Local zoning · Clayton

Clayton — Historic Preservation

Q: Can I place a manufactured home on a parcel that is on the California Register?

No. Manufactured homes and mobile homes on a permanent foundation are prohibited from being located on real property that is listed in the California Register of Historic Places § 17.36.078.C .

Historic Preservation under the Clayton local zoning and planning code, with the controlling citations.

Ask a question free See coverage

Last reviewed: July 1, 2026

Overview

Clayton's Title 17 Zoning contains limited, topic-specific rules that affect historic resources through the Resource Overlay (RD), site-/development-plan review standards, ADU rules that treat historic districts specially, and a manufactured-home prohibition on properties listed in the California Register. This page summarizes what the Clayton zoning ordinance itself requires for preservation, where those rules sit in the code, and what applicants should check before proposing changes that could affect a historic structure or district.

What the code actually says (high‑level)

The Resource Overlay (RD) expressly includes preservation of historic sites and structures among its purposes and requires an approved RD Development Plan for projects in the overlay § 17.34.010—§ 17.34.050 .
Site plan and development review must consider compatibility with existing architectural and historical character as part of the Standards of Review § 17.44.040 .
The ADU rules include a specific carve‑out for historic properties: ADU design and parking rules treat properties in an “architecturally and historically significant historic district” differently and cross‑reference an internal subsection for preservation standards § 17.47.060 (and Subsection 17.47.060A.3) .
Manufactured and mobile homes on permanent foundations are prohibited on parcels listed in the California Register of Historic Places § 17.36.078.C .

Note: This page stays strictly within the zoning/Title 17 rules. For building‑code or accessibility relief for historic structures see the California Building Standards Code.

How districts / zones handle historic resources — district‑by‑district

Below are the Clayton districts most relevant to historic preservation. Each subsection lists the ordinance purpose language, typical permitted uses or limits relevant to preservation, and the key dimensional / review standards that influence preservation outcomes.

Resource Overlay (RD)

Purpose: To preserve natural topography and to "maintain development and use for historic sites and structures that preserve the character of historic sites and adjacent area" § 17.34.010 .
Where it applies: The RD overlay is applied to base districts by adding the RD designator on the zoning map; an RD Plan is required for all development § 17.34.020—§ 17.34.050 .
Typical effect on projects: Projects in RD must submit a Resource Development Plan and supporting reports (topography, tree inventory, soils, geology, landscape) and the Planning Commission approves the RD plan (appealable to City Council) § 17.34.060—§ 17.34.070 .
Practical guidance: If your property is in RD, expect an RD plan and studies and a Planning Commission hearing; preservation of historic features is an explicit purpose to be addressed in submittals § 17.34.060 .

Single‑Family Residential districts (R‑10, R‑12, R‑15, R‑20, R‑40, R‑40‑H)

Purpose / permitted uses: Typical single‑family uses and accessory structures; ADU rules allow additional units subject to Chapter 17.47 § 17.16.010—§ 17.16.020 .
Key dimensional standards: Front/exterior/side/rear setbacks and minimum lot sizes are specified across Sections 17.16.030—17.16.120; ADU-specific setback table references these districts (e.g., R‑10 / R‑12 / R‑15 front setback 20 ft) § 17.47.060C .
Historic relevance: ADU standards require matching exterior materials and roof slope to the primary dwelling and include an explicit ADU exception for properties in an "architecturally and historically significant historic district" (parking exception) § 17.47.060H / 17.47.060G.2.b .

Multiple‑Family Residential districts (M‑R, M‑R‑M, M‑R‑H)

Purpose / permitted uses: Duplexes, townhomes, apartments and accessory uses; ADUs allowed per Chapter 17.47 where zone allows multifamily § 17.20.010—§ 17.20.030 .
Historic relevance: Converted ADUs within existing multifamily structures are explicitly permitted (converted garage/attic/basement) and must comply with state building standards; conversions affecting historically significant multifamily buildings should be reviewed under site plan / design standards § 17.47.030A.3 .

Public Facility (PF)

Purpose: Public uses including museums and libraries; PF sites may have special development review and are subject to site plan review where historic resources are often located § 17.33.010—§ 17.33.030 .
Historic relevance: Projects reusing PF properties will be evaluated with site plan / development standards that require sensitivity to historical features (see Site Plan Review Standards) § 17.44.040 .

Other zones / regulatory tools that affect preservation

Site Plan Review (all districts) — New development meeting thresholds requires a Site Plan Review Permit; the Standards of Review explicitly call out conformity with city‑adopted architectural/design standards and compatibility with adjacent structures and views § 17.44.020—§ 17.44.040 .
Planned Development / Development Plan — Larger or PD projects must include community facilities plans and identify "significant historical, cultural and archaeological features" and propose how they will be preserved § 17.28.090—§ 17.28.160 .
ADU rules and historic resources — ADU technical standards (setbacks, FAR, lot coverage, parking) are set in § 17.47.060; Subsection 17.47.060A.3 contains the special ministerial preservation provisions referencing the Secretary of the Interior's Standards for Treatment of Historic Properties for qualifying cases § 17.47.060 & § 17.47.060A.3 .
Manufactured homes — Manufactured/mobile homes on a permanent foundation are prohibited on parcels listed in the California Register § 17.36.078.C .

Decision‑relevant standards and examples (table)

Topic	Rule / Practical effect	Code reference
RD overlay purpose; requirement for plan	RD explicitly includes preserving historic sites; RD Development Plan required before grading, subdivision or similar approvals	§ 17.34.010—§ 17.34.050
Site plan review standards	Planning review must consider compatibility with existing architectural/historical character, views, materials and scale	§ 17.44.040
ADU parking exception for historic districts	ADU parking requirement may be waived when the ADU is located within an "architecturally and historically significant historic district"	§ 17.47.060G.2.b
ADU preservation standard (ministerial)	ADU work affecting historic resources must "Comply with objective ministerial standards" aligned with the Secretary of the Interior's Standards (see Subsection)	§ 17.47.060A.3
Manufactured homes on historic parcels	Prohibited on parcels listed in the California Register of Historic Places	§ 17.36.078.C
Community development submittal requirement	Development plan applications must show location of significant historic/cultural/archaeological features and methods for preservation	§ 17.28.090 (Community Facilities Plan items)

How historic rules interact with other topics (first mention links)

ADU rules in § 17.47.060 can waive parking requirements for properties in historic districts; check the ADU chapter before designing parking layouts parking § 17.47.060G.2.b .
Setbacks and other development standards still apply to ADUs unless specifically modified; ADU setbacks reference the single‑family district table (for example R‑10 / R‑12 / R‑15 front setback 20 ft) development standards § 17.47.060C .
Historic‑resource sensitivity is considered within standard design review and Site Plan Review factors; expect review under those procedures for visible alterations design review § 17.44.040 .
If a property sits in an overlay, the overlay rules apply in addition to base zoning — e.g., the RD overlay requires an RD Plan and additional submittals overlays § 17.34.020—§ 17.34.060 .
When preparing ADU applications on historic properties, follow Chapter 17.47, and consult the local ADU rules and state ADU law; see the city's ADU page for process steps ADUs § 17.47.005—§ 17.47.080 .
For building‑code relief or technical standards that sometimes apply to historic buildings, consult the state code California Building Standards Code.

Checklist — what an applicant must satisfy (quick‑start)

Confirm whether the parcel is inside the RD overlay or a designated local historic district (check zoning map and overlay layers). Verify with the jurisdiction. § 17.34.020 .
If in RD, prepare and submit an RD Development Plan with required maps/reports (topo, tree inventory, soils, geology, hydrology, landscape) § 17.34.060 .
For any project triggering Site Plan Review (size/height thresholds), prepare materials demonstrating compatibility with historical character per the Standards of Review § 17.44.020—§ 17.44.040 .
If proposing an ADU on or affecting a historic resource, follow Chapter 17.47: meet the objective ministerial preservation standards (Secretary standards where required), ADU setbacks and architectural matching, and confirm parking treatment (possible waiver for historic districts) § 17.47.050—§ 17.47.070 .
Do not propose a manufactured home on a parcel listed in the California Register — those are expressly prohibited § 17.36.078.C .
For Development Plan / Planned Development submittals include the Community Facilities Plan itemizing historical/cultural/archaeological features and preservation methods § 17.28.090 .
Expect discretionary approvals (Planning Commission / City Council appeals) where RD, PD, or Use/Development Plans are required; follow noticing and public comment requirements § 17.34.050; § 17.60.030 .

Risks & Ambiguities

Issue	Why it matters	What to verify
"Architecturally and historically significant historic district" — what is it?	The ADU parking exception and some ministerial preservation standards hinge on this phrase and whether a parcel qualifies § 17.47.060G.2.b / 17.47.060A.3 .	Verify whether Clayton has an adopted local historic district map or register; Not found in retrieved materials — Verify with the jurisdiction.
Which municipal subsection contains Secretary of the Interior compliance?	The ADU chapter cross‑references a ministerial standard tied to the Secretary of the Interior's Standards (limiting what conditions the City may impose) § 17.47.060A.3 .	Confirm with Community Development which forms and checklists implement Subsection 17.47.060A.3; request written guidance or objective standards from staff.
Is a proposed alteration subject to Site Plan Review or only building permits?	Site Plan Review thresholds (size/height) can convert what would be ministerial into discretionary review, which affects timeline and public notice § 17.44.020—§ 17.44.030 .	Confirm whether the proposed work triggers Site Plan Review criteria (height >16 ft, area >750 sq ft, etc.).
Local listing vs. California Register	Some code provisions reference "California Register" and others reference local significance; state vs local listing can change applicability (e.g., manufactured homes) § 17.36.078.C .	Verify whether the parcel is on the California Register or on any local register/list. Not found in retrieved materials: official lists or maps.
Objective vs. subjective design review standards	State ADU law limits subjective standards; Clayton's ADU chapter invokes objective ministerial standards for historic treatment — but implementation detail matters § 17.47.060A.3 .	Ask staff for the city's objective preservation checklist that implements Subsection 17.47.060A.3.

Plain‑English summary

Clayton's zoning code does not run a full local "historic preservation ordinance" in Title 17, but it uses the Resource Overlay (RD), site/development plan standards, and specific ADU rules to protect historic character: expect extra design scrutiny, special submittal requirements if you are in the RD overlay or a designated historic place, and an ADU path that requires objective preservation standards tied to the Secretary of the Interior's treatment standards § 17.34.010; § 17.44.040; § 17.47.060A.3 .

Source References

Resource Overlay (RD) purpose and requirements — § 17.34.010—§ 17.34.060
RD Development Plan submittal items — § 17.34.060—§ 17.34.070
Site Plan Review triggers and Standards of Review — § 17.44.020—§ 17.44.040
Planned Development / Development Plan requirements, including community facilities plan and historic features — § 17.28.090; § 17.28.160—§ 17.28.170
ADU chapter (definitions, standards, parking exceptions, preservation standard reference) — § 17.47.005; § 17.47.030; § 17.47.050; § 17.47.060; § 17.47.070; § 17.47.080; Subsection 17.47.060A.3
Manufactured/mobile homes prohibition on parcels listed in the California Register — § 17.36.078.C
Zoning map / district designators and single‑family district standards (R‑10…R‑40‑H) — § 17.08.020; § 17.16.010—§ 17.16.120

Sources

Retrieved passages

CFC § 17.33.010 (Section 17.33.010) Medium relevance
Clayton Zoning Code (Chapter 17.47) Medium relevance
Clayton Zoning Code (Chapter 17.34) Medium relevance
Clayton Zoning Code (section may) Medium relevance
Clayton Zoning Code (chapter as) Medium relevance
Clayton Zoning Code (§ 65915) Medium relevance
Clayton Zoning Code (§ 17.47.010) Medium relevance
Clayton Zoning Code (Chapter 17.38) Medium relevance
Clayton Zoning Code (Section 17.28.170) Medium relevance
Clayton Zoning Code (Title 16) Medium relevance
Clayton Zoning Code (Chapter 15.70) Medium relevance
Clayton Zoning Code (Title 17) Medium relevance
CPC § 66000 (Section 17.47.030) Medium relevance
Clayton Zoning Code (§ 66314) Medium relevance
Clayton Zoning Code (Chapter 17.80) Medium relevance
CFC § 17958.1 (section if) Medium relevance
Clayton Zoning Code (§ 65852.3) Medium relevance

Cited sections

Official Clayton code library

Frequently asked questions

What does the Resource Overlay (RD) require for historic properties in Clayton?

If a property is in the RD overlay, the project must submit and obtain approval of an RD Development Plan before grading, subdivision, or comparable approvals; the RD’s purposes explicitly include preserving historic sites and structures § 17.34.010—§ 17.34.050 .

Do I need to do anything special for an ADU on a historically significant property?

Yes. Clayton’s ADU rules require ADUs that affect historic resources to meet the ordinance’s objective ministerial preservation standards (cross‑referenced to the Secretary of the Interior’s Standards) and provide exemptions for parking when the ADU is within an "architecturally and historically significant historic district" § 17.47.060A.3; § 17.47.060G.2.b .

Where in the Clayton code is compatibility with historic character considered?

Compatibility and preservation of architectural/historical character are explicit factors in the Site Plan Review Standards (Standards of Review) that the Planning Commission uses when evaluating projects § 17.44.040 .

Can I place a manufactured home on a parcel that is on the California Register?

No. Manufactured homes and mobile homes on a permanent foundation are prohibited from being located on real property that is listed in the California Register of Historic Places § 17.36.078.C .

What paperwork will a development plan need to show regarding historic features?

A Development Plan / Planned Development submittal must include a Community Facilities Plan that lists the location of significant historical, cultural and archaeological features and methods proposed to preserve/integrate those elements § 17.28.090 (Community Facilities Plan items) .

Does being in a historic district automatically exempt me from parking requirements for an ADU?

The ADU chapter provides a parking exception where an ADU is located within an "architecturally and historically significant historic district" — that exception applies to the ADU off‑street parking requirement § 17.47.060G.2.b . You must confirm whether your property is in such a district (Not found in retrieved materials — Verify with the jurisdiction).

When will a project be subject to Site Plan Review (and therefore historical compatibility review)?

Site Plan Review is required for development meeting thresholds such as construction over 16 ft in height, area over 750 sq ft, or other criteria listed in § 17.44.020; those triggers bring the project under the Standards of Review § 17.44.020—§ 17.44.040 .

Where does Clayton say to follow the Secretary of the Interior's Standards?

Clayton’s ADU chapter references compliance with objective ministerial standards for preservation, rehabilitation, restoration, or reconstruction that align with the Secretary of the Interior's Standards for applicable situations; this language appears in Subsection 17.47.060A.3 of the ADU chapter § 17.47.060A.3 .

If my project is visible from the street, does the code treat it differently for historic resources?

Yes — the ordinance language tied to the ADU historic‑resource subsection includes an explicit consideration of visibility from a public right‑of‑way (the rule lists that qualifying work may need to "be located so as to not be visible from any public right‑of‑way") § 17.47.060A.3 .

How do I find whether my house is in a Clayton historic district or on a local list?

Clayton’s zoning code references historic district concepts but does not include an embedded local historic‑district map or local listing index in Title 17. The code requires verification with the zoning map/overlay and with Community Development; the ordinance language that applies to overlays is § 17.34.020 and the official zoning map is adopted under § 17.08.020 — contact the City for the authoritative map (Not found in retrieved materials) § 17.34.020; § 17.08.020 .

Ask about any Clayton property

Get a cited, plain-English answer on Clayton zoning, setbacks, FAR, ADUs and permits — for any address.

Start Free Trial