Walnut — Land Use

Last reviewed: July 3, 2026

Overview

This page summarizes what the City of Walnut's zoning ordinance actually says about land use: which uses are permitted or conditional, how the city organizes districts (residential, commercial, industrial, overlay), and the most decision‑relevant development controls (setbacks, lot coverage, density rules where the code states them). For a first read use the Walnut zoning & planning overview to orient to maps and permits; then use the specific district citations below to check whether a proposed use is outright permitted or requires a Conditional Use Permit or site review.

Notes on navigation in this page: when you see bold district names that’s the code’s label (for example R-1, C-1, MU/HOO-1). If you need the city’s published numeric development standards (setbacks, lot coverage, parking ratios) consult the Walnut Development Standards page; if the parcel is in an overlay, consult the Walnut Overlay Districts page. This page stays strictly on land‑use outcomes in the ordinance (what uses are allowed and where); building code, permitting procedures, and tenant law live elsewhere.

How Walnut organizes uses (short primer)

• The ordinance lists permitted uses in each base zone and then lists additional conditional uses that may be allowed with a Conditional Use Permit (CUP) (see § 6.64.030 for the CUP framework) .
• When a parcel is inside a Mixed‑Use / Housing Opportunity Overlay (MU/HOO) the overlay appends new permitted uses and density ranges to the underlying zone — the overlay does not remove conditional uses that are allowed in the base zone (see § 6.20.020 – § 6.20.040) .
• Parking requirements are frequently referenced to Chapter 6.68 (off‑street parking) and must be checked for the specific use; see Walnut’s parking guidance on the Walnut Parking page.

District-by-district breakdown (purpose, typical permitted uses, key dimensional controls, where it applies)

R-1 (One‑Family Residential)

• Purpose: One‑family detached residential living. Permitted uses focus on single‑family dwelling and limited accessory/agricultural activities. Permitted uses: one‑family dwelling, agricultural crops, limited grazing (with acreage limits), parks/trails, family day care — see § 6.12.020.
• Accessory uses: accessory buildings, guesthouses/second units (subject to separate rules), home occupations — see § 6.12.030.
• Key dimensional standards (examples): front/side/rear yard rules and minimum lot area/width are in the R‑1 chapter; the ordinance gives graduated front‑yard depths by dwelling size and minimum lot widths by lot area. See the R‑1 yard/table language in the R‑1 provisions. Always verify with the parcel‑specific lot size.

R-2 (Limited Multiple‑Family Residential)

• Purpose: Small multi‑family developments on relatively larger lots; permits limited multi‑family units. Permitted uses: any R‑1 use plus two or more family dwelling units (§ 6.28.020) .
• Dimensional highlights: minimum lot area 8,000 sq ft, minimum lot width 75 ft, front yard 20 ft, side yards 5 ft (corner lot street side 10 ft), rear yard 20 ft, maximum lot coverage 50% (§ 6.28.040–6.28.080) .
• Where it applies: R‑2 is described in Chapter 6.28 of the code.

R-3 (Multiple‑Family Residential)

• Purpose: Apartment and other multiple‑family housing. Permitted uses: multiple dwelling units/apartment houses (and certain conditional institutional uses) — see § 6.32.020.
• Dimensional standards: maximum lot coverage 60%; parking and signage controlled by Chapters 6.68 and 6.92 respectively; other yard/access rules spelled out in Chapter 6.32.

R-4 (Medium‑High Residential, form‑based)

• Purpose: Medium‑high density residential under a form‑based code adopted by reference; allowed uses are tightly limited and tied to the adopted form‑based standards. Permitted: Townhomes, Condominiums, Senior housing, Residential developments with 20% lower income units, Parking structures — see § 6.34.020.
• Controls: The chapter includes a land‑use table and specific development standards (density 32–36 du/ac, lot sizes, setbacks, story/height caps) in § 6.34.040.

R-5 (High Residential)

• Purpose: Higher density residential (form‑based code applied by reference). Permitted (limited list): Townhomes, Condominiums, Senior housing, Projects with 20% lower income units, Parking structures — see § 6.35.020.

RPD (Residential Planned Development)

• Purpose: Planned residential developments with flexible site design; standards (open space, coverage, parking) are specific to the RPD chapter and tied to CUP/PD approval. Lot coverage, open space, and parking requirements (e.g., 40% maximum building coverage, minimum 20% open space) are spelled out in the RPD chapter.

C-1 (Light Commercial)

• Purpose: Neighborhood retail and limited commercial/residential. Permitted uses include bakeries, banks, barber shops, clinics, single‑family dwelling, offices, retail stores, restaurants (no drive‑ins), etc. See § 6.40.020 for the enumerated list.
• Conditional uses (CUP required) include gas stations, bars, hospitals, parking lots as a commercial business, private clubs, schools, etc. See § 6.40.030.
• Development standards: minimum lot area 7,200 sq ft, height limit 2 stories or 35 ft, front yard 20 ft, max lot coverage 50%, off‑street parking per Chapter 6.68 — see § 6.40.060–§ 6.40.080.

C-3 (Heavy Commercial)

• Purpose: Broader commercial uses that serve community/regional retail and services. Permitted uses are broad (indoor auction, automobile rental, athletic fields, etc.) but open storage/accessory outdoor uses are typically restricted or require CUP — see § 6.44.020.
• Controls: front yard 15 ft, side/rear buffers when adjoining residential, height 2 stories or 35 ft, max lot coverage 50%, and off‑street parking per Chapter 6.68 (§ 6.44.070–6.44.080)

C‑P (Commercial‑Professional)

• Purpose: Professional and limited commercial uses with development standards to protect adjacent residential areas. Permitted uses and controls are listed in Chapter 6.36 (look there for the detailed use list and yard/parking rules).

M‑1 (Light Manufacturing / Industrial)

• Purpose: Integrated light manufacturing and compatible industrial/commercial uses. Permitted: some agricultural/open uses (golf, parks) and many enclosed light industrial activities; most outside storage/display requires a CUP. See § 6.48.010–6.48.020 for the full permitted list and the policy that emergency shelters are allowed as of right in M‑1 pursuant to State law references.

Mixed‑Use / Housing Opportunity Overlay (MU/HOO — MU/HOO‑1, MU/HOO‑2, MU/HOO‑3)

• Purpose: Provide additional development options and incentives (density bonus, relaxed standards) to meet housing goals and integrate commercial and multifamily development. The overlay is appended to the base zoning and creates allowed higher density residential uses subject to a specific plan in many cases. See § 6.20.010–§ 6.20.070.
• Highlights: MU/HOO‑1 allows underlying C‑1/C‑3 uses plus multifamily on lots ≥1 acre with densities 12–36 du/ac when a specific plan applies; MU/HOO‑2 builds off C‑3 and sets minimum commercial acreage and density ranges 12–28 du/ac (subject to a specific plan); MU/HOO‑3 is a mixed set of areas mapped to R‑1, R‑3, or retail uses with specific minimum lot sizes or densities depending on the MU area — see § 6.20.030–§ 6.20.060.

School & Public Institution Zone

• Purpose: For schools and public institutions; when allowed they have site plan and architectural review by the Planning Commission, strict setback rules (e.g., 20 ft from public right‑of‑way, 10 ft interior, very large buffers required for parking adjoining residential) and height caps (generally 3 stories / 35 ft) — see § 6.50.060.

Quick reference table — selected permitted uses and code citations

ADUs (Accessory Dwelling Units) — where the ordinance stands on land‑use

Walnut has a comprehensive ADU/JADU section in the zoning code that (1) permits certain ADUs by building permit if they meet objective criteria, (2) requires ADU permits for others, and (3) sets side/rear setback minima of 4 ft, FAR/lot‑coverage caps tied to base zones (e.g., R‑1 max 40% lot coverage, R‑2 50%, R‑3 60%), and (4) includes specific size/height/parking and fire‑safety cross‑references. These ADU rules and the ADU approval pathways are present in the code excerpts we retrieved but the exact top‑level section number heading for the ADU chapter was not located in the retrieved files; the text fragments, including the 4‑ft setbacks and lot‑coverage caps, appear in the ADU development standards subsections in the zoning code text available in the files. See the ADU approval descriptions and development standards in the zoning code excerpts.

• Building code: ADUs must comply with local building code requirements; see the California Building Standards Code for state building requirements referenced in the ADU rules.

Note: Because the ADU material in the retrieved files appears as subsections but did not include a clear top‑level § number in the excerpts available to us, treat the above as a summary of the ordinance language found in the retrieved materials. For parcel‑level application of ADU rules verify the specific ADU subsection and the City’s ADU permit flowchart with the Community Development Department and the city’s ADU guidance page Walnut ADUs.

Information Gaps (what I could not confirm in the retrieved materials)

• Exact parcel-to-zone mapping (which parcels are MU/HOO‑1/2/3, specific lot lines) — Verify with the city's official zoning map. (Not found in retrieved materials.)
• Complete, use‑by‑use parking rates are referenced to Chapter 6.68 but the full parking tables per use are not included in the excerpts I reviewed — check Chapter 6.68 and Walnut Parking. (Partial reference only.)
• The ADU content was clearly present but the top‑level section number for the ADU chapter was not visible in the retrieved snippets — confirm the governing section number on the city site if you need an exact § citation for permitting paperwork. (Top‑level § not found in retrieved materials.)
• Design review objective standards and the complete checklist are referenced (site plan & architectural review in Chapter 6.84) but the full Chapter 6.84 text was not included in the snippets — consult Walnut Design Review and Chapter 6.84.

Checklist (what an applicant must satisfy to confirm a proposed land use)

• Confirm base zone for the parcel and read the base zone permitted uses (e.g., R-1 § 6.12.020, C-1 § 6.40.020).
• If in an overlay (e.g., MU/HOO), read the overlay permitted uses/density incentives and confirm whether a specific plan applies (§ 6.20.020–§ 6.20.070) and whether the overlay adds allowed residential uses.
• If a use is not listed, check § 6.50.050 (uses not listed are prohibited unless Planning Commission finds a similar use acceptable).
• If the use is conditional, prepare a CUP application per § 6.64.040 (findings required, notice, public hearing).
• Verify required parking amount and layout per Chapter 6.68 (referenced in each zone chapter). See the Walnut Parking page for guidance.
• Confirm setbacks, lot coverage, FAR and height limits in the applicable zone chapter (e.g., C‑1 yard rules § 6.40.070; R‑3 lot coverage § 6.32.070).
• If in MU/HOO, confirm whether the project will be processed under a specific plan and whether density bonuses/relaxed standards are available (see § 6.20.050–§ 6.20.060).
• For ADUs: confirm whether the proposed ADU qualifies for Building Permit‑only approval or needs an ADU permit, and verify 4 ft side/rear setbacks and lot coverage caps by base zone in the ADU subsections. If building permit‑only, ADU still must meet fire/safety and building code requirements. See the city ADU rules and Walnut ADUs.

Risks & Ambiguities

Plain‑English summary

Walnut’s zoning code lists specific allowed uses for each zone (for example R‑1 is for one‑family homes, C‑1 for neighborhood retail, M‑1 for light manufacturing) and makes other uses possible only through Conditional Use Permits; the Mixed‑Use/Housing Opportunity Overlay adds higher‑density residential and incentives on top of base zones. Always check the specific zone chapter for permitted/conditional lists and the overlay language for density incentives — start with the district § citations below and confirm parking and ADU rules before filing.

Source References

• Walnut Municipal Code — R‑1 permitted & accessory uses, § 6.12.020–6.12.030.
• Walnut Municipal Code — R‑1 yard table and dimensional rules (R‑1 yards/frontages) — (R‑1 yard text) (see R‑1 chapter excerpts).
• Walnut Municipal Code — R‑2 chapter: § 6.28.020–6.28.080 (uses, lot size, yards, lot coverage).
• Walnut Municipal Code — R‑3 chapter: permitted uses and lot coverage § 6.32.020, § 6.32.070.
• Walnut Municipal Code — R‑4 chapter (form‑based): § 6.34.020–6.34.040 (permitted uses and development standards).
• Walnut Municipal Code — C‑1 chapter (uses, conditional uses, yards, parking): § 6.40.020–6.40.080.
• Walnut Municipal Code — C‑3 chapter (uses; yards; parking): § 6.44.020–6.44.080.
• Walnut Municipal Code — M‑1 chapter (light manufacturing uses): § 6.48.010–6.48.020.
• Walnut Municipal Code — Mixed‑Use/Housing Opportunity Overlay: § 6.20.010–§ 6.20.070 (uses, incentives, standards of review).
• Walnut Municipal Code — Conditional Use Permit procedures and findings: § 6.64.020–§ 6.64.040.
• Walnut Municipal Code — ADU permit/approval pathways and development standards (setbacks, lot coverage caps by zone) — ADU subsections in the zoning text excerpts (ADU approvals, 4‑ft setbacks, lot coverage caps by zone). Top‑level ADU § number not located in retrieved snippets; verify the official ADU § number in the city code.

Retrieved passages

• Walnut Zoning Code (§ 6.20.040.) High relevance show source text
• Walnut Zoning Code (§ 6.20.040.) High relevance show source text
• Walnut Zoning Code (§ 6.40.020.) High relevance show source text
• Walnut Zoning Code (§ 6.12.020.) High relevance show source text
• Walnut Zoning Code (§ 6.48.020.) High relevance show source text
• Walnut Zoning Code (Chapter 2-5) High relevance show source text
• Walnut Zoning Code (§ 6.40.030.) High relevance show source text
• Walnut Zoning Code (§ 6.64.020.) High relevance show source text
• Walnut Zoning Code (§ 6.40.060.) Medium relevance show source text
• CFC § 150 Medium relevance show source text
• CBC § 310 (section may) Medium relevance show source text
• Walnut Zoning Code (§ 6.20.020.) Medium relevance show source text

Cited sections

• Walnut Municipal Code — R‑1 permitted & accessory uses, **§ 6.12.020–6.12.030**. (§ 6.12.020)
• Walnut Municipal Code — R‑1 yard table and dimensional rules (R‑1 yards/frontages) — (R‑1 yard text) **(see R‑1 chapter excerpts)**. (chapter excerpts)
• Walnut Municipal Code — R‑2 chapter: **§ 6.28.020–6.28.080** (uses, lot size, yards, lot coverage). (§ 6.28.020)
• Walnut Municipal Code — R‑3 chapter: permitted uses and lot coverage **§ 6.32.020, § 6.32.070**. (§ 6.32.020)
• Walnut Municipal Code — R‑4 chapter (form‑based): **§ 6.34.020–6.34.040** (permitted uses and development standards). (§ 6.34.020)
• Walnut Municipal Code — C‑1 chapter (uses, conditional uses, yards, parking): **§ 6.40.020–6.40.080**. (§ 6.40.020)
• Walnut Municipal Code — C‑3 chapter (uses; yards; parking): **§ 6.44.020–6.44.080**. (§ 6.44.020)
• Walnut Municipal Code — M‑1 chapter (light manufacturing uses): **§ 6.48.010–6.48.020**. (§ 6.48.010)
• Walnut Municipal Code — Mixed‑Use/Housing Opportunity Overlay: **§ 6.20.010–§ 6.20.070** (uses, incentives, standards of review). (§ 6.20.010)
• Walnut Municipal Code — Conditional Use Permit procedures and findings: **§ 6.64.020–§ 6.64.040**. (§ 6.64.020)
• Walnut Municipal Code — ADU permit/approval pathways and development standards (setbacks, lot coverage caps by zone) — ADU subsections in the zoning text excerpts (ADU approvals, **4‑ft setbacks**, lot coverage caps by zone). Top‑level ADU § number not located in retrieved snippets; verify the official ADU § number in the city code. (§ number)
• Walnut_ZoningCode.md

• Official Walnut code library