Chapter 17.31

TWO-UNIT PROJECTS

Sections:

• 17.31.010 Purpose. 17.31.020 Definition.

• 17.31.030 Application.

• 17.31.040 Approval. 17.31.050 Requirements.

The purpose of this chapter is to allow and appropriately regulate two-unit projects in accordance with California Government Code Section 65852.21. (Ord. 23-4 § 5 (Exh. A))

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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“Two-unit project” means the development of two primary dwelling units or, if there is already a primary dwelling unit on the lot, the development of a second primary dwelling unit on a legally subdivided lot in accordance with the requirements of this chapter. (Ord. 23-4 § 5 (Exh. A))

• A. An application for a two-unit project must be submitted on the city’s approved form.

• B. Only a complete application will be considered. The city will inform the applicant in writing of any incompleteness within thirty (30) days after the application is submitted.

C. The city may establish a fee to recover its costs for adopting, implementing, and enforcing this chapter of the code, in accordance with applicable law. The city council may establish and change the fee by resolution. The fee must be paid with the application. (Ord. 23-4 § 5 (Exh. A))

A. An application for a two-unit project is approved or denied ministerially, by the community development director, without discretionary review.

B. The ministerial approval of a two-unit project does not take effect until the city has confirmed that the required documents have been recorded, such as the deed restriction and easements.

C. The approval must require the owner and applicant to hold the city harmless from all claims and damages related to the approval and its subject matter.

D. The approval must require the owner and applicant to reimburse the city for all costs of enforcement, including attorneys’ fees and costs associated with enforcing the requirements of this code. (Ord. 23-4 § 5 (Exh. A))

A two-unit project must satisfy each of the following requirements:

A. Map Act Compliance. The lot upon which the two-unit project will be located must have been legally subdivided.

B. Zone. The two-unit project must be located in a single-family residential zone. For purposes of this section, single-family residential zones include the following zoning districts in the city: MR, LR, LR-1A, and WW.

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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• C. Lot Location. The two-unit project may not be located on a site that is any of the following:

  1. Prime farmland, farmland of statewide importance, or land that is zoned or designated for agricultural protection or preservation by the voters.

  2. A wetland.

  3. Within a very high fire hazard severity zone, unless the site complies with all fire hazard mitigation measures required by existing building standards.

  4. A hazardous waste site that has not been cleared for residential use.

  5. Within a delineated earthquake fault zone, unless all development on the site complies with applicable seismic protection building code standards.

  6. Within a one hundred (100) year flood hazard area, unless the site has either:

     • a. Been subject to a letter of map revision prepared by the Federal Emergency Management Agency and issued to the local jurisdiction; or

b. Meets Federal Emergency Management Agency requirements necessary to meet minimum flood plain management criteria of the National Flood Insurance Program.

7. Within a regulatory floodway, unless all development on the site has received a no-rise certification.

8. Land identified for conservation in an adopted natural community conservation plan, habitat conservation plan, or other adopted natural resource protection plan.

9. Habitat for protected species.

10. Land under conservation easement.

D. Not Historic. The two-unit project must not be located on a historic property or within a historic district that is included on the California Historical Resources Inventory. Further, the property upon which the two-unit project will be located also may not be or be within a site that is designated by ordinance to be within a historic preservation district, as a city or county landmark or as a historic property or district.

• E. No Impact on Protected Housing. The two-unit project must not require or include the demolition or alteration of any of the following types of housing:

  1. Housing that is income-restricted for households of moderate-, low-, or very low-income.

  2. Housing that is subject to any form of rent or price control through a public entity’s valid exercise of its police power.

  3. Housing, or a lot that used to have housing, that has been withdrawn from rental or lease under the Ellis Act (California Government Code Sections 7060 through 7060.7) at any time in the fifteen (15) years prior to submission of the urban lot split application.

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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4. Housing that has been occupied by a tenant in the last three years. The applicant and the owner of a property for which a two-unit project is sought must provide a sworn statement as to this fact with the application for the parcel map. The city may conduct its own inquiries and investigation to ascertain the veracity of the sworn statement, including, but not limited to, surveying owners of nearby properties; and the city may require additional evidence of the applicant and owner as necessary to determine compliance with this requirement.

• F. Unit Standards.

1. Floor Area Ratio, Height Limitations, Lot Coverage and Open Space Requirements. All existing standards in this title related to floor area ratio, height limitations, lot coverage and open space requirements shall apply to units constructed pursuant to this chapter, except to the extent that such standards would prevent two units of at least eight hundred (800) square feet each to be constructed on the lot upon which the units will be located.

2. Demolition Cap. The two-unit project may not involve the demolition of more than twenty-five percent (25%) of the existing exterior walls of an existing dwelling unless the site has not been occupied by a tenant in the last three years.

3. Setbacks.

   • a. Generally. All setbacks must conform to those objective setbacks that are imposed in the underlying zone.

   • b. Exceptions. Notwithstanding subsection (F)(3)(a) of this section:

     • i. Existing Structures. No setback is required for an existing legally established structure or for a new structure that is constructed in the same location and to the same dimensions as an existing legally established structure.

ii. The setbacks imposed by the underlying zone must yield to the degree necessary to avoid physically precluding the construction of up to two units on the lot or either of the two units from being at least eight hundred (800) square feet in floor area; but in no event may any structure be less than four feet from a side or rear property line.

iii. Front Setback Area. Notwithstanding any other part of this code, dwellings that are constructed pursuant to this chapter must be consistent with the front setback requirements of the underlying zoning district.

4. Parking. Required parking as set forth below must be on the same lot as the residential unit served. Each new dwelling unit constructed pursuant to this chapter must have at least one off-street parking space per unit unless one of the following applies:

• a. The parcel is located within one-half mile walking distance of either:

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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i. A corridor with fixed route bus service with service intervals no longer than fifteen (15) minutes during peak commute hours; or

• ii. A site that otherwise qualifies as a high-quality transit corridor as defined in Section 21155(b) of the Public Resources Code, or a major transit stop as defined in Section 21064.3 of the Public Resources Code.

• b. The parcel is located within one block of a permanent, marked location for car-share vehicle pick-up and drop-off.

5. Replacement Parking Required. When an existing garage, carport, or other covered parking structure is converted or demolished in order to construct a new unit, the required parking spaces that are displaced by the conversion or demolition shall be replaced on the same lot, and may be either covered or uncovered, in order to satisfy the automobile parking requirement of the existing residential unit.

6. Design Standards. Each new dwelling unit constructed pursuant to this chapter shall comply with all objective standards as set forth in this title as applicable in the underlying zoning district. Additionally, all units constructed pursuant to this chapter shall comply with all of the following:

• a. All exterior lighting must be limited to fully shielded light fixtures.

b. If a new dwelling is constructed pursuant to this chapter and any portion of the dwelling is less than thirty (30) feet from a property line that is not a public right-of-way line, then all windows and doors in that portion must either be (for windows) clerestory with the bottom of the glass at least six feet above the finished floor, or (for windows and for doors) utilize frosted or opaque glass.

• c. No rooftop decks shall be allowed on new dwelling units constructed pursuant to this chapter.

d. Upper story unenclosed landings, decks and balconies greater than twenty (20) square feet that face or overlook an adjoining property shall be located a minimum of fifteen (15) feet from the interior lot lines.

e. A two-unit residential project constructed pursuant to this chapter may not include a request for an exception to any objective standards by applying for a variance, modification, exception, waiver or other discretionary approval for height, density, setbacks, open yard, land use, or similar development standard.

f. On a site already developed with an existing residential unit, the new unit shall be designed and constructed to match the existing paint color and exterior building materials, including but not limited to siding, windows, doors, roofing, and exterior light fixtures.

g. If a two-unit residential project is proposed on a lot where no residential units currently exist, the units shall be constructed using the same architectural style, exterior building materials, colors and finishes.

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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7. Landscaping. Evergreen landscape screening must be planted and maintained between each dwelling and adjacent lots along interior lot lines (but not rights-of-way) as follows:

• a. At least one fifteen (15) gallon size plant shall be provided for every five linear feet of exterior wall. Alternatively, at least one twenty-four (24) inch box size plant shall be provided for every ten (10) linear feet of exterior wall.

  • b. Plant specimens must be at least six feet tall when installed. As an alternative, a solid fence of at least six feet in height may be installed. All landscaping must be drought tolerant.

c. A complete landscaping and irrigation plan shall be submitted and approved by the community development department prior to the issuance of building permits for a two-unit residential development.

8. Building Separation. Unless attached to and made part of another main building pursuant to the definition of accessory building in Chapter 17.32, Definition of Terms, no detached main building shall be closer than ten (10) feet to any other main building on the same lot; and no detached accessory building shall be closer than five feet to any other main or accessory building on the same lot; provided, that the

requirements of this subsection shall not apply if doing so would preclude the construction of two units of at least eight hundred (800) square feet each on the lot upon which the units will be located.

9. Building and Safety. All two-unit residential projects must comply with all current local building standards.

10. Stormwater and Runoff Pollution Control. All construction activity or development that occurs in furtherance of a two-unit project shall comply with all requirements of Chapter 13.32, Stormwater and Runoff Pollution Control.

• G. Separate Conveyance.

  1. Primary dwelling units on the lot may not be owned or conveyed separately from each other.

  2. Condominium airspace divisions and common interest developments are not permitted within the lot.

  3. All fee interest in the lot and all the dwellings must be held equally and undivided by all individual property owners.

• H. Notice of Construction.

1. At least thirty (30) business days before starting any construction of a two-unit project, the property owner must give written notice to all the owners of record of each of the adjacent residential parcels, which notice must include the following information:

• a. Notice that construction has been authorized;

• b. The anticipated start and end dates for construction;

• c. The hours of construction;

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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  - d. Contact information for the project manager (for construction-related complaints); and 

  - e. Contact information for the building division. 

2. This notice requirement does not confer a right on the noticed persons or on anyone else to comment on the project before permits are issued. Approval is ministerial. Under state law, the city has no discretion in approving or denying a particular project under this section. This notice requirement is purely to promote neighborhood awareness and expectation.

• I. Deed Restriction. Prior to obtaining a building permit for a two-unit project pursuant to this chapter, the owner must record a deed restriction, acceptable to the city, that does each of the following:

  1. Expressly prohibits any rental of any dwelling on the property for a period of less than thirty (30) days.

  2. Expressly prohibits any nonresidential use of the lot.

  3. Expressly prohibits any separate conveyance of a primary dwelling on the property, any separate fee interest, and any common interest development within the lot.

  4. If the lot is not created by an urban lot split, expressly requires the individual property owners to live in one of the dwelling units on the lot as the owners’ primary residence and legal domicile.

  5. States that the property is formed by an urban lot split and is therefore subject to the city’s urban lot split regulations, including all applicable limits on dwelling size and development.

• J. Basis for Denial—Specific, Adverse Impacts.

  1. Notwithstanding anything else in this section, the city may deny an application for a two-unit project if the chief building official makes a written finding, based on a preponderance of the evidence, that the project would have a “specific, adverse impact” on either public health and safety or on the physical environment and for which there is no feasible method to satisfactorily mitigate or avoid the specific adverse impact.

  2. “Specific, adverse impact” has the same meaning as in California Government Code Section 65589.5(d)(2): “a significant, quantifiable, direct, and unavoidable impact, based on objective, identified written public health or safety standards, policies, or conditions as they existed on the date the application was deemed complete” and does not include (a) inconsistency with the zoning ordinance or general plan land use designation or (b) the eligibility to claim a welfare exemption under Revenue and Taxation Code Section 214(g).

  3. The chief building official may consult with and be assisted by planning staff and others as necessary in making a finding of specific, adverse impact.

• K. Remedies. If a two-unit project violates any part of this code or any other legal requirement:

  1. The buyer, grantee, or lessee of any part of the property has an action for damages or to void the deed, sale, or contract.

  2. The city may:

The St. Helena Municipal Code is current through Ordinance 26-4, passed May 12, 2026.

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• a. Bring an action to enjoin any attempt to sell, lease, or finance the property.

b. Bring an action for other legal, equitable, or summary remedy, such as declaratory and injunctive relief.

c. Pursue criminal prosecution, punishable by imprisonment in county jail or state prison for up to one year, by a fine of up to ten thousand dollars ($10,000.00), or both; or a misdemeanor.

• d. Record a notice of violation.

• e. Withhold any or all future permits and approvals.

• f. Pursue all other administrative, legal, or equitable remedies that are allowed by law or the city’s code. (Ord. 23-4 § 5 (Exh. A))