fire Safe Regulations, and added an appeals process for denied exceptions. The county says the regulations apply on State Responsibility Area land and, since July 1, 2021, in Very High Fire Hazard Severity Zones in the Local Responsibility Area.
The regulations set road standards that a long rural driveway or shared road may not meet. Title 14, section 1273.01 of the California Code of Regulations, operative April 1, 2023, requires roads to have at least two 10-foot traffic lanes, not counting shoulder and striping. The county Fire Marshal’s Office also reviews plans for access and water supply, including whether a water tank, wharf hydrant or residential sprinklers are needed, according to the county’s guide. Road upgrades can be a large share of a project’s cost, so get a civil engineer’s estimate during the contingency period.
Check the parcel’s fire hazard zone on CAL FIRE’s maps, and read our guide to AB 38 defensible space inspections for what a sale in a high hazard zone triggers.
Water and wastewater approvals
Without sewer and a water main, a home site needs two approvals before the county issues a building permit. The county’s new-house guide says sewer or septic clearance is required, and that approval from the Department of Environmental Health is needed where a well or private water system will supply the house.
Well drilling is a separate permit from Valley Water under its Ordinance 90-1, and septic design starts with a site evaluation and soil testing. Our companion county guide, linked above, explains both. For a land purchase, the order matters: test the well and the soils before you commit, because a dry well or failed percolation test can end a site’s buildability.
Diamond may refer you to partners we work with, such as well drillers, septic designers and civil engineers; you’re free to choose any provider.
Coyote Valley parcels
Coyote Valley, between south San Jose and Morgan Hill, mixes city land, county land and conservation purchases, so the jurisdiction of each parcel has to be checked. On December 14, 2021, the Board of Supervisors voted unanimously to amend the General Plan, zoning ordinance and zoning map to protect resources in Mid- and South Coyote Valley, according to the Santa Clara Valley Open Space Authority.
Local News Matters reported that the plan covers about 7,500 acres of unincorporated Coyote Valley and caps the number of single-family homes that can be built outside the San Jose and Morgan Hill city limits. The Open Space Authority said the action aligned with San José City Council decisions prioritizing the valley for agriculture and open space, and that more than 1,400 acres across the valley floor were protected for conservation through purchases by the Authority, Peninsula Open Space Trust and the City of San José.
For a buyer, that means a Coyote Valley parcel should be valued on the homes and uses the 2021 rules allow, not on older expectations of urban development. Our Coyote property guide covers the community itself.
South County farmland: San Martin, Morgan Hill and Gilroy edges
South of Coyote Valley the valley floor opens into farmland and rural home sites around San Martin, with the cities of Morgan Hill and Gilroy at either end. Parcels just outside those cities are usually county land, and whether a city will ever annex or serve them is a separate question for the city and Santa Clara LAFCO.
- Williamson Act contracts are common on farmland and pass to the buyer; see our Williamson Act guide for cancellation and nonrenewal.
- Farmland mapping. The county’s draft rural rules would measure impacts on Prime Farmland, Farmland of Statewide Importance, Unique Farmland and two local categories, so check the parcel on the state’s farmland maps.
- Agricultural use. If you plan to farm, confirm water supply and any well yield, and whether existing barns and ag buildings were permitted.
East and west of the valley, hillside land runs up toward Mount Hamilton and the Santa Cruz Mountains, where Hillsides zoning, steep access roads and fire zones dominate the analysis.
Due diligence steps for a land offer
- Confirm the jurisdiction, zoning and General Plan designation in the county’s Property Explorer.
- Order a preliminary title report and read every easement and recorded agreement.
- Check legal lot status and any certificate of compliance or prior Building Site Approval.
- Have a civil engineer review access against the fire-safe road standards and estimate upgrade costs.
- Test the well, or budget for drilling, and arrange soil testing for septic.
- Check fire, flood, landslide and fault maps, and get insurance quotes.
- Read any Williamson Act contract and confirm the current property tax basis.
- Meet with county planning staff before your contingencies expire.
Our Santa Clara County property evidence workbook gives a place to organize these records. Rural land sales in unincorporated areas pay only the county transfer tax; see our guide to Santa Clara County transfer taxes for how city land differs.
Selling rural land in Santa Clara County
Buyers of land discount for uncertainty, so the most useful thing a seller can do is answer the four buildability questions in writing before listing. Gather deeds, any certificate of compliance, surveys, easements, road agreements, well logs and tests, soil or septic reports, and planning correspondence. Disclose any Williamson Act contract and unpermitted structures.
As a member of the area MLSs, Diamond can list acreage there, and it also contacts likely land buyers through its client database and targeted off-market campaigns within Clear Cooperation rules. See our Santa Clara County seller services for preparation and pricing.
This guide explains county and state land use rules in general and is not legal advice. Before you rely on a parcel’s legal status, access rights or development potential, have a California real estate attorney and a civil engineer review the title, maps and county requirements.
Questions people ask
Can I build a house on any parcel I buy in rural Santa Clara County?
Not automatically. The parcel must be a legal lot, pass Building Site Approval if it isn’t already an approved site, meet access and fire-safe standards, and get water and septic approval.
What is a certificate of compliance?
It is a recorded county determination under Government Code section 66499.35 that a parcel complies with the Subdivision Map Act. A parcel that doesn’t comply gets a conditional certificate, and the conditions must be met before development.
What is the minimum lot size in the Hillsides district?
The county’s development standards sheet lists 160 acres for Hillsides and Agricultural Ranchlands, with density alternatively set by a slope-density formula in Zoning Ordinance section 2.20.040. Confirm the current ordinance text for a specific parcel.
Can I still build in Coyote Valley?
Some homes can be built, but the county’s December 2021 amendments cap single-family homes on about 7,500 unincorporated acres, as Local News Matters reported. Check the parcel’s jurisdiction and current zoning first.
Do fire-safe road rules apply to my parcel?
They apply on State Responsibility Area land and, since July 1, 2021, in Very High Fire Hazard Severity Zones in the Local Responsibility Area, according to the county. Check the parcel on CAL FIRE’s maps.
Is land near Morgan Hill or Gilroy in the city or the county?
Often the county, even with a city mailing address. Look up the parcel in the county’s Property Explorer and ask the city about annexation or services.
If you are weighing a land purchase or preparing acreage for sale, start with our buyer services and we can talk through the parcel’s records with you.
Sources & notes
- California Public Law: Government Code section 66499.35, certificates of compliance
- County of Santa Clara Planning Office: Building Site Approval brochure (rev. August 2016)
- County of Santa Clara Planning Office: Development standards for residential uses by zoning district (April 2006)
- County of Santa Clara: Building a new house (January 2009)
- County of Santa Clara Department of Planning and Development: Rural zoning amendments
- County of Santa Clara Department of Planning and Development: State Minimum Fire Safe Regulations
- Cornell Legal Information Institute: 14 CCR 1273.01, road width
- Santa Clara Valley Open Space Authority: County actions safeguard Coyote Valley farmland and open space (Dec. 14, 2021)
- Local News Matters: Santa Clara County limits development, preserves agriculture in Coyote Valley (Dec. 2021)
- County of Santa Clara Department of Planning and Development: Zoning Ordinance
The county’s 2006 standards table predates the April 2024 revision of the Zoning Ordinance’s rural chapter; confirm figures against the current text.
Last reviewed October 2026 by Matthew Martinez.
