Local zoning · Tiburon

Tiburon — Overlay Districts

Q: What overlay zones exist in Tiburon and where are they described?

Tiburon’s ordinance lists the F (Flood Hazard) , RMP/AHO (Residential Multiple Planned/Affordable Housing Overlay) , NC/AHO (Neighborhood Commercial/Affordable Housing Overlay) , and HPO (Historic Protection Overlay) . The overlay rules and purposes are codified under § 16-23.010–.060 of the Zoning Ordinance.

Q: What do the Affordable Housing Overlays require to get incentives?

To qualify for RMP/AHO or NC/AHO incentives you must meet the overlay’s affordability qualifications (including the required percentages of very-low, low, and moderate units, deed‑restriction terms, and any special‑needs set‑asides) and follow the development standards in Table 2‑4. See § 16-23.030(D) and § 16-23.040–.050 .

Q: What review is required for changes to a building in the Historic Protection Overlay?

Exterior alterations to buildings in the HPO generally require the Director’s approval of a Site Plan and Architectural Review application for Minor Alterations, and projects are reviewed for consistency with the Downtown Tiburon Design Handbook and the Local Historic Inventory; see § 16-23.060(B–C) .

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

Ask a question free See coverage

Last reviewed: July 2, 2026

Overview

Tiburon’s overlay zones are special-purpose layers that sit on top of the base zoning map and modify permitted uses, development standards, and review rules for parcels where town policy or hazard-management goals apply. The overlay system in the Town’s Zoning Ordinance is established to implement flood-safety, affordable-housing objectives, and downtown historic preservation goals, among other policy aims; the controlling provisions are codified in Title IV, Chapter 16 of the Tiburon Municipal Code (the Zoning Ordinance) under § 16-23.010 et seq.

Before you design a project, confirm whether an overlay appears on a property on the Town’s adopted Zoning Map and Planned Development Map; overlays are mapped and described in § 16-14.020 and applied by reference in the ordinance.

What the code establishes (district-by-district)

Below are the overlay districts actually named in the Tiburon Zoning Ordinance, what they do, the most decision-relevant rules, and where they typically apply.

Flood Hazard Overlay — F

Purpose and where mapped: The F (Flood Hazard Overlay) limits and controls construction in identified flood-prone areas and is intended to implement federal flood-insurance program requirements; the ordinance ties the overlay boundaries to the Town’s floodplain maps and delegates administration to the Town Engineer. See § 16-23.020(A) for purpose and mapping direction (the provision also points you to Municipal Code Chapter 13D for technical flood rules).
Typical permit/standards trigger: Projects in the F zone are regulated by the Flood Damage Prevention chapter; the overlay requires compliance with flood elevation and construction rules adopted elsewhere in Town code (Municipal Code Chapter 13D). Verify base flood elevations from the current FEMA Flood Insurance Rate Maps as incorporated into the code. Verify with the jurisdiction for parcel-specific base flood elevation and any required floodproofing.

Residential Multiple Planned / Affordable Housing Overlay — RMP/AHO

Purpose: The RMP/AHO overlay encourages substantial affordable housing production on sites the General Plan Housing Element identifies as opportunity sites and provides development incentives in return for deed-restricted housing. See § 16-23.020(B).
Typical permitted uses: Residential uses (multifamily, two-family, single-family) are allowed but qualification rules apply to get the overlay incentives; see § 16-23.030(A) for permitted uses and qualification rules in § 16-23.030(D). The ordinance requires deed restrictions and minimum affordable percentages for projects claiming the AHO benefits.
Key dimensional / development standards: Development must conform to the Overlay Zones development standards in Table 2‑4; the ordinance lists height and density ranges and delegates some standards to review processes (Site Plan and Architectural Review). Notable standards in Table 2‑4 include a maximum of 3 stories or 38 ft. (whichever is less) and a density range of 12.4–24.8 units per acre for qualifying RMP/AHO projects (final lot coverage and setback details are determined through the required review). See § 16-23.040 and Table 2‑4.
Incentives and conditions: The RMP/AHO offers density/flexibility, parking reductions, fee waivers or reductions, priority processing, and design flexibility for affordable units; however projects must meet the overlay’s affordability mix (for example, certain minimum percentages of very-low, low, and moderate units and deed restriction terms) to qualify — see § 16-23.030(D) and § 16-23.050(A). The overlay’s incentives are distinct from State density bonus provisions and have special interaction rules; see § 16-23.030(E) and § 16-70.110.

Neighborhood Commercial / Affordable Housing Overlay — NC/AHO

Purpose: The NC/AHO overlay is similar to the RMP/AHO but applied to certain commercial parcels to facilitate mixed-use development with an affordable housing component. See § 16-23.020(C).
Typical permitted uses: Allowed residential uses (multifamily, two-family) are listed in § 16-23.030(B); the NC/AHO does not prohibit the underlying commercial uses and is intended to encourage mixed-use outcomes.
Key dimensional / development standards and incentives: Table 2‑4 sets the NC/AHO density range at 12.9–20.7 units per acre (with development standards determined through Conditional Use Permit and/or Site Plan and Architectural Review). Parking may be shared between commercial and residential uses where reasonable; the Review Authority can reduce parking requirements depending on the project and on-street parking availability. See § 16-23.040 and § 16-23.050(B).

Historic Protection Overlay — HPO

Purpose and where mapped: The HPO (Historic Protection Overlay) protects and enhances buildings listed on the Town’s Local Historic Inventory of Buildings Located in Downtown Tiburon; the HPO is specifically focused on Downtown Tiburon. See § 16-23.020(D).
Permitted uses: The HPO does not create a new use list — uses permitted are the same as the underlying NC and VC commercial zones — but any exterior change is subject to enhanced review. See § 16-23.060(A).
Controls and review: Exterior alterations to buildings in the HPO generally require the Director’s approval of a Site Plan and Architectural Review application for Minor Alterations (or other review based on scope). The review is guided by the Downtown Tiburon Design Handbook and the Local Historic Inventory; the ordinance emphasizes retention of historic fabric, matching replacement features, and using the State Historic Building Code where applicable. Key requirements are in § 16-23.060(B–C).

Decision-relevant table (quick reference)

Overlay Zone	Most decision-relevant standards or incentives	Typical permit / review required	Code Reference
F (Flood Hazard Overlay)	Floodplain construction standards; regulated elevations per FEMA maps; Town Engineer as floodplain administrator	Compliance with Municipal Code Chapter 13D; potential flood-elevation documentation	§ 16-23.020(A)
RMP/AHO	3 stories or 38 ft. max height; density 12.4–24.8 units/acre; incentives (density, parking relaxations, fee waivers); deed‑restriction requirements for affordability	Site Plan & Architectural Review and conditional approvals as required to secure incentives; review authority determines lot coverage and setbacks	§ 16-23.040, § 16-23.050, § 16-23.030(D)
NC/AHO	Density 12.9–20.7 units/acre; parking may be shared or reduced; retains underlying commercial uses	Conditional Use Permit and/or Site Plan & Architectural Review; review for mixed‑use compatibility	§ 16-23.030(B), § 16-23.050(B)
HPO	Historic-preservation review standards; Downtown Tiburon Design Handbook applies; repainting exceptions for Benjamin Moore Historical Colors	Director approval of Site Plan & Architectural Review (Minor Alterations) for exterior changes; possible use of California State Historic Building Code	§ 16-23.060(B–C)

Practical guidance and synthesis (plain-English interpretation)

Confirm overlays early: Always check the Town’s adopted Zoning Map / Planned Development Map to see if F, RMP/AHO, NC/AHO, or HPO applies to your parcel (adopted via § 16-14.020). If an overlay applies, the overlay’s rules supplement and sometimes supersede the underlying zone’s rules. Verify with the jurisdiction for parcel-specific mapping and interpretation.
Affordable‑housing overlays are incentive-driven, not automatic: To get the RMP/AHO or NC/AHO benefits (density, parking relief, fee waivers), a project must meet the overlay’s qualification rules, including required affordable-unit mixes and deed restrictions (see § 16-23.030(D)). If you don’t meet those requirements you do not automatically receive the incentives.
Downtown historic overlay imposes design controls, not new uses: If your property is in the HPO, the use list comes from the underlying commercial zone, but exterior changes are subject to stricter design rules and review intended to preserve historic character; the Downtown Tiburon Design Handbook is explicitly listed as a review guidance document in § 16-23.060.
Flood overlay requires coordinated technical documentation: Projects in the F zone must follow the Town’s Flood Damage Prevention chapter and current FEMA maps; the Town Engineer is the floodplain administrator (see § 16-23.020(A)).
Review authority flexibility: Many overlay standards (lot coverage, setbacks, parking) are determined through the Review Authority using Site Plan & Architectural Review or Conditional Use Permit processes; the ordinance expects case‑by‑case design tradeoffs — consult staff early. See the general overlay purpose and review language in § 16-23.010 and the development standards in § 16-23.040–.050.

Note: Site-level dimensional rules (setbacks, lot coverage, parking counts) referenced here are implemented in the ordinance’s General Development Standards; see the Town’s development standards for details on setbacks and parking. For parking rules see the Town’s parking standards and the ordinance’s Article III references. Hyperlinked resources (below) will take you to those topic pages.

First-time mentions of related topics (internal links):
- For base zoning and map confirmation: see Tiburon Zoning. (Tiburon Zoning)
- For development specifics like setbacks and standards: see Tiburon Development Standards. (Tiburon Development Standards)
- For design review requirements and processes: see Tiburon Design Review. (Tiburon Design Review)
- For parking reductions and shared parking rules mentioned in AHO incentives: see Tiburon Parking. (Tiburon Parking)
- For projects involving historic buildings: see Tiburon Historic Preservation. (Tiburon Historic Preservation)
- For accessory or secondary dwelling questions that are regulated elsewhere in the code: see Tiburon ADUs. (Tiburon ADUs)
- When work triggers building-code compliance: see California Building Standards Code. (California Building Standards Code)

Checklist (what an applicant must satisfy when an overlay applies)

Confirm overlay mapping for the parcel on the Town’s Zoning Map / Planned Development Map (§ 16-14.020)
Determine whether project wants to claim AHO incentives; if so, certify the affordability mix and prepare deed restrictions for required minimum periods (see § 16-23.030(D))
Prepare Site Plan & Architectural Review submittal or Conditional Use Permit package as required by the overlay (HPO exterior changes require Director approval of Minor Alteration SPR at a minimum) (§ 16-23.060(C))
For RMP/NC AHO projects: assemble evidence for requested incentive(s) (parking reductions, density increases) and show why project meets Review Authority criteria (§ 16-23.050, § 16-23.040)
If property is in the F overlay, obtain required flood documentation, follow Chapter 13D requirements, and coordinate with the Town Engineer (§ 16-23.020(A))
Confirm whether state density-bonus rules apply and how they interact with the AHO incentives (§ 16-23.030(E) and § 16-70.110)
Check design guidance: Downtown Tiburon Design Handbook applicability for Downtown/HPO projects and design themes required by the overlay (§ 16-23.040, § 16-23.060)

Risks & Ambiguities

Issue	Why it matters	What to verify
Which overlay is mapped on a parcel	Overlay-specific rules can add restrictions (F) or grant incentives (AHO); misidentifying leads to wrong entitlement approach	Verify parcel designation on the Town’s Zoning Map / Planned Development Map (§ 16-14.020) and get staff confirmation
Qualification for AHO incentives	Incentives are conditional on meeting affordability percentages and deed restrictions; failing to meet them means no incentives	Confirm exact affordability mix, deed-restriction term, and whether moderate-income rental units count under § 16-23.030(D)
Interaction with State density bonus	State law can require different outcomes; the municipal AHO bonus has special interaction rules	Review § 16-23.030(E) and § 16-70.110; verify which density bonus (Town vs. State) controls the entitlement in your application
Historic Inventory status	HPO protections only apply to properties on the Local Historic Inventory; not all downtown parcels are automatically subject to the same review	Verify whether the building is listed in the Local Historic Inventory (referenced in § 16-23.020(D) and § 16-23.060) and ask staff for the Inventory record
Flood map currency	FEMA maps and elevation datums update over time; outdated data can cause surprise requirements	Confirm the current FIRM effective date and required datum (North American Vertical Datum 1988) as referenced in § 16-23.020(A); coordinate with the Town Engineer
Where dimensional specifics live	Table 2‑4 delegates many items to review processes; applicants may need discretionary approvals	Check Table 2‑4 and be prepared to show why requested lot coverage/setbacks/parking deviations are appropriate under § 16-23.040–.050

Plain‑English Summary

If your Tiburon property carries an overlay (Flood F, Affordable‑Housing RMP/AHO or NC/AHO, or Historic HPO), that overlay adds a second layer of rules on top of the underlying zone — sometimes stricter (flood or historic protection) and sometimes more permissive (density or parking incentives for affordable housing). Check the Zoning Map, meet with staff early, and follow the specific overlay sections in the Zoning Ordinance when assembling your application. § 16-23.010–.060 contain the controlling rules.

Source References

Tiburon Zoning Ordinance, Title IV, Chapter 16 — Overlay Zones: § 16-23.010 (Purpose)
Tiburon Zoning Ordinance — Purposes of Overlay Zones: § 16-23.020 (F, RMP/AHO, NC/AHO, HPO)
Tiburon Zoning Ordinance — Affordable Housing Overlay: § 16-23.030, § 16-23.040, § 16-23.050 (permitted uses, Table 2‑4, incentives)
Tiburon Zoning Ordinance — Historic Protection Overlay: § 16-23.060 (uses, standards, review principles)
Tiburon Zoning Map/Map adoption: § 16-14.020 (Zoning Map and Zones)
Interaction with State density bonus: § 16-70.110 (State‑mandated Density Bonus) and § 16-23.030(E)

Internal resource pages (first-mention links used above):

Tiburon Zoning Overview: /us/california/tiburon
Tiburon Zoning: /us/california/tiburon/zoning
Tiburon Development Standards: /us/california/tiburon/development-standards
Tiburon Parking: /us/california/tiburon/parking
Tiburon Design Review: /us/california/tiburon/design-review
Tiburon Historic Preservation: /us/california/tiburon/historic-preservation
Tiburon ADUs: /us/california/tiburon/adu
California Building Standards Code: /us/california/building-codes

Sources

Retrieved passages

CBC § 16 (Article II) High relevance
Tiburon Zoning Code (Article II) High relevance
CBC § 020 (Chapter 13D) High relevance
Tiburon Zoning Code (Section 16-23.040) High relevance
Tiburon Zoning Code (Section 16-52.040) High relevance
Tiburon Zoning Code (Section 16-70.030) High relevance
Tiburon Zoning Code (Section 16-23.050) Medium relevance
Tiburon Zoning Code (Article X) Medium relevance

Cited sections

Official Tiburon code library

Frequently asked questions

What overlay zones exist in Tiburon and where are they described?

Tiburon’s ordinance lists the F (Flood Hazard), RMP/AHO (Residential Multiple Planned/Affordable Housing Overlay), NC/AHO (Neighborhood Commercial/Affordable Housing Overlay), and HPO (Historic Protection Overlay). The overlay rules and purposes are codified under § 16-23.010–.060 of the Zoning Ordinance.

How do I know whether my parcel is in an overlay zone?

Confirm on the Town’s adopted Zoning Map and Planned Development Map as incorporated by reference in § 16-14.020; if the map shows an overlay symbol for your parcel, that overlay’s rules apply. Always verify with Town staff for the official mapping.

What do the Affordable Housing Overlays require to get incentives?

To qualify for RMP/AHO or NC/AHO incentives you must meet the overlay’s affordability qualifications (including the required percentages of very-low, low, and moderate units, deed‑restriction terms, and any special‑needs set‑asides) and follow the development standards in Table 2‑4. See § 16-23.030(D) and § 16-23.040–.050.

What review is required for changes to a building in the Historic Protection Overlay?

Exterior alterations to buildings in the HPO generally require the Director’s approval of a Site Plan and Architectural Review application for Minor Alterations, and projects are reviewed for consistency with the Downtown Tiburon Design Handbook and the Local Historic Inventory; see § 16-23.060(B–C).

Can the Town reduce parking requirements for an AHO project?

Yes — the ordinance allows the Review Authority to reduce parking standards “within reason” for qualifying affordable housing projects, and it explicitly permits shared counting of parking between commercial and residential uses in NC/AHO projects where appropriate; see § 16-23.050(A.3) and § 16-23.050(B.3). For specific parking counts, consult the Town’s parking standards.

How does the Flood Hazard Overlay affect building approvals?

If your property is in the F overlay, construction must comply with the Town’s Flood Damage Prevention chapter (Municipal Code Chapter 13D), the Town Engineer acts as floodplain administrator, and FEMA Flood Insurance Rate Maps are incorporated by reference; see § 16-23.020(A). Confirm required base‑flood elevations and any floodproofing measures with the Town Engineer.

Do AHO incentives combine with the State density bonus?

The AHO incentives are separate from the State density bonus; the ordinance describes a particular interaction and exception (for example, certain AHO density rules) and references state-mandated density bonus procedures in § 16-70.110 — review both provisions early to determine the controlling entitlement path. Verify with the jurisdiction for project-specific application.

What design guidance applies to overlay projects in Downtown Tiburon?

The ordinance requires that improvements in Downtown be reviewed using the goals and principles of the Downtown Tiburon Design Handbook; this guidance is called out for overlay development review in § 16-23.040 and § 16-23.060. Expect the Design Handbook to steer choices on materials, massing, and historic compatibility.

If I have an accessory dwelling unit (ADU), do overlay rules apply?

Overlay rules apply where mapped regardless of ADU status. ADU/subordinate-dwelling rules are governed elsewhere in the code (see the Town’s ADU provisions); overlay standards (for example, flood or historic rules) can still constrain ADU siting and design. See § 16-23.010–.060 and the ADU chapter for details. Verify with the jurisdiction for lot-specific conditions.

Who is the decision-maker for overlay deviations or incentives?

The Review Authority (Design Review Board, Planning Commission, Town Council, Director or their designee as identified in the code) determines whether to grant discretionary approvals, deviations, or incentives; refer to the applicable overlay subsections and the ordinance’s administrative rules for process and appeal rights. See the definitions and administrative responsibilities in Article I and the Review Authority definition in Article X. ---

Ask about any Tiburon property

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

Start Free Trial