Colusa — Historic Preservation

Last reviewed: July 1, 2026

Overview

Colusa’s Landmark and Historic Preservation rules live in Article 30 — Landmark and Historic Preservation of the City Zoning Code (commonly Title 17). The article establishes a Heritage Preservation Commission (HPC) process for designating landmarks, historic districts, and historic resources, and it requires HPC review for most exterior changes, demolition, and some construction affecting designated properties. This page summarizes what the ordinance requires, how it intersects with Colusa’s zoning districts and development standards, and the practical steps applicants must follow. See the citywide context at Colusa zoning & planning overview (/us/california/colusa) and the base Colusa Zoning rules that the preservation article supplements.

Article 30 key controls and authorities (grounding):

• Designation of landmarks and historic districts and required contents of a designating ordinance: § 30.04.
• Permit/review requirement for exterior work or construction on designated properties: § 30.05 (HPC approval required).
• Demolition/removal review and required findings to allow demolition: § 30.06.
• Criteria for designation (landmark / district / resource): § 30.07.
• Applicability, enforcement, and duty to maintain designated resources: § 30.08.
• Appeals to the city council and timelines: § 30.09.

How Article 30 sits inside Colusa’s districts and standards

Article 30 applies across the City’s zoning map and interacts with the specific district regulations in Title 17. The code’s list of general zoning districts is found at § 2.01; see the full district list there. Where a landmark or historic district exists, the designating ordinance may add controls that override or supplement the base district rules (for example, façade, setback or height controls).

Below is a district-by-district breakdown (purpose, typical permitted uses, key dimensional rules where the ordinance provides them, and how historic-preservation rules typically apply). Where the local district article supplies numbers I cite them; where not present in the retrieved material I note that the code text for that district’s dimensional table was Not found in retrieved materials and you should Verify with the jurisdiction.

R-1 (Single-Family Residence District)

• Purpose: Intended for single-family residential development. § 5.01.
• Typical permitted uses: one-family dwellings, accessory buildings, small residential care facilities, public parks/schools and secondary dwelling units (ADUs) (subject to ADU standards). § 5.02. Link to ADU guidance at Colusa ADUs (/us/california/colusa/adu).
• Key dimensional standards: The article sets generic application rules; explicit numeric setbacks/coverage for R-1 are not quoted in the retrieved excerpts. Not found in retrieved materials — Verify with the jurisdiction and with Colusa Development Standards (/us/california/colusa/development-standards).
• Historic-preservation impact: If an R-1 parcel becomes a designated landmark or part of a historic district, HPC approval is required for exterior alterations and for construction that affects the exterior; routine maintenance is allowed but owners must keep exteriors in good repair. § 30.05(c), § 30.08(c).

R-2 (Two-Family Residence District)

• Purpose & permitted uses: Multi-family/adaptive two-unit residential uses consistent with Article 6 (R-2) standards. See § 6.xx for details (not fully quoted in retrieved snippets). Not found in retrieved materials for full numeric table — Verify with the jurisdiction.
• Historic-preservation impact: Same HPC jurisdiction and permit rules apply if a property is designated. § 30.05.

R-3 / R-4 (Neighborhood Apartment / General Apartment Districts)

• Purpose: Intended for multifamily dwellings and higher density housing. § 8.01 (R-3/R-4).
• Typical uses: Multifamily units, accessory parking, supportive housing types; R-4 explicitly permits uses allowed in R-1–R-3 plus multifamily. § 8.02.
• Key dimensional standards (examples found in code): R-3 Front Yard Setback: 20 ft; Side yard interior: minimum 5 ft on one side; total both sides need not exceed 15 ft; Building height limit: up to 4 stories / 50 ft (R-3/R-4 examples). § 8.05. Link to Development Standards at Colusa Development Standards (/us/california/colusa/development-standards).
• Historic-preservation impact: HPC review required for exterior changes to designated multiunit structures; rehabilitation proposals must satisfy Secretary of the Interior standards where referenced. § 30.05(f)(3).

C-N, C-G (Neighborhood and General Commercial)

• Purpose: C-N serves neighborhood convenience retail; C-G provides general commercial services; both allow some civic uses. § 9.01, § 10.01.
• Typical uses: Retail, restaurants, professional offices, public buildings; C-N explicitly incorporates many retail and service uses. § 9.02.
• Dimensional standards (examples): C-N front yard setback: 15 ft; rear yard: 15 ft; building height limit: 1 story / 30 ft (where stated in the article). § 9.03.
• Historic-preservation impact: Designation can impose additional façade, setback, and height controls for a historic district; HPC approvals govern exterior changes to landmarks in commercial zones. § 30.04(c)(2), § 30.05. Link to Colusa Design Review (/us/california/colusa/design-review).

C-H / M-1 / M-2 / M-L (Highway Service & Industrial Districts)

• Purpose & typical uses: Industrial and highway-service activities; M-L is “Limited Manufacturing” (research, light manufacture, offices). § 14.01–14.03 (M‑L).
• Dimensional example for M-L: Lot area: 10,000 sq ft; Front/Side/Rear setbacks: 20 ft; Building height limit: 2 stories / 35 ft. § 14.04.
• Historic-preservation impact: Industrial-era buildings may qualify as landmarks/resources; HPC review covers exterior alterations and demolition. § 30.07, § 30.05, § 30.06.

P-D / P-F (Planned Development / Public Facilities)

• Purpose: P‑D for planned multi-use developments with site-specific regulations; P‑F for public facilities, parks, schools and “historical sites and monuments.” § 15.01–15.03, § 16.01. P‑F explicitly lists historical sites and monuments as principal permitted uses. Link to Overlay Districts (/us/california/colusa/overlay-districts) when discussing special controls.
• Historic-preservation impact: Publicly owned landmarks may be subject to interior architectural review under the designating ordinance. § 30.04(c)(1).

O-S, F-W, M-U-* (Open Space, Floodway, Mixed-Use Districts)

• Purpose & uses: Open space/floodway protect natural features and limit development; several mixed-use districts (Bridge St, Downtown, Main St, Residential Mixed Use) are in the district list § 2.01. § 2.01.
• Historic-preservation impact: Historic districts may overlay downtown/mixed-use areas and the designating ordinance may add façade/setback/height rules. § 30.04(c)(2).

Note: The zoning articles above provide the baseline permitted uses and selected dimensional rules; Article 30 sits on top of these rules for designated properties. For any parcel-specific dimensional question, Verify with the jurisdiction and the planning department. Not all numeric setbacks or lot coverage figures were present in the retrieved snippets for every district.

Most decision‑relevant standards and permits (quick table)

Checklist

• Confirm whether the property is on the City historic resources inventory or is a designated landmark/historic district (Planning Department checklist). § 30.03, § 30.04(c).
• If modifying a designated property, prepare and file detailed exterior plans with the Planning Department (materials, colors, elevations, and environs relationship). § 30.05(c).
• For demolition/removal: expect HPC review, provide alternatives analysis and evidence re: economic feasibility and safety (per demolition findings). § 30.06(f).
• If proposing a new historic-district designation, obtain owner consents as required (historic-district applications require 100% owner consent). § 30.04(e)(2).
• Anticipate timeframes: HPC decision within 60 days of a complete application; possible temporary 180‑day suspension on permit action in preservation situations. § 30.05(d)–(e).
• If rehabilitation raises building‑code conflicts, examine the California Historical Building Code and SHBC options; coordinate with Building Official. Link to California Building Standards Code (/us/california/building-codes).

Risks & Ambiguities

Plain‑English summary

If your Colusa property is listed as a landmark or lies inside a historic district, you must get Heritage Preservation Commission approval before making exterior changes or demolishing buildings; the HPC applies preservation criteria, can delay action to find preservation solutions, and the city may require owners to maintain designated buildings. § 30.05, § 30.06, § 30.08.

Source References

• City of Colusa, Title 17 — Zoning: Article 30, Landmark and Historic Preservation, § 30.01–30.09 (purposes, definitions, designation, permits, demolition, enforcement, appeals). See § 30.01, § 30.03, § 30.04, § 30.05, § 30.06, § 30.07, § 30.08, § 30.09.
• City of Colusa, Title 17 — Zoning: District list and district articles (R‑1 through Mixed‑Use), § 2.01 and applicable district articles (R‑1: § 5.01–5.03; R‑3/R‑4: § 8.01–8.05; C‑N: § 9.01–9.03; M‑L: § 14.01–14.04; P‑D/P‑F: § 15.01–15.03, § 16.01).
• Secretary of the Interior’s Standards referenced in Colusa code (used as review standard): § 30.05(f)(3).

Where the retrieved municipal excerpts did not include a numeric rule or table for a given district, the entry above states “Not found in retrieved materials” and you should Verify with the City Planning Department or consult the full Title 17 on the City/MuniCode site.

Retrieved passages

• Colusa Zoning Code High relevance show source text
• Colusa Zoning Code (article and) High relevance show source text
• Colusa Zoning Code (article and) High relevance show source text
• Colusa Zoning Code (article 36) High relevance show source text
• Colusa Zoning Code (article and) Medium relevance show source text
• CBC § 18950 (article IX) Medium relevance show source text
• CBC § 30.05 (article and) Medium relevance show source text
• CBC § 30.05 (section and) Medium relevance show source text
• Colusa Zoning Code (Section 32.01.) Medium relevance show source text
• Colusa Zoning Code (Article 2.) Medium relevance show source text
• CBC § 8 (chapter is) Medium relevance show source text
• CBC § 8 (SECTION 8-1001) Medium relevance show source text
• California Building Code (Article 35.) Medium relevance show source text
• Colusa Zoning Code (§ 26) Medium relevance show source text
• Colusa Zoning Code (article shall) Medium relevance show source text

Cited sections

• City of Colusa, Title 17 — Zoning: Article 30, Landmark and Historic Preservation, **§ 30.01–30.09** (purposes, definitions, designation, permits, demolition, enforcement, appeals). **See** **§ 30.01**, **§ 30.03**, **§ 30.04**, **§ 30.05**, **§ 30.06**, **§ 30.07**, **§ 30.08**, **§ 30.09**. (Title 17)
• City of Colusa, Title 17 — Zoning: District list and district articles (R‑1 through Mixed‑Use), **§ 2.01** and applicable district articles (R‑1: **§ 5.01–5.03**; R‑3/R‑4: **§ 8.01–8.05**; C‑N: **§ 9.01–9.03**; M‑L: **§ 14.01–14.04**; P‑D/P‑F: **§ 15.01–15.03**, **§ 16.01**). (Title 17)
• Secretary of the Interior’s Standards referenced in Colusa code (used as review standard): **§ 30.05(f)(3)**. (§ 30.05)
• Colusa_ZoningCode.md

• Official Colusa code library