Local zoning · Solano County

Solano County — Development Standards

Q: What can I build on an R-1 or R-TC lot in unincorporated Solano County?

You must consult the specific R subdistrict table that applies (for example R-TC-D4, R-TC-MU). Typical allowed uses include single-family homes, accessory structures and accessory dwelling units (subject to ADU rules). Dimensional limits (front/side/rear yards, height 35 ft ) and minimum lot area are in the district’s development table (see Table 28.32C / § 28.32.30 ) .

Q: What are Solano County setback requirements?

Setbacks are set per zoning district in each district’s development table (e.g., Table 28.23B, 28.22B, 28.41B); common examples include front 30 ft (or 50 ft from centerline) in many agricultural districts, side 20 ft in ag districts, and 35 ft height caps. Always measure setbacks using the rules in § 28.97 ; mapped building lines can override table numbers .

Q: How high can I build in unincorporated Solano County?

Most base districts list a 35 ft height limit in the district development tables; some commercial districts permit higher heights with a use permit (e.g., C-S up to 50 ft with a permit). Exceptions for airport flight zones and other special areas are addressed in § 28.93 and § 28.99 — verify if your parcel is within such an area .

Q: Do accessory buildings have different setbacks?

Yes. Many agricultural and rural accessory-building tables require accessory buildings to be located 60 ft from the front property line (or on the rear 50% of the lot) and often set 20 ft side/rear accessory setbacks and 10 ft between structures ; consult Table 28.23C, Table 28.31C, or Table 28.43C as applicable .

Q: Are there floor area ratio (FAR) or lot-coverage limits?

Some districts (notably portions of the Suisun Valley tables) list FAR values (e.g., 0.5 with sewer, 0.3 without). However, FAR or lot-coverage is not consistently listed for every district. If the district table does not show a FAR/lot coverage cap, check overlays/PP plans or verify with the County. Refer to Table 28.23B for Suisun Valley examples § 28.23.40 .

Q: Does an overlay change these standards?

Yes — Policy Plan Overlays (-PP) and other overlays (like the Travis Reserve Area) explicitly can define different setbacks, heights, coverage, and permitted uses. The overlay must be shown on the zoning map and the overlay text will enumerate its own standards; see § 28.68 and the overlay list in § 28.60 .

Q: Do I need design review or architectural approval?

Certain uses/districts require Architectural Approval or design review; district tables refer to § 28.102 for when Architectural Approval is required (for example many Suisun Valley ATC/ATC-NC projects and Policy Plan developments) — consult § 28.102 and the county Design Review page early in your project planning .

Q: Where are parking requirements specified?

Parking minimums are cross-referenced in the district development tables to § 28.94 ; Suisun Valley has special parking provisions (including parking districts) noted in district text. See Table notes in the district sections and the county Parking page .

Q: Can I build an ADU and what setbacks apply?

ADUs are governed by a mix of local ordinance references and state ADU law. The county’s accessory rules and accessory-building tables apply, but state ADU statutes limit what local agencies may require (e.g., minimal setbacks for small ADUs). Always cross-check local accessory-building table numbers with current California ADU law and verify with county staff .

Q: What if my project needs a variance or exception?

Many districts allow height or setback increases only by discretionary permit (use permit or variance). The district tables note when additional height requires a use permit (e.g., several commercial zones) — consult that district’s standards and the county Variances and Exceptions process and confirm requirements in the ordinance (e.g., the use-permit references within the district sections) .

Development Standards under the Solano County local zoning and planning code, with the controlling citations.

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Last reviewed: July 3, 2026

Overview

This page summarizes the development standards that govern building siting, maximum heights, setbacks, accessory-structure placement, lot-area minima, and basic intensity controls in the unincorporated areas of Solano County under the county Zoning Ordinance (Chapter 28 / commonly referenced as "Title 28" zoning regulations). It synthesizes where each district’s dimensional rules live in the ordinance and where to look for measurement rules, exceptions, and overlay requirements. For parking, design review, and other procedural items referenced below see the county pages on Solano County Parking, Solano County Design Review, and Solano County Overlay Districts.

Note: this summary applies only to development in Solano County’s unincorporated areas. Confirm parcel-specific standards with the Department of Resource Management; the code allows map-specific building lines and overlays to alter the base standards. See setback measurement rules at § 28.97 and height exceptions at § 28.93 for measurement and exceptions .

How the code organizes development standards (quick)

District-level dimensional standards (setbacks, height, lot area) are given in tables inside each zoning section (for example Tables 28.23B/28.23C for Suisun Valley; Table 28.22B for Suisun Marsh; Table 28.41B for Commercial districts) — consult the table that matches your zoning district and the measurement rules in § 28.97 .
Accessory building standards are often in separate tables (e.g., Table 28.23C, Table 28.31C, Table 28.43C) and may set larger front setbacks or additional separation rules .
Overlays (Policy Plan Overlay, Travis Reserve Area, Park, etc.) can replace or augment base-district standards and require special findings or a development plan § 28.68 and §§ listed in the overlay index (see the overlay list in § 28.60) .

District-by-district reference (selected, decision-relevant districts)

Each subsection below gives the district name (bold), purpose, typical allowed uses, the key dimensional standards you will actually apply, and where those numbers are codified.

A-SV-20 (Agriculture — Suisun Valley)

Purpose: Preserve agricultural character and permit agriculture and accessory tourism-supporting uses; standards tailored to protect vineyards and small farms. See § 28.23.10–28.23.40 for purpose, uses and standards .
Typical permitted uses: crop production, farm buildings, limited agri-tourism (see Table 28.23A in the ordinance) .
Key dimensional standards (general): Minimum lot area typically 20 acres (varies with water/sewer) and Height limit 35 ft. Front setback 30 ft (but at least 50 ft from the street centerline); Side 20 ft; Rear 25 ft; Between structures 10 ft. FAR / lot coverage for main buildings: 0.5 with water/sewer, 0.3 without (Table 28.23B / 28.23C) — see § 28.23.40 and Table 28.23B/C .
Accessory buildings: detached accessory builds may have front placement restrictions (e.g., 60 ft from front property line or rear 50% of lot), and height 35 ft (see Table 28.23C) .

ATC and ATC-NC (Agriculture — Tourist Center / Neighborhood Commercial within Suisun Valley)

Purpose: Allow small agri-tourism centers and associated retail/services while protecting farm character. See § 28.23.12–28.23.40 .
Typical uses: tasting rooms, farm stands, small food service, accessory lodging (conditional/administrative permits apply).
Key dimensional standards: Front: ranges from none to 25 ft (district/lot-specific); Side: often none; Rear: often none to 15 ft; Height: generally 35 ft; FAR: 0.5 w/ sewer, 0.3 w/o (Table 28.23B/28.23C) — see § 28.23.40 .
Design review: ATC development is subject to Suisun Valley design guidelines and may require Architectural Approval per § 28.102 . See the county’s design review page for process steps.

A-SM-80 / A-SM-160 (Agricultural — Suisun Marsh)

Purpose: Protect marsh/rural/agricultural lands (Suisun Marsh); development is tightly constrained. See § 28.22.30 and Table 28.22B .
Typical uses: agriculture, accessory farm buildings, limited structures supporting marsh management.
Key dimensional standards (Table 28.22B): Minimum lot area large (e.g., 80–160 acres depending on subdistrict); Front setback 30 ft (or 50 ft from centerline of street); Side 20 ft; Rear 25 ft; Between structures 10 ft; Height limit 35 ft. See § 28.22.30 and Table 28.22B .
Additional requirement: Suisun Marsh development may also require a Marsh Development Permit under Chapter 28.104 and State Suisun Marsh law (see Table notes in § 28.22.30) .

R-TC family (Residential — Traditional Community districts, incl. R-TC-D4, R-TC-D6, R-TC-MU)

Purpose: Traditional neighborhood residential districts with varying densities and mixed-use options; see § 28.32.10–28.32.30 and Tables 28.31/28.32/28.32C .
Typical uses: single-family homes, duplexes (where allowed), accessory dwelling units.
Key dimensional standards vary by R-TC subtype (see Table 28.32C / Table 28.31C): examples include height 35 ft, front setbacks that may be 0–25 ft depending on R-TC subdistrict, side setbacks often as low as 5 ft in higher-density R-TC districts, and between structures typically 10 ft. Check the specific R-TC subdistrict table for exact numbers (§ 28.32.30 and Table 28.32C) .
ADUs: The ordinance references accessory dwelling rules and the county must follow state ADU law; local setback and height cross-checks remain (see § references where ADUs are listed and verify against California ADU law) .

R-R family (Rural Residential — R-R 2-1/2, R-R 5, R-R 10)

Purpose: Low-density rural residential; see Table 28-31C and § 28.31/28.32 references .
Typical uses: single-family dwellings, accessory farm structures.
Key dimensional standards (Table 28.31C): typical front setbacks 60 ft or rear 50% for accessory buildings, side 10–20 ft (varies), height 35 ft (see table), between structures 10 ft. Accessory building placement rules and stables have larger required separations (see Table 28.31C and § 28.72.10B) .

C-H / C-N / C-R / C-O / C-S / C-R-L (Commercial districts)

Purpose: Commercial and mixed commercial uses with district-specific intensity/compatibility rules; see § 28.41.10–28.41.30 and Table 28.41B .
Typical permitted uses: retail, service, limited office; some C districts allow more intense commercial/industrial uses.
Key dimensional standards (Table 28.41B): Front setbacks vary — C-H 20 ft, C-O 15 ft, C-N none (with exceptions where adjacent to R/A districts); Sides often none but with buffers where abutting residential; Rear often none (C-O = 10 ft; adjacent to residential = 15 ft); Between structures 10 ft; Height: commonly 35 ft (higher heights with a use permit; C-S up to 50 ft with permit; C-O requires increased yards for extra height) — see § 28.41.30 and Table 28.41B .
Buffering: where a commercial district abuts residential, the code requires increased side/rear yards, walls/fences, and screening (see Table 28.41B) .

AS (Agricultural Service) and other agricultural accessory rules

Accessory buildings in AS/AG districts: front 60 ft or rear 50% of lot, sides 20 ft, rear 20 ft, between structures 10 ft, height 35 ft; see Table 28.43C and § 28.71.20(B) for accessory agriculture building standards .

Overlay districts (Policy Plan Overlay -PP, Travis Reserve Area TRA, Park P)

Policy Plan Overlay (-PP) establishes a development plan that can replace base district rules; it must enumerate height, coverage, setbacks and other standards and will be shown on the map as “-PP” with a serial number — see § 28.68 and § 28.60 for overlay mechanics .
Travis Reserve Area (TRA) Overlay prohibits new residential and limits accessory ag structures to small footprints/low heights (e.g., accessory structures < 2,500 sq. ft. and < 25 ft tall are allowed) — see the Travis Reserve language in the overlay text (overlay index and overlay standards) .
Park (P) District development standards are listed under § 28.61 (uses and permit requirements) — consult the P district tables for dimensional requirements .

Decision-relevant standards (compact table)

District (example)	Front Setback	Side Setback (each)	Rear Setback	Height Limit	FAR / Lot Coverage	Code Reference
A-SV-20	30 ft (or 50 ft from street centerline)	20 ft	25 ft	35 ft	0.5 w/ sewer; 0.3 w/o	Table 28.23B / § 28.23.40
ATC / ATC-NC	None–25 ft (varies)	None (varies)	None–15 ft	35 ft	0.5 / 0.3	Table 28.23B / § 28.23.40
A-SM-80 / A-SM-160	30 ft (or 50 ft from street centerline)	20 ft	25 ft	35 ft	Not shown in table	Table 28.22B / § 28.22.30
R-TC-D4 / R-TC-MU	0–25 ft (subdistrict-specific)	5–15 ft (subdistrict-specific)	10–15 ft	35 ft	See district table	Table 28.32C / § 28.32.30
C-H / C-N / C-O	20 ft / None / 15 ft	None (may require buffer if abutting R/A)	None (C-O = 10 ft; adj R = 15 ft)	35 ft (higher with permit; C-S up to 50 ft)	Not shown in table	Table 28.41B / § 28.41.30

(Use the specific table for the exact subdistrict of your parcel; see setback measurement rules § 28.97 and height exceptions § 28.93) .

Key cross-references and procedural notes

Setback measurement and allowed projections into setbacks: § 28.97 .
General height rules and exceptions (airports, special permits): § 28.93 .
Parking requirements for all districts: § 28.94; consult the county Parking page and Table references in each district .
Architectural Approval / Design Review: § 28.102 (applies in districts/uses that require Architectural Approval) — see the county Design Review page for process guidance .
Signs, screening, and fencing requirements are cross-referenced from each district’s table to § 28.96 and landscaping/screening standards — see Solano County Signage and Solano County Landscaping and Screening pages for implementation details .
Overlays (Policy Plan Overlay -PP, Travis Reserve Area TRA) can supersede the district standards and create parcel-specific standards; they are established under § 28.68 and listed in the overlay index § 28.60 .

Checklist (what an applicant must confirm / provide)

Identify the zoning district for the parcel and the exact subdistrict (e.g., A-SV-20, R-TC-D4). Verify any overlay (-PP, TRA, etc.) that modifies standards (see § 28.60 / § 28.68) .
Read the district’s development table (e.g., Table 28.23B, 28.22B, 28.41B) and pull the numeric values for front/side/rear setbacks, between-structure separation, height limit, and minimum lot area .
Confirm setback measurement rules and allowed projections per § 28.97 (this affects porch projections, eaves, stairs) .
Check parking requirements in § 28.94 and prepare parking plan accordingly; verify if a shared parking district is allowed (Suisun Valley has special provisions) .
Determine whether Architectural Approval / Design Review (§ 28.102) or other discretionary approvals are required (e.g., for ATC, PP overlays) and schedule pre-application if needed .
For accessory buildings and ADUs, confirm the accessory-building tables (e.g., Table 28.23C, Table 28.31C, Table 28.43C) and compare to state ADU rules — see California ADU law .
If seeking taller than the base height, identify what discretionary approvals (use permit, findings) are needed per the district (many require a use permit) — check the district table and § 28.93 for conditions .
Verify whether the parcel is within any special regulatory areas (Suisun Marsh, Watershed, Airport flight path, Travis Reserve Overlay) that add constraints (see Table notes and overlay sections) .

Risks & Ambiguities

Issue	Why it matters	What to verify
Map building lines and parcel-specific building lines	District tables often say “unless otherwise indicated by building lines on the zoning maps.” A mapped building line can change your front setback significantly.	Verify the official zoning map and any recorded building lines for your parcel with the Department of Resource Management (Zoning Map) — see § 28.97 for measurement rules .
Overlay districts (PP, TRA, etc.)	Overlays can replace base-district setbacks/height with parcel-specific standards; TRA prohibits new residential in many areas.	Confirm whether the parcel is in an overlay and read the overlay’s written standards in the ordinance (overlay index § 28.60 and overlay sections) .
Accessory building vs. main-building rules	Accessory buildings often have different front/setback rules (e.g., 60 ft requirement); mis-applying main-building setbacks can cause noncompliance.	Use the accessory-building tables (Table 28.23C, 28.31C, 28.43C) when dimensioning garages, barns, and detached ADUs .
Height exceptions and airport/flight-obstruction areas	Height limits are subject to § 28.93 and airport restrictions (28.99); exceeding heights may require additional review.	Confirm any airport overlay, airfield clear zone, and check § 28.93 / § 28.99 for special height rules .
FAR / Lot coverage omissions	Many district tables include FAR only for specific districts (e.g., Suisun Valley). Where not listed, lot coverage may be undefined by table and governed by overlay or special plan.	If FAR or maximum coverage is not in the district table, check overlay/PP documents or contact the County — “Not found in retrieved materials” for many districts.
ADUs and state law interaction	State ADU law may limit local standards that can be applied to ADUs (e.g., minimum sizes, setbacks).	Cross-check county ADU references with current state law and the county ADU/Accessory Dwelling sections (verify with the county and see California ADU law) .

Plain-English Summary

If you own property in unincorporated Solano County, the County’s Zoning Ordinance lists the required front, side, and rear setbacks, maximum heights (commonly 35 ft), and minimum lot areas per zoning district in district-specific tables (for example Tables 28.23B, 28.22B, and 28.41B). Overlays or mapped building lines can change those numbers for a particular parcel; always check the exact district table and overlay text that apply to your parcel and the measurement rules in § 28.97 before preparing plans .

Information Gaps

County-wide, the ordinance tables frequently list setbacks and heights but do not consistently provide maximum lot coverage or floor-area-ratio for every base district (outside Suisun Valley examples). "Not found in retrieved materials" for many districts’ lot-coverage/FAR maxima — verify per parcel.
Parcel-specific building lines and mapped modifications to setbacks are referenced but the mapping data was not included in the retrieved materials — verify on the official zoning map.
County-specific ADU implementation details that reconcile local rules with the latest state ADU statutes are not fully present in the retrieved excerpts — verify with county staff and California ADU law.

Source References

Development standards and tables (Suisun Valley): § 28.23.40 and Tables 28.23B / 28.23C .
Suisun Marsh development standards: § 28.22.30 and Table 28.22B .
Commercial district development standards and Table 28.41B: § 28.41.30 / Table 28.41B .
Accessory building tables and accessory rules (examples Table 28.23C, Table 28.31C, Table 28.43C) — see those tables in the district sections (Tables cited in § 28.23, § 28.31, § 28.43) .
Setback measurement rules and allowed projections: § 28.97 (referenced throughout district tables) .
Height regulations and exceptions (airport restrictions): § 28.93 and § 28.99 references in district tables .
Parking requirements cross-reference: § 28.94 (mentioned in multiple district tables) and the county Parking page .
Overlays and policy plan overlay requirements: § 28.60 and § 28.68 (Policy Plan Overlay / overlay index) .
Travis Reserve Area Zoning Overlay text (restrictions on new residential, accessory size/height caps): overlay language in the overlay section (TRA) — see overlay text in Chapter 28 overlays .
Architectural Approval / Design Review cross-reference: § 28.102 and district references to Architectural Approval; see county Design Review page for process .
California ADU law and its interaction with local standards (for applicant reference): California ADU law and related ADU guidance (state-level) — local ADU cross-references are present in district accessory rules; verify with county staff .

Sources

Retrieved passages

Solano County Zoning Code (Section 28-99) High relevance
Solano County Zoning Code (Chapter 28) High relevance
CBC § 2 (Section 28.97) High relevance
CBC § 28.94 (Chapter 28) High relevance
Solano County Zoning Code (Chapter 28) High relevance
CBC § 28 (Chapter 28) High relevance
CBC § 3 (Chapter 28) High relevance
CBC § 66314 (§ 66314) High relevance

Cited sections

Development standards and tables (Suisun Valley): **§ 28.23.40** and Tables 28.23B / 28.23C . (§ 28.23.40)
Suisun Marsh development standards: **§ 28.22.30** and Table 28.22B . (§ 28.22.30)
Commercial district development standards and Table 28.41B: **§ 28.41.30** / Table 28.41B . (§ 28.41.30)
Accessory building tables and accessory rules (examples Table 28.23C, Table 28.31C, Table 28.43C) — see those tables in the district sections (Tables cited in **§ 28.23**, **§ 28.31**, **§ 28.43**) . (§ 28.23)
Setback measurement rules and allowed projections: **§ 28.97** (referenced throughout district tables) . (§ 28.97)
Height regulations and exceptions (airport restrictions): **§ 28.93** and **§ 28.99** references in district tables . (§ 28.93)
Parking requirements cross-reference: **§ 28.94** (mentioned in multiple district tables) and the county Parking page . (§ 28.94)
Overlays and policy plan overlay requirements: **§ 28.60** and **§ 28.68** (Policy Plan Overlay / overlay index) . (§ 28.60)
Travis Reserve Area Zoning Overlay text (restrictions on new residential, accessory size/height caps): overlay language in the overlay section (TRA) — see overlay text in Chapter 28 overlays . (Chapter 28)
Architectural Approval / Design Review cross-reference: **§ 28.102** and district references to Architectural Approval; see county Design Review page for process . (§ 28.102)
California ADU law and its interaction with local standards (for applicant reference): California ADU law and related ADU guidance (state-level) — local ADU cross-references are present in district accessory rules; verify with county staff .
SolanoCounty_ZoningCode.md

Frequently asked questions

What can I build on an R-1 or R-TC lot in unincorporated Solano County?

You must consult the specific R subdistrict table that applies (for example R-TC-D4, R-TC-MU). Typical allowed uses include single-family homes, accessory structures and accessory dwelling units (subject to ADU rules). Dimensional limits (front/side/rear yards, height 35 ft) and minimum lot area are in the district’s development table (see Table 28.32C / § 28.32.30) .

What are Solano County setback requirements?

Setbacks are set per zoning district in each district’s development table (e.g., Table 28.23B, 28.22B, 28.41B); common examples include front 30 ft (or 50 ft from centerline) in many agricultural districts, side 20 ft in ag districts, and 35 ft height caps. Always measure setbacks using the rules in § 28.97; mapped building lines can override table numbers .

How high can I build in unincorporated Solano County?

Most base districts list a 35 ft height limit in the district development tables; some commercial districts permit higher heights with a use permit (e.g., C-S up to 50 ft with a permit). Exceptions for airport flight zones and other special areas are addressed in § 28.93 and § 28.99 — verify if your parcel is within such an area .

Do accessory buildings have different setbacks?

Yes. Many agricultural and rural accessory-building tables require accessory buildings to be located 60 ft from the front property line (or on the rear 50% of the lot) and often set 20 ft side/rear accessory setbacks and 10 ft between structures; consult Table 28.23C, Table 28.31C, or Table 28.43C as applicable .

Are there floor area ratio (FAR) or lot-coverage limits?

Some districts (notably portions of the Suisun Valley tables) list FAR values (e.g., 0.5 with sewer, 0.3 without). However, FAR or lot-coverage is not consistently listed for every district. If the district table does not show a FAR/lot coverage cap, check overlays/PP plans or verify with the County. Refer to Table 28.23B for Suisun Valley examples § 28.23.40 .

Does an overlay change these standards?

Yes — Policy Plan Overlays (-PP) and other overlays (like the Travis Reserve Area) explicitly can define different setbacks, heights, coverage, and permitted uses. The overlay must be shown on the zoning map and the overlay text will enumerate its own standards; see § 28.68 and the overlay list in § 28.60 .

Do I need design review or architectural approval?

Certain uses/districts require Architectural Approval or design review; district tables refer to § 28.102 for when Architectural Approval is required (for example many Suisun Valley ATC/ATC-NC projects and Policy Plan developments) — consult § 28.102 and the county Design Review page early in your project planning .

Where are parking requirements specified?

Parking minimums are cross-referenced in the district development tables to § 28.94; Suisun Valley has special parking provisions (including parking districts) noted in district text. See Table notes in the district sections and the county Parking page .

Can I build an ADU and what setbacks apply?