A. The purpose of this chapter is to establish objective standards and regulations to govern the development of two (2) unit residential development and urban lot splits on properties within the R-1 First Residential Zoning District and any Planned Development (P-D) Districts where single-family residential uses are allowed within the City of Larkspur. The establishment of these regulations will result in the orderly subdivision and development of qualified residential development and/or subdivision projects while ensuring that the new units are consistent with the City’s character and do not create any significant impacts with regard to public infrastructure or public safety. The regulations are established to implement the requirements under California Government Code Sections 65852.21 and 66411.7.

B. The provisions of this chapter shall be the primary regulations for the subdivision of an R-1 or P-D District lot to develop up to two (2) units on one (1) legal parcel and up to four (4) units on two (2) legal parcels in the R-1 Zoning District. To the extent that an aspect of the subdivision of land for or development of primary dwelling units is not addressed by this chapter, other provisions of the municipal code shall apply. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

“Accessory dwelling unit” (“ADU”) shall have the same meaning as set forth in Larkspur Municipal Code Section 18.23.020.

“Acting in concert with the owner” means a person that has common ownership or control of the subject parcel with the owner of the adjacent parcel, a person acting on behalf of, acting for the predominant benefit of, acting on the instructions of, or actively cooperating with, the owner of the parcel being subdivided.

“Adjacent parcel” means any parcel of land that is (1) touching the parcel at any point; (2) separated from the parcel at any point only by a public right-of-way, private street or way, or public or private utility, service, or access easement; or (3) separated from another parcel only by other real property which is in common ownership or control of the applicant.

“Common ownership or control” means properties owned or controlled by the same person, persons, or entity, or by separate entities in which any shareholder, partner, member, or family member of an investor of the entity owns ten (10) percent or more of the interest in the property.

“Conservation easement” means restrictive covenants that run with the land and bind upon successive owners that protect against future development such as preservation of open space, scenic, riparian, historical, agricultural, forested, or similar conditions. Open space and riparian easements are included in this definition.

“Flag lot” means a parcel that has less than the minimum required frontage on a public or private street, has access to a public or private street by a narrow strip of land, and the largest portion of the lot is situated behind adjoining lots which front on a public or private street.

“Junior accessory dwelling unit” (“JADU”) shall have the same meaning as set forth in Larkspur Municipal Code Section 18.23.020.

“Low income household” has the meaning set forth in Health and Safety Code Section 50079.5, as may be amended.

“Moderate income household” has the meaning set forth in Health and Safety Code Section 50093, as may be amended.

“Newly created lot” means a lot created by an urban lot split.

“Primary dwelling unit” (also called a residential dwelling unit or residential unit) is typically a single-family residence or a residential unit within a multifamily residential development. A primary unit is distinct from an ADU or a JADU. Examples of primary units include a single-family residence (i.e., one (1) primary unit) and a duplex (i.e., two (2) primary units). In this chapter, the terms “unit,” “housing unit,” “residential unit,” and “housing development” mean primary unit(s) unless specifically identified as an ADU or JADU.

“Private road” means a road, way, or street in private ownership and under private maintenance, not offered for dedication as a public road, way, place, or street, which affords the principal means of access to three (3) or more lots or parcels which do not have frontage on a public street.

“Urban lot split” means a subdivision of an existing parcel into no more than two (2) separate parcels pursuant to the provisions of this chapter and Government Code Section 66411.7, as may be amended.

“Very low income household” has the meaning set forth in Health and Safety Code Section 50105, as may be amended. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

A. Any parcel that was established through a prior exercise of a lot split as provided for in this chapter or Government Code Section 66411.7.

B. Any parcel adjacent to another parcel where either the owner of that adjacent parcel or any person acting in concert with the owner has previously subdivided that adjacent parcel using the provisions in this chapter or Government Code Section 66411.7.

C. Any parcel located within a historic district or included on the State Historic Resources Inventory, as defined in Section 5020.1 of the Public Resources Code, or a parcel within a site with a structure that is designated or listed as a City of Larkspur or Marin County landmark or historic property or district pursuant to a City of Larkspur or Marin County ordinance.

D. Any parcel where the lot split would require the demolition or alteration of any of the following types of housing:

E. Any parcel fully encumbered with an open space or conservation easement or identified for conservation in an adopted natural community conservation plan pursuant to the Natural Community Conservation Planning Act (Chapter 10 (commencing with Section 2800) of Division 3 of the Fish and Game Code), habitat conservation plan pursuant to the Federal Endangered Species Act of 1973 (16 U.S.C. Section 1531 et seq.), or other adopted natural resource protection plan.

F. Any parcel that is designated prime farmland or farmland of statewide importance, as defined pursuant to United States Department of Agriculture land inventory and monitoring criteria, as modified for California, and designated on the maps prepared by the Farmland Mapping and Monitoring Program of the Department of Conservation, or land zoned or designated for agricultural protection or preservation by a local ballot measure.

G. Any parcel containing wetlands, as defined in the United States Fish and Wildlife Service Manual, Part 660 FW 2 (June 21, 1993), that would prevent the development of the property.

H. Any parcel within a very high fire hazard severity zone, as determined by the Department of Forestry and Fire Protection pursuant to Government Code Section 51178, or within a high or very high fire hazard severity zone as indicated on maps adopted by the Department of Forestry and Fire Protection pursuant to Section 4202 of the Public Resources Code. This subsection does not apply to parcels that have been excluded from specific hazard zones by actions of the City pursuant to Government Code Section 51179(b), or parcels that have adopted fire hazard mitigation measures pursuant to existing building standards or state fire mitigation measures applicable to the development.

I. Any parcel with a hazardous waste site that is listed pursuant to Government Code Section 65962.5, or a hazardous waste site designated by the Department of Toxic Substances Control pursuant to Section 78760 et seq. of the Health and Safety Code, unless the State Department of Public Health, State Water Resources Control Board, or Department of Toxic Substances Control has cleared the site for residential use or residential mixed uses.

J. Any parcel within a special flood hazard area subject to inundation by the one (1) percent annual chance flood (one hundred (100) year flood) as determined by the Federal Emergency Management Agency (FEMA) in any official maps published by FEMA. However, a lot split and/or development project may be located on a parcel described in this subsection if (1) the parcel is otherwise eligible for approval under the provisions of this chapter and (2) the project applicant is able to satisfy all applicable federal qualifying criteria demonstrating either of the following are met:

K. Any parcel within a regulatory floodway as determined by FEMA in any official maps published by FEMA, unless the lot split and/or development project has received a no-rise certification in accordance with Section 60.3(d)(3) of Title 44 of the Code of Federal Regulations.

L. Any parcel containing habitat for protected species identified as candidate, sensitive, or species of special status by state or federal agencies, fully protected species, or species protected by the Federal Endangered Species Act of 1973 (16 U.S.C. Section 1531 et seq.), the California Endangered Species Act (Chapter 1.5 (commencing with Section 2050) of Division 3 of the Fish and Game Code), or the Native Plant Protection Act (Chapter 10 (commencing with Section 1900) of Division 2 of the Fish and Game Code).

M. Parcels that are not in a single-family residential zone. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

A. A parcel map and a subdivision application as set forth in Larkspur Municipal Code Chapter 17.32 shall be submitted to the City for all proposed lot splits. Urban lot splits are subject to the Subdivision Map Act (Division 2 (commencing with Government Code Section 66410)), except as otherwise expressly provided in Government Code Section 66411.7.

B. The lot split shall result in no more than two (2) parcels (one (1) net new parcel) of approximately equal lot area; provided, that one (1) parcel shall not be smaller than forty (40) percent of the lot area of the original parcel proposed for subdivision. In no instance shall any resulting lot be smaller than one thousand two hundred (1,200) square feet in area.

C. Existing parcels shall be split along the longest property line dimension.

D. The front property line of any newly created lot shall be the lot line that is closest to or parallel to the public or private road that serves the parcel.

E. Easements for access and public and private utilities shall be provided for any newly created parcel that does not front on a public or private street. For the purposes of determining lot area for the subdivision, areas covered by access easements shall be deducted from the lot area of the parcel on which they are located unless such deduction would prevent the resulting parcel from having at least one thousand two hundred (1,200) square feet in lot area.

F. Separate utility meters shall be provided for each unit prior to recordation of the parcel map.

G. All newly created parcels shall be connected to public sewer or provide a private wastewater system that is fully contained within the new property boundaries.

H. No setbacks shall be required for an existing primary structure on the property from a proposed lot line.

I. The lot split is subject to all impact or development fees related to the creation of a new parcel.

J. Upon receipt of a lot split application using the provisions of this chapter, the City shall notify all property owners and occupants within a five hundred (500) foot radius from the subject property that a parcel map has been filed with the City.

K. A note on the parcel map and a recorded deed restriction shall be applied to all newly created parcels indicating that the parcel was split using the provisions of this chapter and that no further subdivision of the parcels is permitted.

L. Prior to the recordation of the parcel map, the subdivision applicant shall sign and record an affidavit stating that the applicant intends to reside in one (1) of the housing units as their principal residence for a minimum of three (3) years from the date of the approval of the urban lot split. This requirement shall not apply if the applicant is a community land trust, or a qualified nonprofit corporation as provided in Sections214.15 and 402.1 of the Revenue and Taxation Code.

M. Any approved lot created under this chapter shall be subject to the expiration and extension requirements of Section 66452.6 of the California Government Code, as may be amended.

O. If pedestrian access from the street is required by the Building Code or Fire Code or provided:

P. Front lot lines must conform to a minimum public street frontage requirement of fifty (50) feet with the following exception:

Q. Interior lots with no lot lines fronting on a public or private right-of-way are allowed as long as they are served by an access easement from a public or private street that serves no more than two (2) parcels and all of the following are met:

R. Lot lines shall be:

S. Lot lines shall not:

A. A proposed housing development containing no more than two (2) primary dwelling units within the R-1 First Residential Zoning District and any Planned Development (P-D) Districts where single-family residential uses area allowed shall be considered ministerially, without discretionary review or a hearing, if the proposed housing development meets all of the following requirements:

A. The maximum floor area permitted on a lot shall be determined through Larkspur Municipal Code Section 18.35.050. Notwithstanding the immediately preceding sentence, eight hundred (800) square feet of additional floor area is permitted for an ADU and eight hundred (800) square feet of additional floor area and development area is permitted for a second primary dwelling unit, even if the additional square feet added by an ADU or second primary dwelling unit, or both, exceed the maximum floor area and maximum dwelling area.

B. Each parcel is permitted up to two (2) primary residential units and ADUs and junior ADUs as permitted under Larkspur Municipal Code Chapter 18.23.

C. Setbacks. The minimum setback for any new primary dwelling unit created under this chapter shall be consistent with Larkspur Municipal Code Title 20 standards for the T3 Edge Neighborhood Zone except that four (4) foot side and rear property lines are permitted.

Exceptions: No setback is required for a new dwelling unit constructed in the same location and to the same dimensions as an existing structure.

D. The maximum height shall be as provided in Larkspur Municipal Code Section 20.03.030(3), T3 Edge Neighborhood (T3EN) Allowable Building Height and Slope Design Standards.

E. One (1) parking space shall be provided for each dwelling unit and located and designed per Larkspur Municipal Code Section 18.56.040, except that a parking space shall not be required for a new primary dwelling unit in either of the following circumstances:

F. A solid (no openings) one (1) hour rated fire wall is required between any two (2) dwelling units, except a primary dwelling unit and a JADU for that unit.

I. All newly created dwelling units shall be connected to public sewer or provide a private wastewater system that is fully contained within the property boundaries.

K. All outdoor patios, covered patios, decks, and other hardscape shall meet the minimum front, side, and rear yard setbacks as set forth in Larkspur Municipal Code Title 20 for the T3 Edge Neighborhood Zone.

L. Coverage and natural state limitations in Larkspur Municipal Code Sections 18.20.050 and 18.34.080 shall apply except to the extent that they would preclude primary dwelling units and to the extent necessary to make it feasible to comply with the required minimum emergency access and required vehicle parking standards.

M. No dwelling unit shall be rented for a period of less than thirty (30) days and cannot be occupied as a short-term rental unit. Prior to occupancy, the property owner shall record a deed restriction specifying that no dwelling unit shall be occupied as a short-term rental unit.

N. If there are two (2) primary units, one (1) primary unit may be rented separately from the second primary dwelling unit.

O. Development projects pursuant to this section shall be subject to all impact or development fees related to the development of a new dwelling unit.

P. Grading shall be limited to a total of twenty-five (25) cubic yards of combined cut and fill for each new primary dwelling unit proposed, exclusive of grading for the minimum required emergency access and required vehicle parking. Grading authorized by this subsection shall be solely for the purpose of developing primary dwelling units and not for other improvements on the parcel. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

A. Each parcel is permitted up to two (2) units. All three (3) unit types permitted in the R-1 Zoning District or in a Planned Development District permitting single-family residential uses (i.e., primary unit, ADU, and JADU) count toward this two (2) unit limit. For example, the limit could be reached on each lot by creating two (2) primary units, or a primary unit and an ADU, or a primary unit and a JADU.

B. Maximum Floor Area. The maximum gross floor area shall be as set forth in Larkspur Municipal Code Chapter 18.35, Residential Floor Area Ratios, for lots in the First Residential District or eight hundred (800) square feet per unit, whichever is greater.

C. Coverage and natural state limitations shall apply except to the extent that they would preclude primary dwelling units allowed under this section and to the extent necessary to make it feasible to comply with the required minimum emergency access, and required vehicle parking, standards.

D. Setbacks. The minimum setbacks for any new primary dwelling unit created pursuant to this chapter shall comply with the Larkspur Municipal Code Title 20 standards for the T3 Edge Neighborhood Zone except that side and rear setbacks shall be four (4) feet.

Exceptions: No setback is required for a new primary dwelling unit constructed in the same location and to the same dimensions as an existing structure on the property.

E. The maximum height of all new primary dwelling units and any additions or modifications to existing primary dwelling units shall be as provided in Larkspur Municipal Code Section 20.03.030(3), T3 Edge Neighborhood (T3EN) Allowable Building Height and Slope Design Standards.

F. If there is an existing primary dwelling unit not created pursuant to this chapter on either parcel, then said existing primary dwelling unit shall maintain the existing number of parking spaces. In all other instances, one (1) parking space shall be located and designed per Larkspur Municipal Code Section 18.56.040 and is required for each primary dwelling unit, except as provided below:

G. If a parcel is proposed to be developed with two (2) primary dwelling units configured as a duplex, then a solid one (1) hour fire wall between the units is required, with no openings. In addition, a deed restriction shall be recorded stipulating that the duplex shall be maintained as two (2) separate units.

H. If a parcel resulting from a subdivision utilizing this chapter is developed with two (2) units, then the applicant or the property owner shall record a deed restriction stipulating that no further subdivision of the parcel pursuant to this section is permitted.

I. The project applicant or property owner shall sign and record an affidavit stating that the applicant or owner intends to reside in one (1) of the dwelling units on the property for three (3) years from the date of the approval of the subdivision.

J. All newly created dwelling units shall be connected to public sewer or provide a private wastewater system that is fully contained within the property boundaries.

K. All portions of the primary dwelling unit shall meet the required setbacks as provided in this section.

L. All outdoor patios, covered patios, decks, and other hardscape shall meet the minimum front, side, and rear yard setbacks as provided in Larkspur Municipal Code Title 20, for the T3 Edge Neighborhood Zone.

M. No dwelling unit shall be rented for a period of less than thirty (30) days and cannot be occupied as a short-term rental unit. Prior to occupancy, the property owner shall record a deed restriction specifying that no dwelling unit shall be occupied as a short-term rental unit.

N. One (1) primary dwelling unit may be rented separately from a second primary dwelling unit.

O. Any development constructed in accordance with this section shall be subject to all impact or development fees related to the development of a new dwelling unit.

P. Grading shall be limited to a total of twenty-five (25) cubic yards of combined cut and fill for each new primary dwelling unit proposed, exclusive of grading for the minimum required emergency access and required vehicle parking. Grading authorized by this subsection shall be solely for the purpose of developing primary dwelling units and not for other improvements on the parcel. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

A. The design of the primary dwelling unit shall comply with Larkspur Municipal Code Title 20 standards for the T3 Edge Neighborhood District and other relevant provisions of Larkspur Municipal Code Title 20.

D. All new dwelling units are required to have fire sprinklers.

E. Structures shall not be located in areas encumbered by a recorded easement, including, but not limited to, public utility easements, conservation easements, access easements, pedestrian pathway easements and open space easements.

F. All electrical and utility services to a new dwelling unit shall be undergrounded.

G. Structures constructed per this chapter shall comply with California Fire Code requirements as adopted and amended by the City of Larkspur for emergency vehicle access and water supply.

H. No heritage tree, as defined in Larkspur Municipal Code Chapter 12.16, shall be removed for construction of a primary dwelling unit unless the City Arborist determines that the tree is dead, has irreversible decline of more than fifty (50) percent crown dieback or trunk decay, is hazardous by having a leaning angle of thirty (30) degrees or more from vertical standing or is infested by pests or disease of any kind; or its removal is necessary to accommodate at least one hundred (100) square feet of floor area of the proposed primary unit. An applicant may apply for a discretionary heritage tree removal permit to remove a tree that does not meet the criteria in this section.

I. Any parcel within a very high fire hazard severity zone, as determined by the Department of Forestry and Fire Protection pursuant to Government Code Section 51178, or within a high or very high fire hazard severity zone as indicated on maps adopted by the Department of Forestry and Fire Protection pursuant to Section 4202 of the Public Resources Code, shall include adopted fire hazard mitigation measures pursuant to existing building standards or state fire mitigation measures applicable to the development.

J. All detached structures shall maintain a minimum ten (10) foot separation.

K. Accessory buildings shall be permitted in compliance with Larkspur Municipal Code Section 18.20.070, and subject to all standard limitations prescribed for height in Larkspur Municipal Code Title 20 and floor area, site coverage, and natural state in this title.

L. All curb cuts and driveway access shall conform to Standard 210 of the Central Marin Fire Department. (Ord. 1091 § 3 (Exh. A), 2025; Ord. 1061 § 2 (Exh. A), 2022; Ord. 1057 § 3, 2022; Ord. 1055 § 2 (Exh. A), 2021)

A. A building permit application for new units and a tentative parcel map application for an urban lot split application, as applicable based on the applicant’s proposal, shall be filed with the Community Development Department and shall be accompanied by the required fee and all supporting application materials as follows:

B. Within thirty (30) calendar days of submittal, the City shall determine application completeness. If incomplete, the City shall issue a comprehensive written list of missing items, limited to those on the official submittal checklist.

C. If the application is complete, the Community Development Director or their designee shall approve the application ministerially, or shall return in writing a full set of comments to the applicant with a list of items that are defective or deficient and a description of how the application can be remedied by the applicant, within sixty (60) days from the date the City received the complete application. Any associated demolition permit shall be reviewed and issued concurrently.

D. A complete application is deemed approved if the City fails to approve or return comments to the applicant as described above within sixty (60) days of receiving the complete application.

E. An application for the subdivision of land for or development of a primary dwelling unit may be denied if the Chief Building Official makes a written finding, based upon a preponderance of the evidence, that the proposed housing development project would have a specific, adverse impact, as defined and determined in Section 65589.5(d)(2) of the California Government Code, upon public health or safety and for which there is no feasible method to satisfactorily mitigate or avoid the specific, adverse impact.

F. The Community Development Director’s decision shall be final.

G. Within twenty-four (24) months from the date of approving an application and tentative map, the applicant shall cause the parcel split to be surveyed and a final parcel map to be prepared and submitted for approval and recording, with all conditions imposed and fulfilled and all information provided as identified in this chapter. A subsequent approval of the tentative map upon fulfillment of conditions shall not be construed as extending the time within which the final parcel map may be filed for approval, but for a good cause shown, the Community Development Director or designee may grant an extension of time not exceeding one (1) year. Failure to file a final parcel map within the original and/or extended time period granted as provided shall terminate the application and all proceedings.

A. It is unlawful for any person to violate any provision or to fail to comply with any of the requirements of this chapter. A property will be found in violation of this chapter when the dwelling unit has been created without the required City approvals or does not comply with standards and deed restrictions established in this chapter. Violations are subject to the enforcement penalties and procedures of Larkspur Municipal Code Chapter 9.24.

B. In addition to the enforcement penalties and procedures included in Larkspur Municipal Code Chapter 9.24, the City may pursue any remedies provided by law against the owner found to be in violation of this chapter, or a property not maintained in conformance with this chapter including: