Local zoning · Santa Clara County

Santa Clara County — Land Use

Q: What can I build on an A (Exclusive Agriculture) parcel in unincorporated Santa Clara County?

Agriculture and livestock are allowed by right, with small-scale ag processing also by right. Many other uses (e.g., bed and breakfasts, golf courses, dairies) require a Use Permit/ASA. Dimensional standards include 30 ft setbacks, 35 ft height, and 100 ft along scenic roads. See § 2.20.020 and § 2.20.030.

Q: How do slope-density rules affect lots in AR, HS, and RR?

They cap the number of dwellings based on average slope, ranging from 1 unit/5 acres in RR (gentle slopes) up to 1/160 acres in AR/HS (steep slopes). HS also requires clustering, with 2-acre minimum cluster parcels. See § 2.20.040.

Q: Do I need design review in hillside or viewshed areas?

If your parcel carries -d1 (Valley Viewshed) or -d2 (Milpitas Hillsides), design review applies and some uses may be disallowed. Check the -d map and § 3.20.010, and any -d notes in the applicable use table.

Q: Are ADUs allowed in unincorporated areas?

Yes. ADUs and JADUs are permitted in rural and urban residential districts (generally by right) and in CN/CG/OA commercial districts. See § 4.10.015 and the district use tables (§ 2.20.020, § 2.30.020, § 2.40.020).

Q: What is a “planning clearance” versus a Use Permit?

A planning clearance is a ministerial sign-off for “C” uses, has no hearing, and is not appealable. Use Permits (U) are discretionary, require hearings, and can be appealed per Table 5.10-1. See § 5.20.240 and § 5.10.020.

Q: What are the basic rural setbacks and heights?

In A/AR/HS/RR, front/side/rear setbacks are 30 ft, with 100 ft along scenic roads. Maximum height is 35 ft (2–3 stories depending on district). See Table 2.20-3 in § 2.20.030.

Q: Can commercial districts include housing?

Yes. Multi-family housing and mixed-use residential are allowed in CN, CG, and OA. Apply the district use table and the commercial/industrial standards in Table 2.40-2. See § 2.40.010–.030.

Q: How do the Stanford OS/F and SCA districts work?

OS/F allows low-intensity open-space and field research uses with specific criteria; SCA focuses on conservation and generally prohibits new permanent buildings. See § 2.50.010 and § 2.50.040.

Land Use under the Santa Clara County local zoning and planning code, with the controlling citations.

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Last reviewed: July 6, 2026

Overview

This page explains how land use works in unincorporated areas of Santa Clara County under the County Zoning Ordinance. It focuses on what each zoning district permits, when a use needs a planning clearance or discretionary permit, and the core dimensional standards that govern whether a use fits on a parcel. For related topics like parking, design review, overlay districts, and development standards, see the linked guides.

If a use is not listed in the applicable land use table for your base district, it is not allowed in that district. The zoning tables use letter codes: “R” (by right), “C” (planning clearance), “S” (special permit), “A” (Architecture and Site Approval), “U” (Use Permit + ASA). See § 2.20.020 and § 2.40.020.

How land use is organized

Base districts are grouped into: rural (A, AR, HS, RR), urban residential (R1, R1E, RHS, R1S, R3S, R2, R3), commercial/industrial (CN, CG, OA, ML, MH), and special purpose (A1, RS, OS/F, SCA). See § 2.20.010, § 2.30.010, § 2.40.010, and § 2.50.010.
The rural districts share a common development standards table with typical setbacks of 30 ft (front/side/rear) and 35 ft height, plus 100 ft along designated scenic roads. See Table 2.20-3 in § 2.20.030.
Where slopes are significant, the rural districts (AR, HS, RR) use a slope-density formula to determine maximum dwelling units and minimum parcel sizes; HS also requires clustering. See § 2.20.040.

Rural Base Districts (unincorporated areas)

A — Exclusive Agriculture

Purpose: preserve and encourage long-term agriculture; site non-ag uses only if they support agriculture and don’t require urban services. See § 2.20.010(A) and the agricultural preservation criteria in § 2.20.050.
Typical permitted uses
- Agriculture and livestock by right; small-scale agricultural processing by right; medium-scale processing with ASA; large-scale with Use Permit. See Table 2.20-2 in § 2.20.020.
- Bed and breakfast inns, camps/retreats, cemeteries, dairies, feed lots, and golf courses require discretionary approvals (generally Use Permit/ASA). See Table 2.20-2.
Key dimensional standards
- Setbacks: 30 ft front/side/rear; 100 ft on scenic roads. Height: 35 ft/2 stories. See Table 2.20-3 in § 2.20.030.
Where it applies: areas with General Plan designations Agriculture: Large/Medium Scale and Open Space Reserve. See § 2.20.010(A).

AR — Agricultural Ranchlands

Purpose: preserve ranching and rural character; allows ranching/agriculture, low-intensity recreation, resource extraction; very low-intensity residential and limited commercial/industrial if rural-serving. See § 2.20.010(B).
Typical permitted uses
- Single-family residences by right; rural agriculture/livestock by right; many non-residential rural uses require Use Permit/ASA. See Tables 2.20-1 and 2.20-2 in § 2.20.020.
Key dimensional standards
- Without slope-density: 160 acres minimum for subdivision; with slope-density, density ranges from 1 unit/20 acres (<10% slope) to 1/160 acres (≥50% slope). See § 2.20.030 and § 2.20.040.
- Setbacks: 30 ft front/side/rear; 100 ft scenic roads; height 35 ft/3 stories. See § 2.20.030.

HS — Hillside

Purpose: protect mountainous lands, watersheds, habitat and scenic views; allow very low-density residential, agriculture/grazing, low-intensity recreation; encourage clustering. See § 2.20.010(C).
Typical permitted uses
- Agriculture and single-family residences by right; many other uses require special permits or Use Permits. See Tables 2.20-1 and 2.20-2.
Key dimensional standards
- Without slope-density: 160 acres minimum for subdivision; with slope-density and cluster permit: 1 unit/20 acres (<10% slope) to 1/160 acres (≥50% slope); cluster parcels may be as small as 2 acres. See § 2.20.030 and § 2.20.040.
- Setbacks: 30 ft front/side/rear; 100 ft scenic roads; height 35 ft/3 stories. See § 2.20.030.

RR — Rural Residential

Purpose: permit rural residential development with compatible agricultural/open space uses; allow only local-serving commercial/industrial/institutional. See § 2.20.010(D).
Typical permitted uses
- Single-family residences and ADUs by right; small-scale emergency shelters permitted; many institutional uses require Use Permit. See Tables 2.20-1 and 2.20-2.
Key dimensional standards
- With slope-density: 1 unit/5 acres (<10% slope) to 1/20 acres (≥50% slope; clustering optional). See § 2.20.040.
- Setbacks: 30 ft front/side/rear; 100 ft scenic roads; height 35 ft/2 stories. See § 2.20.030.

Urban Residential Base Districts (unincorporated areas)

These apply within city urban service areas on unincorporated “islands” or fringe areas.

R1 — One-Family Residence; R1E — One-Family Residence—Estate; RHS — Urban Hillside Residential; R1S and R3S — Stanford Campus Residential; R2 — Two-Family; R3 — Multi-Family

Purpose: provide residential districts consistent with the applicable city’s General Plan. See § 2.30.010.
Typical permitted uses
- Single-family dwellings by right in R1, R1E, RHS, and permitted/ASA in campus districts; two-family by right in R2; multi-family requires ASA in R3. ADUs and JADUs are generally by right; expanded home occupations require a Special Permit. See Table 2.30-1 in § 2.30.020.
- Note for RHS: on 2.5-acre+ lots, all agricultural uses allowed by right in HS are also allowed. See Table note under § 2.30.030.
Key dimensional standards
- Development standards are in Table 2.30-3 (§ 2.30.030) — verify setbacks, lot coverage, height, and any city-specific provisions. Not found in retrieved materials: specific numeric setbacks and heights for each urban residential district.

For ADUs, see the County’s ADU rules in § 4.10.015 and our California ADU law overview.

Commercial and Industrial Base Districts (unincorporated areas)

CN — Neighborhood Commercial; CG — General Commercial; OA — Administrative/Professional Office; ML — Light Industrial; MH — Heavy Industrial

Purpose: provide appropriate commercial/industrial uses within urban service areas; multi-family and mixed-use are also allowed in CN/CG/OA. See § 2.40.010.
Typical permitted uses
- ADUs/JADUs allowed in CN/CG/OA; many commercial services are A/U depending on intensity; industrial uses concentrate in ML/MH. See Table 2.40-1 in § 2.40.020.
Key dimensional standards
- Industrial minimum lot area: 10,000 sq ft; maximum heights up to 65 ft (district dependent); setbacks from adjacent residential zones vary by district. See Table 2.40-2 in § 2.40.030.
- Parking is per Chapter 4.30; see our parking guide.

Special Purpose Base Districts (unincorporated areas)

A1 — General Use; RS — Roadside Services; OS/F — Open Space and Field Research; SCA — Special Conservation Areas

Purpose: “non-standard” districts for location-specific needs, including Stanford lands (OS/F, SCA). See § 2.50.010.
Typical permitted uses
- A1 is flexible: general residential/agricultural by right; other uses via Use Permit/ASA. RS allows highway-serving clusters with careful siting. OS/F prioritizes open space and field research; certain low-intensity activities are permitted by right. SCA limits activity to conservation, habitat, field studies, and similar — no new permanent buildings. See § 2.50.010, § 2.50.020 and § 2.50.040.

Combining/Overlay Districts that affect land use

Slope-Density Combining (-s): adjusts allowable units/parcel sizes by slope per formulas; minimum parcel sizes range from 1–20 acres depending on district and slope. See Chapter 3.10 and its table.
Design Review (-d): triggers design review in the Santa Clara Valley Viewshed (-d1) and Milpitas Hillsides (-d2). Some uses are not permitted in -d1/-d2. See § 3.20.010 and notes in use tables. Also see our design review and overlay districts guides.
Historic Preservation (-h): example, New Almaden (-h1) limits uses to single-family, agriculture, limited community uses, with special findings for historic conversions. See § 3.50.090. Also see historic preservation.

Permit types and who decides

Planning clearance is ministerial for certain “C” uses; no appeal. See § 5.20.240.
Discretionary permits and decision makers: ASA (Zoning Administrator), Special Permit (ZA), Use Permit (Planning Commission); appeals go to PC or Board per Table 5.10-1. See § 5.10.020.

Decision-Focused Snapshot

The most common questions boil down to “Is my use allowed?” and “What basic site limits apply?” Use this quick matrix, then confirm details in the cited tables/sections.

District	Typical “by right” uses	Commonly discretionary uses	Key site limits	Code Reference
A	Agriculture; small-scale ag processing	B&Bs; dairies; golf; feed lots	30 ft setbacks; 35 ft height; 100 ft scenic road	§ 2.20.020 Tables 2.20-1/-2; § 2.20.030 Table 2.20-3; § 2.20.050
AR	Single-family; agriculture/livestock	Retreats; cemeteries; farmers’ markets	160 acres min (no slope-density); slope-density ranges; 30 ft setbacks; 35 ft height	§ 2.20.020; § 2.20.030; § 2.20.040
HS	Single-family; agriculture	Seasonal outdoor entertainment; golf	Slope-density with cluster; 30 ft setbacks; 35 ft height	§ 2.20.020; § 2.20.040; § 2.20.030
RR	Single-family; ADUs; small shelters	Larger institutional uses	Slope-density; 30 ft setbacks; 35 ft height	§ 2.20.020; § 2.20.040; § 2.20.030
R1/R2/R3	Homes, ADUs/JADUs, limited care	Expanded home occupations (S), multifamily (ASA)	See Table 2.30-3 (verify)	§ 2.30.010–.030
CN/CG/OA	Retail/office; ADUs/JADUs	Adult uses (U in CG); service stations (U)	Height up to 65 ft (varies); setbacks near residential	§ 2.40.010–.030; Tables 2.40-1/-2
ML/MH	Light/heavy industrial	Broadcasting; contractors’ facilities	10,000 sf min lot; up to 65 ft height; screening/landscaping	§ 2.40.030–.040

Also check signage and landscaping and screening where applicable.

Notes and special rules often missed

“Local-serving” scale caps: some rural uses must be sized to primarily serve rural residents; large facilities require findings against a 75th-percentile baseline. See § 2.20.090.
Emergency shelters: small-scale by right in RR and certain urban/commercial districts; other scales require Use Permits; San Martin (-sm) has special rules. See Tables 2.20-2 and 2.40-1; note in Table 2.20 that emergency shelters relate to -sm.
Scenic roads: add a 100 ft front setback in rural districts. See Table 2.20-3.
-os designator: parcels with -os are restricted to certain multi-family or limited mixed-use paths under Chapter 3.75; standards tables exempt those parcels. See notes in § 2.20.030 and § 2.40.030.
Procedures and appeals: who decides ASA, Special Permit, Use Permit, and where appeals go are listed in Table 5.10-1; “C” uses use planning clearance with no appeal. See § 5.10.020 and § 5.20.240.
Nonconforming situations use separate rules; see nonconforming uses and variances and exceptions.

Checklist

Confirm your parcel is in unincorporated Santa Clara County and identify the base zoning district on the County map. See zoning.
Look up your district’s land use table and confirm your use is listed (and whether it’s R, C, S, A, or U). § 2.20.020, § 2.30.020, § 2.40.020, § 2.50.020.
Check overlays/combining districts (-d, -s, -h, -os, -sm) that may add limits or review. Ch. 3.10; § 3.20.010; § 3.50.090.
Confirm dimensional standards (setbacks, height, lot size) and any slope-density or cluster requirements. § 2.20.030–.040; § 2.30.030; § 2.40.030.
Identify any supplemental use regulations that apply (ADUs, community care, home occupations, signage, golf, etc.). Ch. 4.10, 4.20, 4.40.
Determine the approval path: planning clearance vs. ASA/Special Permit/Use Permit and the review authority. § 5.10.020; § 5.20.240.
Check if design review or landscaping and screening standards apply.
For structures, remember separate compliance with the California Building Standards Code even though this page covers zoning only.

Risks & Ambiguities

Issue	Why it matters	What to verify
“Local-serving” scale in rural areas	Oversized rural facilities may be denied or conditioned; projects above the 75th percentile need extra findings	Whether your proposed size exceeds the Local Serving Data thresholds under § 2.20.090
Slope-density/cluster rules	Density and parcel size can change dramatically with slope; HS requires clustering	Average slope calculation and resulting units; whether a Cluster Permit is required under § 2.20.040 and Ch. 5.45
-os designator on parcel	Changes allowed uses and exempts you from standard district tables	Whether your parcel carries the -os designator and the applicability of Ch. 3.75 notes in § 2.20.030/§ 2.40.030
Viewshed (-d1) and hillside (-d2) overlays	Some uses not permitted; design controls apply	Presence of -d1/-d2; use notes in tables referencing -d districts and § 3.20.010
Historic (-h) districts	Narrower use lists and special findings	Whether your site is within New Almaden (-h1) and § 3.50.090 allowances/finding criteria
Industrial adjacency to residences	Additional setbacks/height modulation to buffer impacts	If your CN/CG/OA/ML/MH site abuts residential, apply Table 2.40-2 rules; check ASA flexibility notes in § 2.40.030
Permit path vs. timeline	ASA/Use Permits require hearings; clearances do not and are not appealable	Whether your use is “C” vs. “A/U/S” and decision-maker per § 5.10.020 and § 5.20.240

Information Gaps

Specific numeric setbacks/height/lot coverage by district for the urban residential series (R1, R1E, RHS, R1S, R3S, R2, R3) were not present in the retrieved excerpts; they are in Table 2.30-3, but values were not visible. Verify with the jurisdiction.

Plain-English Summary

Zoning in unincorporated Santa Clara County tells you what you can do on your land and which approvals you need. First, find your base district, then check the district’s land use table to see if your use is allowed by right, needs a planning clearance, or a public hearing. Rural areas have extra slope-based limits and often require clustering; urban islands and commercial/industrial areas have their own permitted use lists and buffers. Overlays like viewshed (-d1), hillside (-d2), or historic (-h) can further narrow what’s allowed.

Source References

§ 2.20.010 (Rural base district purposes)
§ 2.20.020; Tables 2.20-1 and 2.20-2 (Rural permitted uses)
§ 2.20.030; Table 2.20-3 (Rural development standards)
§ 2.20.040; Table 2.20-4 (Slope-density)
§ 2.20.050 (Agricultural preservation criteria)
§ 2.20.090 (Local-serving scale criteria)
§ 2.30.010–.030; Table 2.30-1 (Urban residential purposes/uses; standards table location)
§ 2.40.010–.030; Tables 2.40-1 and 2.40-2 (Commercial/industrial purposes/uses/standards)
§ 2.50.010–.040; Table 2.50-1 (Special purpose purposes/uses/OS-F criteria)
Ch. 3.10; Table 3.10-2 (Slope-Density Combining)
§ 3.20.010 (Design Review -d) and -d1/-d2 notes in tables
§ 3.50.090 (Historic Preservation -h1 New Almaden)
§ 4.10.015 (ADUs), § 4.10.090 (Community care), § 4.10.140–.150 (Golf uses), § 4.10.180 (Home occupations)
§ 5.10.020; Table 5.10-1 (Review authority) and § 5.20.240 (Planning clearance)
See also: County zoning overview, zoning, development standards, overlay districts, design review, parking, nonconforming uses, variances and exceptions, landscaping and screening, California housing laws, California Building Standards Code.

Sources

Retrieved passages

Santa Clara County Zoning Code (Chapter 3.90) High relevance
Santa Clara County Zoning Code (Chapter 3.75) High relevance
Santa Clara County Zoning Code (Chapter 5.45) High relevance
Santa Clara County Zoning Code (Chapter 3.90) Medium relevance
Santa Clara County Zoning Code (§ 2) Medium relevance
Santa Clara County Zoning Code (§ 2.20.060) Medium relevance
Santa Clara County Zoning Code (§ 3.50.090.) Medium relevance
Santa Clara County Zoning Code (§ 4.10.180) Medium relevance
Santa Clara County Zoning Code (§ 2.50.010.) High relevance
Santa Clara County Zoning Code (§ 2.20.090) Medium relevance
Santa Clara County Zoning Code (§ 2.20.030.) Medium relevance
Santa Clara County Zoning Code (Section 2.20.060) Medium relevance
Santa Clara County Zoning Code (Chapter 5.60) Medium relevance
Santa Clara County Zoning Code (§ 3) Medium relevance
Santa Clara County Zoning Code (Chapter 2.50.) Medium relevance

Cited sections

Official Santa Clara County code library

Frequently asked questions

What can I build on an A (Exclusive Agriculture) parcel in unincorporated Santa Clara County?