Rialto — Historic Preservation

Last reviewed: July 2, 2026

Overview

Rialto’s zoning code implements historic-preservation controls primarily through the Downtown Revitalization Overlay Zone and through definitions and limited special provisions for historic structures elsewhere in Title 18 (zoning). The code requires design review and approval before demolition or exterior alteration in the downtown overlay, defines what counts as a historic structure, and offers narrow variance relief for retaining historic character in certain technical chapters; it does not contain a standalone, citywide landmark designation procedure in the retrieved materials. See the city’s rules on design review for the review pathway and overlay districts for how the downtown overlay applies.

How to read this page

Everything below is taken from the Rialto Municipal Code excerpts provided. Each substantive requirement cites the controlling code section (for example, § 18.49.030) and the uploaded ordinance file preview where that text appears. Verify parcel-specific applicability with the jurisdiction.

District-by-district breakdown

Downtown Revitalization Overlay Zone (the Downtown Overlay)

• Purpose: To implement the General Plan and Rialto Central Area Specific Plan goals, preserve and enhance scenic, historic and cultural resources of downtown, and create visual continuity and compatibility. See § 18.49.010.
• Where it applies: Properties fronting Riverside Avenue between the former Pacific Electric line and the A.T. & S.F. Railroad (specific frontage described in § 18.49.020).
• Typical permitted uses: Uses allowed by the base zone remain, but development in the overlay must satisfy the overlay’s precise plan/design approval requirements; no special “historic-only” permitted uses list is provided in the retrieved text (the overlay imposes controls on exterior changes rather than creating new use categories). See § 18.49.030 and § 18.49.040.
• Key dimensional / development standards and features:
  • Demolition, removal, or material exterior change visible from a public street or alley that would require a permit is prohibited without approval of a precise plan of design by the Community Development Director (or planning commission where applicable). See § 18.49.030(A)(1) and § 18.49.030(A)(2).
  • Property owners within the overlay have a duty to maintain structures in “good repair”; failure to maintain can be abated under Chapter 18.72. See § 18.49.030(B).
  • Unless otherwise stated, development standards in the Rialto Central Area Specific Plan apply in the overlay; the overlay also allows the Community Development Director to require setbacks as a condition of approval, but generally no required building setbacks are specified for downtown properties (see § 18.49.030(C)).
• Review triggers and decision criteria:
  • Precise plan of design approval is required before issuing building permits for exterior construction, alteration, repair, sign installations, etc., except routine maintenance. The director or planning commission considers height, bulk, materials, facades, site layout, parking, signage, lighting, landscaping and relationship to existing structures in making findings. See § 18.49.040(A)–(C) and the approval findings in § 18.65.020(E).

Rialto Central Area Specific Plan (as applied in the overlay)

• Purpose & interaction: The Central Area Specific Plan supplies the primary development standards for downtown; the overlay defers to that plan unless the overlay specifies otherwise. See § 18.49.030(C)(1).
• Practical effect: If your site is in the overlay, you must check the specific plan for dimensional standards (setbacks, lot coverage, etc.), but be prepared for overlay-specific design-review triggers and maintenance obligations. See § 18.49.030(C).

Other zoning chapters that affect historic resources (definitions, flood-variance protection)

• Definition of historic structure: Title 18 defines “historic structure” by reference to National Register listings, contributing properties to registered historic districts, state inventories, or local inventories recognized by the Secretary of the Interior. See § 18.75.050 (definition text is provided there).
• Variances for historic structures: The floodplain chapter allows variances for repair/rehabilitation of “historic structures” where the work will not preclude continued historic designation and the variance is the minimum necessary to preserve historic character. See § 18.75.270(B). This is a narrow technical variance connected to floodplain management, not a general planning exemption.
• Two-unit / ADU eligibility limitation tied to historic status: The two-unit project chapter contains an explicit restriction that a lot “must not be a historic property or within a historic district included on the State Historic Resources Inventory” and “nor may the lot be … designated by ordinance as a city or county landmark or as a historic property or district” for certain ministerial two-unit approvals. See § 18.113.050(D). This is a local prohibition on using that specific two-unit pathway on recognized historic properties.

Decision‑relevant standards and triggers — quick table

Practical guidance / synthesis

• If your property lies in downtown (check § 18.49.020 for frontage limits), treat almost any exterior change as trigger for the overlay’s precise plan of design and design review; demolition is discouraged and requires a finding of non-significance by the director before a demolition permit will be issued. See § 18.49.020 and § 18.49.030(A).
• The code treats the historic-protection function largely as design-review control (preventing detrimental exterior changes) and as a maintenance obligation (keep buildings in good repair). It does not, in the retrieved text, set up a distinct local landmark designation board or an extensive local historic register process. Not found in retrieved materials: a citywide ordinance describing local landmark nomination and designation procedures. Verify with the city.
• When a resource is formally listed on national, state, or a certified local inventory, it qualifies as a historic structure under the code definition; that definition carries special treatment in limited contexts (for example, floodplain variances). See § 18.75.050 and § 18.75.270(B).
• State ADU law allows ADUs on historic properties subject to objective standards that prevent adverse impacts on historically-listed resources; the Rialto two-unit chapter specifically excludes some ministerial two-unit approvals where the lot is historic (see § 18.113.050(D)). For ADU-specific standards in Rialto, consult the city’s ADU ordinance and the state rules; see the city ADU page and the California Building Standards Code for building-code compliance. Link: ADUs and California Building Standards Code.
• Expect mandatory coordination: if your downtown project includes new signage, lighting, or parking changes you must satisfy overlay design-review criteria that explicitly list these items among the review factors. See § 18.49.040(B)(7)-(9).

Checklist

• Confirm whether the property is within the Downtown Revitalization Overlay Zone (Riverside Ave frontage limits) — see § 18.49.020.
• Determine whether the building is a historic structure under § 18.75.050 (National Register, state inventory, or certified local inventory).
• If in the overlay or altering a structure visible from the street, prepare and submit a precise plan of design application to the Community Development Department; include elevations, materials, colors, signage and site layout. See § 18.49.040 and § 18.65.020.
• If demolition is proposed, obtain a director finding that the structure is not a significant architectural or historical asset or work through the planning commission appeal process. See § 18.49.030(A)(2).
• If the work affects a property listed as historic and you need technical relief (for example, flood-elevation related), prepare variance justification showing minimum necessary impact per § 18.75.270(B).
• For any alterations, be ready to satisfy review factors: height, bulk, materials, facades, parking, signage, lighting, landscaping and neighbor impacts. See § 18.49.040(B) and § 18.65.020(E).
• If pursuing ADUs or two-unit options, verify whether the project is excluded by § 18.113.050(D) (historic-lot exclusion) and consult the city ADU rules and state ADU guidance. Link: Rialto ADUs and California ADU law.

Risks & Ambiguities

Plain-English Summary

If your property is within Rialto’s downtown overlay, you cannot demolish or materially change the street-facing exterior without plan approval; the city uses precise design-review rules to protect downtown’s historic and visual character, and a defined “historic structure” gets limited protections in other technical chapters—check whether your lot is listed or in an overlay before starting work. See § 18.49.030, § 18.49.040, and § 18.75.050.

Source References

• Downtown Revitalization Overlay Zone (purpose and application): § 18.49.010–§ 18.49.020.
• Overlay development standards; demolition/alteration prohibition; duty to maintain: § 18.49.030.
• Design review triggers and review criteria for the overlay: § 18.49.040 and precise-plan contents § 18.65.020.
• Definition of “historic structure”: § 18.75.050.
• Variance allowance for repair/rehabilitation of historic structures (flood chapter): § 18.75.270(B).
• Two-unit project exclusions for historic lots: § 18.113.050(D).
• ADU/state guidance (context on ADU & historic resources): 2025 California ADU handbook (provided file).

Retrieved passages

• Rialto Zoning Code (Chapter 18.113) High relevance show source text
• Rialto Zoning Code (chapter is) Medium relevance show source text
• Rialto Zoning Code (Title XII) Medium relevance show source text
• Rialto Zoning Code (§ 2) Medium relevance show source text
• Rialto Zoning Code (§ 1) Medium relevance show source text
• CBC § 65913.4 (Section 65913.4) Medium relevance show source text
• Rialto Zoning Code (Section 18.49.040.) Medium relevance show source text
• Rialto Zoning Code (§ 1) Medium relevance show source text

Cited sections

• Downtown Revitalization Overlay Zone (purpose and application): **§ 18.49.010–§ 18.49.020**. (§ 18.49.010)
• Overlay development standards; demolition/alteration prohibition; duty to maintain: **§ 18.49.030**. (§ 18.49.030)
• Design review triggers and review criteria for the overlay: **§ 18.49.040** and precise-plan contents **§ 18.65.020**. (§ 18.49.040)
• Definition of “historic structure”: **§ 18.75.050**. (§ 18.75.050)
• Variance allowance for repair/rehabilitation of historic structures (flood chapter): **§ 18.75.270(B)**. (§ 18.75.270)
• Two-unit project exclusions for historic lots: **§ 18.113.050(D)**. (§ 18.113.050)
• ADU/state guidance (context on ADU & historic resources): 2025 California ADU handbook (provided file).
• Rialto_ZoningCode.md
• 2025 California ADU handbook.md

• Official Rialto code library