Local zoning · Hercules

Hercules — Historic Preservation

Q: What triggers Historic Overlay review in Hercules?

If a parcel is designated within the H historic overlay district , any proposal that erects, relocates, alters (affecting the exterior), or demolishes a building triggers the overlay review; such work requires prior approval from the Historical Architectural Review Board (Planning Commission acting as HARB) or the City Council § 13-20.300–13-20.400 .

Q: Who decides on exterior changes to historic buildings?

The Planning Commission serves as the Historical Architectural Review Board and reviews proposed alterations, landscaping, site plans, and demolition in the H district; for major actions the City Council may also decide § 13-20.400 .

Q: What are the HTC district FAR and density limits I should design to?

The HTC Historic Town Center calls for typical new development of 1–3 stories , FAR 0.15–0.40 (typical 0.20), and residential density of up to 17 units per acre ; the detailed property rules are in Table 13‑12.2 § 13-12.100 and § 13-12.500 .

Q: Do I always need a design review for work in HTC or the H overlay?

Most new and expanded development in HTC and most exterior changes in an H district are subject to design review; small additions to single‑family homes or accessory structures may be reviewed administratively by the Community Development Director per the design review chapter — check Chapter 13‑42 for thresholds § 13-12.200 , § 13-42.200 .

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

Ask a question free See coverage

Last reviewed: July 2, 2026

Overview

This page summarizes how historic preservation is handled in the City of Hercules Zoning Ordinance (Title 13). It focuses on the local H historic overlay district, the HTC Historic Town Center district and related overlays (how they are established, what triggers review, and the design standards applicants must meet). For general zoning context see the Hercules zoning & planning overview. Design review, parking, development standards, overlays, and ADUs are referenced throughout because they materially affect projects in historic areas.

How Hercules organizes historic preservation (high level)

The City uses an H historic overlay district to identify and protect areas/buildings with unique historical character; the overlay sits on top of an underlying land‑use zone and imposes additional review and standards § 13-20.100 .
The Planning Commission acts as the Historical Architectural Review Board to review exterior changes and demolition in the H district § 13-20.400 .
The HTC Historic Town Center district is a zoning district created to preserve the historic town center character while allowing limited mixed use and controlled new development; it contains its own land‑use table and property development regulations (FAR, setbacks, density) § 13-12.100–13-12.500 .
The City maintains Historic Preservation Design Guidelines (referenced in the ordinance) that applicants must follow for exterior work § 13-20.500 . The guidelines are published by the City at the URL cited in the ordinance.

(First mention links: Hercules zoning & planning overview, design review, parking, development standards, overlay districts, ADUs, California Building Standards Code.)

H historic overlay district

Purpose

The H historic overlay district identifies areas/buildings that "possess a unique historical character" and applies an overlay review to conserve that character § 13-20.100 .

What triggers the overlay and where it applies

An H designation is established only by Council action or by owner/Planning Commission initiation and always overlays the base zoning for the same parcel(s); where overlay rules conflict, the historic overlay controls § 13-20.200 .

Review and decision-makers

Exterior alterations, relocations, new buildings or demolitions affecting buildings in an H district cannot proceed without prior approval of the City Council or the Historical Architectural Review Board (the Planning Commission acting in that role) § 13-20.300–13-20.400 .

Standards applicants must follow

The ordinance requires the City to prepare standards (the Historic Preservation Design Guidelines) covering materials, color, signs, landscaping, site development and other exterior features; applicants must submit diagrams/photos and follow those guidelines § 13-20.500–13-20.600 .

Practical takeaway

If your property is within a H overlay, expect design‑level review (HARB/Planning Commission) for almost any exterior change or demolition and plan to show how the project meets the City's Historic Preservation Design Guidelines § 13-20.300–13-20.500 .

HTC Historic Town Center (district-by-district breakdown)

Purpose

The HTC Historic Town Center district preserves the historic design and character of the Hercules Powder Company townsite while allowing compatible reuse and limited new development § 13-12.100 .

Typical permitted uses (high-level)

Mixed uses oriented to a Main Street character: retail, offices, restaurants (many uses are permitted, some require administrative or conditional permits). The full land‑use list is Table 13‑12.1 § 13-12.400 .

Key dimensional and design standards

Typical new development is 1–3 stories, FAR 0.15–0.40 (typical 0.20), and up to 17 units per acre (with limits on total units in the district) § 13-12.100 . Table 13‑12.2 sets lot sizes, front setback 10 ft, rear setback 20 ft and other property standards for HTC § 13-12.500 .

Design controls & review

All new and expanded development in HTC is subject to Chapter 13‑42 Design Review and must follow district‑specific design guidelines addressing historic styles, materials, elevations, lighting and landscaping § 13-12.200–13-12.300 .

Where it applies

The HTC district includes the City’s Historic Town Center areas (e.g., Railroad Avenue/Main Street area) as shown on the zoning maps; the ordinance ties HTC to the General Plan HTC designation § 13-12.100 .

Waterfront District Master Plan & Special overlays (how historic preservation appears)

The Waterfront District Master Plan and its subdistricts (Hercules Village, Refugio, Historic Town Center, Transit Village, Hercules Point) expressly require recognition and preservation of Hercules Powder Company townsite character; design review and adopted regulating codes apply § 13-27.100–13-27.200 .
The Special Study Area overlay district is explicitly created to cover parcels that have "historic significance and existing historic buildings" and adds additional review requirements for those parcels § 13-24.100–13-24.300 .

Quick standards & permitted-use reference table

Topic	What matters to applicants	Code Reference
H overlay purpose & overlay rule	Identifies areas of unique historic character; overlay prevails in conflicts	§ 13-20.100 and § 13-20.200
H overlay review triggers	Exterior alterations, new buildings, relocation, demolition require HARB/Council approval	§ 13-20.300–13-20.400
Historic Preservation Design Guidelines	Standards applicants must meet for materials, colors, signs, landscaping	§ 13-20.500 (guidelines URL cited)
HTC FAR & density	Typical FAR 0.15–0.40; density up to 17 du/ac; 1–3 stories	§ 13-12.100 and Table 13-12.2 § 13-12.500
Design review requirement	New/expanded development in HTC requires Design Review; review procedures are Chapter 13‑42	§ 13-12.200 and § 13-42.200
ADUs in historic contexts	ADUs are allowed; ADUs on historic contributing/landmark properties must adhere to Hercules Design Guidelines; parking waivers available in historic districts	§ 13-35.320

(See the ordinance tables for full lists of permitted uses in HTC — Table 13‑12.1 — and property development rules in Table 13‑12.2) § 13-12.400–13-12.500 .

Checklist — what an applicant must satisfy (minimum)

Confirm whether the parcel is mapped within a H historic overlay district or HTC zoning on the City zoning map; verify overlay boundaries with staff (§ 13-20.100, verify with the jurisdiction) .
Prepare and submit scaled photos, elevations, material/color samples and a site plan that show siting, screening (walls/fences), landscaping and adjacent building character as required by the H procedures § 13-20.600 .
Demonstrate conformance with the City’s Historic Preservation Design Guidelines and any district design guidelines for HTC; identify how proposed materials, massing and signage respond to those guidelines § 13-20.500 .
File for the required discretionary review: design review under Chapter 13‑42 for most exterior changes in HTC and the H overlay; expect Planning Commission review acting as HARB for significant work or demolition § 13-12.200, § 13-42.200, § 13-20.400 .
If proposing demolition or relocation of an historic structure, prepare supporting historic evaluation and be prepared for Council review/decision per § 13-20.300 .
For ADUs on historic or contributing parcels follow ADU design standards and note parking waivers in historic districts § 13-35.320 .
Coordinate any environmental/historic resources studies the City/CEQA process requires (the ordinance references architectural evaluations and Secretary of the Interior standards for major interventions) § 13-27.100 and the historic resources policies § 13-27.100 .

Risks & Ambiguities

Issue	Why it matters	What to verify
Whether a parcel is actually inside an H overlay	Overlay rules (and HARB/Council review) apply only if designated; design review and demolition controls attach	Verify current City zoning map and any recent Council ordinances; ask Community Development (Verify with the jurisdiction). § 13-20.200
Demolition of historic buildings	Demolition in an H district or of contributing structures requires prior approval and specialized review	Confirm whether project is classed as demolition under § 13-20.300 and whether Council or HARB decision is required; consider CEQA/historic resource report. § 13-20.300
Conflicts between overlay and base district standards	The overlay is written to prevail when conflicting rules exist; this can change allowable setbacks/FAR/uses	Confirm which standard is more restrictive and which controls the project; the ordinance explicitly states overlay prevails. § 13-20.200
ADU treatment on historic parcels	ADUs are allowed but the ordinance requires adherence to historic design guidelines and allows parking waivers in historic districts — local and State ADU law interact	Check ADU section § 13-35.320 for exact design/parking rules and consult Community Development about interpretation. § 13-35.320
Applicability of the City’s Historic Preservation Design Guidelines	Guidelines are required by the zoning text but are a separate published document; their status (mandatory vs. illustrative) affects review	Review the published Historic Preservation Design Guidelines (the ordinance references them) and ask whether they are adopted as mandatory standards for your permit type. § 13-20.500

Plain‑English summary

If your property is inside Hercules’s H historic overlay or the HTC Historic Town Center, expect design‑level review for exterior changes and demolition; the Planning Commission (acting as the Historical Architectural Review Board) or City Council will require that projects follow the City’s Historic Preservation Design Guidelines and district standards (FAR, setbacks, density) before construction is approved § 13-20.300, § 13-12.100–13-12.500 .

Source References

Hercules Zoning Ordinance — Chapter 13‑20, H Historic Overlay District: § 13-20.100, § 13-20.200, § 13-20.300, § 13-20.400, § 13-20.500, § 13-20.600, § 13-20.700 .
Hercules Zoning Ordinance — Chapter 13‑12, HTC Historic Town Center (purposes, performance standards, Table 13‑12.1 and Table 13‑12.2): § 13-12.100–13-12.500 .
Hercules Zoning Ordinance — Chapter 13‑27 Waterfront District Master Plan and its direction to "recognize and preserve" the Hercules Powder Company townsite: § 13-27.100–13-27.200 .
Hercules Zoning Ordinance — Chapter 13‑24 Special Study Area Overlay (historic significance called out): § 13-24.100–13-24.300 .
Hercules Zoning Ordinance — Chapter 13‑42 Design Review (who and what is subject to design review): § 13-42.200–13-42.300 .
Hercules Zoning Ordinance — Chapter 13‑35 Accessory Dwelling Units: § 13-35.320 (ADU design, parking, and historic‑property provisions) .
Historic Preservation Design Guidelines (as referenced in the ordinance): City PDF available at https://www.ci.hercules.ca.us/home/showdocument?id=198 (linked from § 13-20.500) .
For the complete code text and tables (zoning map references, district tables), see the Hercules Zoning — Title 13 Zoning Ordinance document provided (current through Ordinance 555, March 25, 2025) .

Sources

Retrieved passages

Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (Chapter 13-20.) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 2) High relevance
Hercules Zoning Code (§ 3) High relevance
Hercules Zoning Code (Chapter 13-31) High relevance
Hercules Zoning Code (Chapter 13-12) High relevance
Hercules Zoning Code (§ 2) High relevance
CBC § 21155 (Section 21155) Medium relevance
Hercules Zoning Code (Chapter 13-44.) Medium relevance
CBC § 3 (Section 66411.7) Medium relevance
CBC § 21155 (Section 21155) Medium relevance
Hercules Zoning Code (§ 2) Medium relevance
Hercules Zoning Code (Section is) Medium relevance
Hercules Zoning Code (Section cannot) Medium relevance
CBC § 2 (§ 2) Medium relevance

Cited sections

Official Hercules code library

Frequently asked questions

What triggers Historic Overlay review in Hercules?

If a parcel is designated within the H historic overlay district, any proposal that erects, relocates, alters (affecting the exterior), or demolishes a building triggers the overlay review; such work requires prior approval from the Historical Architectural Review Board (Planning Commission acting as HARB) or the City Council § 13-20.300–13-20.400 .

How is an H district established and can it be removed?

An H district is established by application (owners), Planning Commission motion or Council motion and only in conjunction with other districts; Council must make findings that the area has unique historical character and that overlay rules will preserve/enhance it § 13-20.200 . Removing the H designation requires an express application/intent — it is not automatically removed by a change in the underlying zone § 13-20.200 .

Who decides on exterior changes to historic buildings?

The Planning Commission serves as the Historical Architectural Review Board and reviews proposed alterations, landscaping, site plans, and demolition in the H district; for major actions the City Council may also decide § 13-20.400 .

Can I build an ADU on a property in a Hercules historic district?

Yes — ADUs are allowed and the local ADU rules require that ADUs located on properties designated as historic contributing or landmark adhere to the Hercules Design Guidelines for Historic Preservation; ADU parking rules also allow waivers for properties in historic districts § 13-35.320 .

What are the HTC district FAR and density limits I should design to?

The HTC Historic Town Center calls for typical new development of 1–3 stories, FAR 0.15–0.40 (typical 0.20), and residential density of up to 17 units per acre; the detailed property rules are in Table 13‑12.2 § 13-12.100 and § 13-12.500 .

Do overlay rules override the base zoning rules if they conflict?

Yes. The ordinance states that where a conflict between the historic overlay provisions and other provisions of the Zoning Ordinance occurs, the regulations in the historic overlay chapter shall prevail § 13-20.200 .

Do I always need a design review for work in HTC or the H overlay?

Most new and expanded development in HTC and most exterior changes in an H district are subject to design review; small additions to single‑family homes or accessory structures may be reviewed administratively by the Community Development Director per the design review chapter — check Chapter 13‑42 for thresholds § 13-12.200, § 13-42.200 .

What documentation does the City require when proposing designation of a new H district?

Applications to designate an H district must include scaled photos and drawings showing siting, appearance (colors/materials), landscaping/fencing, and the character of neighboring buildings; the Planning Commission holds a noticed public hearing and forwards a recommendation to Council § 13-20.600–13-20.700 .

Where are the City's Historic Preservation Design Guidelines and are they mandatory?

The Zoning Ordinance requires the City to prepare Historic Preservation Design Guidelines and references them as the standards for evaluation; the guidelines are published by the City (URL cited in the code) and are applied during review § 13-20.500 .

If my project proposes demolition, what standards/guidance apply?

Demolition of buildings in an H district or of contributing buildings is controlled; demolition generally requires prior approval (HARB or Council) and the ordinance and Waterfront policies reference preparing architectural evaluations and using the Secretary of the Interior’s Standards where appropriate § 13-20.300 and § 13-27.100 .

Ask about any Hercules property

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

Start Free Trial