Local zoning · Loomis

Loomis — Overlay Districts

Q: Do HUD/state ADU rules override local overlays when building an ADU?

Local ADU rules are in § 13.42.270 , but ADU approvals must also comply with state ADU law. Where there is tension between local overlay rules and state ADU minimums, state ADU law and state guidance limit what local overlays may require; for parcel‑specific questions verify with planning staff. See § 13.42.270 .

Overlay Districts under the Loomis local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

Loomis’ zoning ordinance (Title 13) recognizes the concept of overlay or combining controls, but the code as codified in the retrieved Title 13 materials does not publish a separate list of named "overlay districts" in Division 2. Instead, the ordinance implements site- or parcel‑specific modifications through numeric suffixes to base zones (for example, RS‑suffixes and RH‑20), and through the planned development (PD) district and project-level tools. See the zoning map and district list at § 13.20.020 for how districts are established.

(If you are looking for an overlay map or an “overlay” label on a parcel, verify with the town — the zoning map on file with the department is the controlling authority.)

How Loomis handles "overlay" effects (short)

The zoning map establishes base districts (Table 2‑1) and any modifiers are applied as suffixes or special district ordinances rather than a separately‑titled overlay chapter in the materials retrieved here. See § 13.20.020 and Table 2‑1.
Numeric suffixes (for RS/RM) and special variants such as RH‑20 are the mechanism the code uses to indicate parcel‑level variations in density/standards. See § 13.24.050 (RS & RM numeric suffixes and density tables).
The Planned Development (PD) district provides a formal mechanism to alter uses and standards for a specified area via ordinance and an approved plan. See § 13.29.010 and the PD approval/findings at § 13.29.030 and § 13.29.040.

District-by-district breakdown (overlay-relevant entries)

Note: this section focuses on the districts and mechanisms the Loomis code uses to achieve “overlay”-type results (suffixes, PD, project-level master plans). For any named overlay district (for example a "historic overlay" mapped across parcels) the retrieved files did not show a separate overlay map or a named overlay chapter — Not found in retrieved materials. Verify with the Town for map-level overlays.

RS (Single-Family Residential) — including RS‑10 / RS‑20 suffixes

Purpose: Applied to single‑family neighborhoods; RS‑5 is used downtown; numeric suffixes set parcel-specific density/lot size rules. See § 13.24.020 and the RS/RM density tables.
Typical permitted uses: single‑family homes, accessory residential uses (including accessory dwelling units subject to the ADU rules). See residential uses tables and accessory unit section § 13.42.270.
Key dimensional standards (examples): RS‑20 = 20,000 sf minimum lot area; RS‑10 = 10,000 sf; maximum coverage and setbacks vary by suffix; see Table 2‑5 / § 13.24.050 for the full matrix.
Where it applies: mapped on the official zoning map; numeric suffix shown on the zoning map and implemented through Table 2‑5. See § 13.20.020 and § 13.24.050.

RM / RH (Medium / High Density Residential) and RH‑20

Purpose: RM for medium density multifamily; RH for higher density; RH‑20 is a specific variant requiring a minimum of 20 units/acre and allows up to 25 units/acre “by right” to facilitate affordable housing objectives. See § 13.24.010 through § 13.24.050 and the RH‑20 description.
Typical permitted uses: multifamily (duplex, townhome, apartment), mixed‑use where allowed in commercial districts per the map. See the residential and mixed‑use tables.
Key dimensional standards: RM/RH density and lot-size rules are set in Table 2‑4/2‑5 and described in § 13.24.040 / § 13.24.050 (referenced in the code). RH‑20 specific purpose and flexibility is stated in the RH‑20 text.
Where it applies: parcels designated on the zoning map with the RM/RH symbol (suffixes shown where applicable). See § 13.20.020.

PD (Planned Development) — mechanism for site‑specific modifications

Purpose: PD allows combining uses and modifying development standards for a clearly defined site where a higher level of design and flexibility is appropriate. See § 13.29.010 through § 13.29.050.
Typical permitted uses: any use compatible with the general plan and neighborhood as authorized by the PD ordinance (PD identifies allowed uses and standards). See § 13.29.030.
Key dimensional / process points: PD is adopted via ordinance (PD + ordinance number placed on the map); PD establishment requires preliminary and specific development plans and findings (see § 13.29.030 and § 13.29.040).
Where it applies: PD districts are mapped on the zoning map (symbol “PD” + ordinance number) and applied only by council action. See § 13.29.030 and mapping rules in § 13.20.020.

Master Development Plan (project-level overlay control)

A master development plan is required where the applicable zoning district or the nature of the site calls for a coordinated review (sensitive sites, multi‑use projects). The requirements and decision findings are in § 13.62.070. A master plan can function like an overlay by prescribing land uses and standards across multiple parcels subject to the plan.

"Overlay districts" as a separate named category

Not found in retrieved materials: The retrieved Title 13 files do not present a separate, enumerated list of named overlay districts (for example, "Historic Overlay" or "Scenic Corridor Overlay") in Division 2. The code does define the notion that a primary zoning district can be combined with another zoning control (see the code’s approach to suffixes and PD districts), but a mapped, labeled overlay list is not present in the materials we searched. Verify with the Town of Loomis for any map layers or overlay ordinances not included in the retrieved files.

Quick decision‑relevant table (selected items)

Overlay/Modifier	When used / purpose	Most decision‑relevant standards	Code Reference
Numeric zone suffixes (e.g., RS‑20, RS‑10)	Parcel‑specific density/lot area adjustments for RS / RM zones	Minimum lot area, permitted density, coverage and setbacks per Table 2‑5	§ 13.24.050
RH‑20	Incentivize higher density (20–25 u/ac) to aid housing goals	Minimum 20 units/acre; alternative standards may be applied to meet affordable housing	§ 13.24.050 (RH‑20 text)
PD (Planned Development)	Site‑specific flexibility to change uses/standards when superior design is delivered	PD adopted by ordinance; requires preliminary & specific development plans; required findings in PD rules	§ 13.29.010, § 13.29.030, § 13.29.040
Master Development Plan	When district or project complexity calls for coordinated review	Master plan required findings and council approval process	§ 13.62.070
Named overlay districts (e.g., “historic” overlay)	—	Not listed in retrieved Division 2 materials — verify with Town	Not found in retrieved materials; see zoning map § 13.20.020

Practical guidance & interpretation (plain language)

If your parcel shows a suffix (for example RS‑20 or RH‑20) on the zoning map, treat that suffix as the operative “overlay/modifier” — the numeric suffix controls density/lot rules for that parcel (see § 13.24.050).
If you seek departures from base-zone standards across a multi‑parcel site (re‑mixing uses, modifying setbacks, clustering), a PD or master development plan is the normal path in Loomis (see § 13.29.010 and § 13.62.070).
Always check the official zoning map on file at the department — the ordinance incorporates the map by reference and the director is authorized to resolve boundary questions. See § 13.20.020.

Links you may need while reading this page: the town’s main zoning overview is at the Loomis Zoning page, and related procedural or technical rules live under Development Standards, Parking, Design Review, ADUs, and Historic Preservation. Also remember building rules are in Title 24 (California Building Standards). (These terms are linked where first mentioned on this page to the Loomis menu.)

Loomis Zoning (/us/california/loomis/zoning) — first mention is linked.
Loomis Development Standards (/us/california/loomis/development-standards) — first mention linked.
Loomis Parking (/us/california/loomis/parking) — first mention linked.
Loomis Design Review (/us/california/loomis/design-review) — first mention linked.
Loomis ADUs (/us/california/loomis/adu) — first mention linked.
Loomis Historic Preservation (/us/california/loomis/historic-preservation) — first mention linked.
California Building Standards Code (/us/california/building-codes) — first mention linked.

(These are internal menu links embedded in the prose above.)

Checklist (what an applicant proposing “overlay‑like” changes must satisfy)

Confirm the parcel’s base zoning and any numeric suffix on the official zoning map; use § 13.20.020 as the starting point.
Determine whether the change can be handled ministerially (zoning clearance) or requires a discretionary approval (minor use permit/use permit/PD/master plan). See § 13.22.020 (general development requirements) and the permit matrices in Division 2.
If proposing a PD or master plan, prepare preliminary and specific development plans and satisfy the PD findings in § 13.29.030 / § 13.29.040 and master development plan findings in § 13.62.070.
Prepare site plans addressing development standards (setbacks, height, coverage) in Division 3 and the district tables (e.g., Table 2‑5 for RS/RM). See § 13.30.010 and Table 2‑5/§ 13.24.050.
Account for design review where required (e.g., second-story additions, commercial façade or master plans) and follow the Design Review chapter/procedures. See design review references and § 13.62.040 (design review cross‑references).
For housing projects consider RH‑20 provisions and residential incentives (density bonuses); see § 13.24.025 and RH‑20 text.
Verify off‑street parking and loading requirements when intensifying use — see the Parking chapter and Table 3‑9 / Table 3‑11.

Risks & Ambiguities

Issue	Why it matters	What to verify
No named overlay list found in Division 2	Applicants may assume a “historic” or other overlay applies when it is not mapped in Title 13	Check the official zoning map on file with the department and ask planning staff; confirm there is no separate overlay ordinance. See § 13.20.020.
Interpretation of numeric suffixes (e.g., RS‑20)	Suffixes change density, lot area and sometimes setbacks — misreading leads to wrong entitlement path	Confirm which table (Table 2‑5 / § 13.24.050) controls your parcel’s standards and verify the suffix shown on the map.
Parcel split by district boundary	Boundary uncertainty can change allowable uses and required approvals	Boundary disputes are resolved by director using map scale rules in § 13.20.020(B) — verify with the director and request an official boundary interpretation.
Whether PD / master plan is needed	PD/master plan triggers discretionary review and additional findings	Confirm project scope vs. PD triggers and see PD criteria in § 13.29.010 and master plan rules § 13.62.070.
ADU rules and overlay interaction	State ADU law can preempt certain local restrictions; overlay modifications might not override state ADU rules	Follow local ADU section § 13.42.270 and check state ADU law; confirm which standards are ministerial vs. discretionary.

Plain‑English Summary

Loomis’ Title 13 treats overlays indirectly: rather than a separate, named overlay chapter, the town uses zone suffixes (like RS‑20, RH‑20), Planned Development districts (PD), and project‑level master plans to change standards for particular parcels or large sites. If your parcel shows a suffix or PD on the official zoning map, that symbol — and the tables/PD ordinance — control your project’s rules; for everything else, check the official zoning map and talk to planning staff to confirm whether an overlay exists for your parcel. See § 13.20.020, § 13.24.050, and § 13.29.010 for the controlling rules.

Source References

§ 13.20.020 (Zoning map and zoning districts) — establishes districts and map incorporation; use the official zoning map on file.
§ 13.24.050 / Table 2‑5 (RS & RM density, suffixes and development standards) — numeric suffix approach (RS‑10, RS‑20, etc.).
§ 13.29.010 — Purpose of Planned Development (PD) district; § 13.29.030 / § 13.29.040 — PD procedures and findings.
§ 13.22.020 (General requirements for development and new land uses) — baseline permit rules and requirement to obtain land use permits.
§ 13.62.070 (Master development plan applicability and findings).
§ 13.42.270 (Accessory dwelling unit—local ADU rules).
§ 13.36.110 and Table 3‑9 / Table 3‑11 (Parking and loading requirements) — parking and loading standards to check when intensifying use.

If you want the official map check or a parcel‑specific determination, ask the Town of Loomis planning department for the current zoning map extract and any ordinance adopting PD or other parcel‑specific modifications (PD ordinance numbers are recorded on the map). See the zoning map rules in § 13.20.020.

Sources

Retrieved passages

Loomis Zoning Code (section shall) Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code (Section 13.42.260) Medium relevance
Loomis Zoning Code (Title 13) Medium relevance
Loomis Zoning Code (title eliminates) Medium relevance
Loomis Zoning Code Medium relevance
Loomis Zoning Code (Section 13.42.260) Medium relevance
Loomis Zoning Code (title to) Medium relevance
Loomis Zoning Code (title or) Medium relevance
Loomis Zoning Code Medium relevance
Loomis Zoning Code (Title 13.) Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code (chapter to) Medium relevance
CBC § 13.22.040 (§ 13.22.040.) Medium relevance
Loomis Zoning Code (title as) Medium relevance
Loomis Zoning Code (title for) Medium relevance
Loomis Zoning Code (title references) Medium relevance
CMC § 471 Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code (§ 13.70.020.) Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code (§ 1) Medium relevance
Loomis Zoning Code Medium relevance
Loomis Zoning Code (§ 13.36.110.) Medium relevance

Cited sections

Official Loomis code library

Frequently asked questions

What exactly is an overlay district in Loomis?

Loomis’ adopted Title 13 recognizes the concept of applying an additional control to a parcel, but the retrieved code does not list separate, named overlay districts in Division 2. Instead, the town commonly uses numeric zone suffixes (e.g., RS‑20, RH‑20), Planned Development (PD) ordinances, and master development plans to accomplish overlay‑like changes. Confirm with the official zoning map at the planning department. See § 13.20.020 and § 13.24.050.

If my parcel is “RS‑20,” what does that mean for allowed uses and setbacks?

An RS‑20 suffix indicates the RS single‑family zoning with the RS‑20 density/lot area standard (generally 20,000 sf minimum lot area). The full lot‑size, setback, height, and coverage rules are in Table 2‑5 and the residential district text; check § 13.24.050 and the related tables.

Are there any named overlays (historic, scenic, etc.) mapped in Loomis Title 13?

Not found in the retrieved Title 13 materials — the Division 2 tables and map text we reviewed do not show a standalone list of named overlays. Verify with the town’s planning department or the official zoning map on file. See § 13.20.020.

Can a Planned Development (PD) act as an overlay?

Yes. A PD ordinance is a formal way to change allowed uses and development standards for a mapped area; it is adopted by ordinance and tied to the map (PD + ordinance number), and the PD approval process and required findings are in § 13.29.010 and § 13.29.030 / § 13.29.040.

Do HUD/state ADU rules override local overlays when building an ADU?

Local ADU rules are in § 13.42.270, but ADU approvals must also comply with state ADU law. Where there is tension between local overlay rules and state ADU minimums, state ADU law and state guidance limit what local overlays may require; for parcel‑specific questions verify with planning staff. See § 13.42.270.

If a parcel is split by a zone boundary which rules apply?

The director resolves zoning map boundary uncertainty using the map scale and the rules in § 13.20.020(B). Always request an official interpretation from the director for parcel‑specific situations.

Do I automatically need a design review for overlay‑type changes?

Design review requirements depend on the type of work and district; many accessory retail and site changes require design review. Check the specific use standards and the design review procedures referenced in Division 4 and § 13.42.030 (cross‑reference to § 13.62.040). If a PD or master plan is required, design criteria are integral to those reviews.

How can I find whether a PD ordinance or other parcel‑specific ordinance applies to my lot?

The zoning map is annotated with PD district symbols and ordinance numbers; the code incorporates the map by reference at § 13.20.020 — request a certified zoning map extract or a staff check at the Planning Department for the official record.

Can a master development plan modify parking or loading standards for a site?

Yes — master plans and PDs can prescribe or condition site layout, parking and loading consistent with findings required by § 13.62.070, but any modification must still comply with applicable code provisions unless the PD/master plan explicitly modifies those standards and the approving authority makes the required findings. See § 13.62.070 and the parking chapter (Table 3‑9 / Table 3‑11).

Who interprets overlay or mapped boundary questions?

The planning director has authority to interpret provisions of Title 13, including map boundary questions, per § 13.10.050 and the zoning map interpretation rules in § 13.20.020(B). For formal disputes, the matter can be referred to the commission.

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