Tiburon Municipal Code § 16-77 Two-Unit Housing Developments

Editor's note— Ord. No. 612, § 3(Exh. B), adopted September 3, 2025, amended Art. VIII, Section 16-77, in its entirety to read as herein set out. Former Art. VIII, §§ 16-77.010—16-77.040, pertained to similar subject matter, and derived from Ord. No. 597 N.S, § 3, adopted May 18, 2022.

The purpose of this chapter is to provide procedures and development standards for the establishment of two-unit housing developments pursuant to Government Code section 65852.21. To accomplish this purpose, the regulations outlined herein are determined to be necessary for the preservation of the public health, safety, and general welfare, and for the promotion of orderly growth and development.

Owners of real property or their representatives may continue to exercise rights for property development in conformance with the Zoning Code. Development applications that do not satisfy the definitions for a two-unit housing development in Article 16-77 (Definitions) shall not be subject to this Ordinance. The provisions of this Division shall be interpreted in a manner which is the most limiting on the ability to create a two-unit housing development, but which is consistent with State law. The provisions of this division shall supersede and take precedence over any inconsistent provision of the Town Code to the extent necessary to effect the provisions of this division.

(Ord. No. 612, § 3(Exh. B), 9-3-2025)

(a) Two-unit housing development. A two-unit housing development is a development containing no more than two primary dwelling units and which development either (1) proposes two new units, or (2) proposes to add one new unit to one existing unit.

(b) "Nonconforming zoning condition" means a physical improvement on a property that does not conform with current zoning standards.

(c) "Major transit stop" as defined in Public Resources Code section 21155, is:

(1) A high-quality transit corridor with fixed route bus service with service intervals no longer than fifteen minutes during peak commute hours.

(2) A major transit stop included in the Bay Area Regional Transportation Plan.

(3) The intersection of two or more major bus routes with a frequency of service interval of fifteen minutes or less during the morning and afternoon peak commute periods.

(4) A ferry terminal served by either a bus or rail transit service.

(5) An existing rail or bus rapid transit station.

(Ord. No. 612, § 3(Exh. B), 9-3-2025)

(a) Ministerial review. A two-unit housing development shall be ministerially approved, without discretionary review or hearing, if the proposed housing development meets all provisions of this chapter.

(b) Administrative permit. Applicants for two-unit housing developments shall submit an administrative permit application in addition to a building permit application.

(c) The town shall act on an administrative permit application for a two-unit housing development within sixty days of receipt of a complete application. If the town fails to act on a complete application within sixty days, the application will be deemed approved. If the applicant requests a delay in writing, the sixty-day time period shall be tolled for the period of the delay. The town has acted on the application if it:

(1) Approves or denies the building permit for the two-unit development; or

(2) Informs the applicant in writing of a list of items that are defective or deficient and a description of how the application can be remedied to comply with this chapter or other applicable laws and regulations.

(d) Building permits. Approval of a two-unit housing development application shall be required prior to acceptance of an application for building permit(s) for the new and/or modified primary dwelling unit(s) comprising the two-unit housing development.

(e) Appeals. Two-unit housing application decisions are ministerial and are not subject to an appeal.

(Ord. No. 612, § 3(Exh. B), 9-3-2025)

(a) Zoning district. A parcel that is located within a single-family residential zone.

(b) Legal parcel. A parcel which has been legally created in compliance with the Subdivision Map Act (Government Code Section 66410 et seq.) and the Town's Subdivision Regulations in effect at the time the parcel was created. Applications for a two-unit housing development will only be accepted on parcels with either a recorded parcel map or certificate of compliance. When both an urban lot split and two-unit housing development application are submitted simultaneously, no construction or building permits for new construction or grading activities may be issued until the new parcel map for the urban lot split approval has been recorded.

(c) Adverse impact upon health and safety. A proposed two-unit housing development shall be denied if the building official makes a written finding, based upon a preponderance of the evidence, that the proposed two-unit housing development would have a specific, adverse impact, as defined and determined in Government Code section 65589.5, subdivision (d)(2), upon public health and safety and for which there is no feasible method to satisfactorily mitigate or avoid the specific, adverse impact.

(d) Limitations on approval. A proposed two-unit housing development shall not be eligible for approval pursuant to this chapter if any of the following circumstances apply:

(1) The two-unit housing development would require demolition or alteration of "protected housing." Protected housing includes:

a. Housing that is subject to a recorded covenant, ordinance or law that restricts rents to levels affordable to persons and families of moderate, low, or very low income.

b. Housing that is subject to rent control through valid local rent control provisions.

c. Housing that has been occupied by a tenant in the last three years.

(2) The two-unit housing development would be located on a parcel on which the owner has withdrawn it from renting or leasing under Government Code section 7060 within fifteen years preceding the development application (i.e., an exit of the rental housing business pursuant to the Ellis Act).

(3) The two-unit housing development would be located within a historic district, is included on the State Historic Resources Inventory, or is within a site that is legally designated or listed as a town or county landmark or historic property or district.

(4) The two-unit housing development would be located in any of the specified designated areas set forth in Government Code section 65913.4, subdivision (a)(6), subparagraphs (B) to (K), inclusive.

(Ord. No. 612, § 3(Exh. B), 9-3-2025)

The following objective development standards shall apply to two-unit housing developments. In addition to these standards, all provisions of the California Building Code shall apply to two-unit housing developments.

(a) General development standards. The following objective zoning standards supersede any other standards to the contrary that may be provided elsewhere in the Zoning Code, as they pertain to a two-unit housing development under Government Code section 65852.21. Two-unit housing developments shall be constructed only in accordance with the following objective zoning standards, except as provided by subsection (d)(1), below.

(1) Building height. Maximum building height shall be as specified by the applicable zoning district for the main structure.

(2) Setbacks. Two-unit housing developments and attached garages shall be subject to the setback requirement of four feet for the rear and side yards. Front yard setbacks shall be determined per the applicable zoning district. Detached garages and detached accessory structures shall meet the setback requirements specified per the zoning district.

(3) Two-unit housing developments may either be detached or attached, as long as attached structures meet building code safety standards and are sufficient to allow separate conveyance.

(4) The maximum floor area ratio and lot coverage shall be as specified by the applicable zoning regulations. Notwithstanding the floor area ratio and lot coverage standards by the applicable zoning regulations, a new two-unit housing development with unit sizes of eight hundred square feet or less shall be permitted.

(5) For flag/corridor lots, the gross lot size includes the access corridor for the purposes of determining maximum floor area ratio and lot coverage as follows:

a. When an easement is used to provide access, the access corridor is included in the gross lot size for the lot granting the easement; and

b. When the access corridor is owned in-fee and is part of the rear lot, the access corridor is included in the gross lot size for the rear lot.

(6) Parking. One off street parking space per unit shall be required, except in either of the following instances:

a. The parcel is located within one-half mile walking distance of either a high-quality transit corridor, as defined in Public Resources Code section 21155, subdivision (b), or a major transit stop, as defined in Public Resources Code section 21064.3.

b. There is a car share vehicle located within one block of the parcel.

(b) General requirements and restrictions. The following requirements and restrictions apply to all proposed two-unit developments:

(1) Short-term rentals are prohibited. The rental of any two-unit housing development shall be for a term of longer than thirty days.

(2) Lighting. Per 16-30.070, exterior lighting shall be shielded and/or directed such that it does not produce glare visible from off-site or illuminate adjacent or nearby property.

a. All proposed exterior lighting shall be shielded downlighting.

b. All skylights shall be bronzed or tinted, and no lights shall be placed in or directed up into the wells.

(3) Projections into setbacks. Per TMC 16-30.030 (F), the ordinary projection of sills, bay windows, cornices, architectural features, entry roofs and eaves may extend beyond the wall of the structure and into the front, side and rear setbacks; provided, however, that none shall project into a minimum setback more than three feet.

(4) Structures beyond the two-unit development. Any proposed exterior improvement or structures beyond the proposed two-unit development shall comply with the standards under TMC 16-52.020. Ministerial review is only applicable for the structure of the two-unit development.

(5) Applicant shall submit a water budget consistent with the Model Water Efficient Landscape Ordinance (MWELO) demonstrating water use of no more than five hundred gallons per ten thousand square feet of lot area per day. The landscape area of single-family residence, or duplexes shall be limited to no more than twenty percent of the newly landscape area with a max allowance of twelve hundred square feet of grass.

(6) Any protected tree to be removed as part of a new residential unit shall require a tree removal permit under Chapter 15A.

(7) Fire District Regulations. The two-unit development shall comply with all applicable Fire District regulations, subject to provisions and limitations set forth in Government Code section 65852.2.

(c) Exceptions to development standards. Notwithstanding subsection (b) of this section, all development standards shall be subject to the following exceptions:

(1) Where each of the units of a two-unit housing development is no greater than eight hundred square feet in size with side and rear setbacks of at least four feet, the two-unit housing development shall be permitted regardless of any development standard that would prevent construction of the units.

(2) No setback shall be imposed for a two-unit housing development constructed in the same location and to the same dimensions as an existing structure.

(Ord. No. 612, § 3(Exh. B), 9-3-2025)