A. 
The purpose of this chapter is to establish regulations to govern the subdivision of parcels within the single family residential ("RS") zoning district in the City of Mill Valley, as required by the state law regarding the subdivision of parcels enacted by Senate Bills No. 9 and 450 (Government Code Section 66411.7), as may be amended. The establishment of these regulations will result in the orderly development of qualified projects allowed under Government Code Section 66411.7 while ensuring that the new dwelling unit(s) are consistent with Mill Valley development and do not create any significant impacts with regards to public infrastructure or public safety.
B. 
It is the intent of these regulations to provide opportunities for up to four units on two legal parcels in the RS and RP zoning districts by way of subdividing an original lot, consistent with state law and local regulations. In the event of an inconsistency between this chapter and Government Code Section 66411.7, Government Code Section 66411.7 shall prevail.
(Ord. 1358, 5/19/2025)
Provided in this chapter are definitions related to urban lot splits.
"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.
"ADU" or "accessory dwelling unit"
shall have the same meaning as set forth in Municipal Code Section 20.08.070(E).
"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 10% 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.
"Dwelling unit"
shall have the same meaning as set forth in Municipal Code Section 20.08.080.
"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.
"JADU" or "junior accessory dwelling unit"
shall have the same meaning as set forth in Municipal Code Section 20.08.070(F).
"Newly created lot"
means both lots created by an urban lot split.
"Objective zoning standards," "objective subdivision standards," and "objective design review standards"
mean standards that involve no personal or subjective judgment by a public official and are uniformly verifiable by reference to an external and uniform benchmark or criterion available and knowable by both the development applicant or proponent and the public official prior to submittal.
"Panhandle"
means the narrow strip of land on a flag lot, typically less than 30 feet in width, that provides access to a public or private road.
"Primary dwelling unit"
means a single family dwelling as defined in Municipal Code Section 20.08.070(A) that is not an accessory dwelling unit.
"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 or more lots or parcels that do not have frontage on a public street.
"Urban lot split" or "urban lot split application"
means a tentative parcel map application for an urban lot split which is intended to subdivide one existing parcel into two parcels, that is submitted pursuant to and consistent with the requirements of this chapter and Government Code Section 66411.7.
(Ord. 1358, 5/19/2025)
A. 
Parcels Not Eligible for an Urban Lot Split. The following parcels are not eligible to submit an urban lot split application under this chapter:
1. 
Any parcel that was established through a prior exercise of a subdivision as provided for in this chapter or Government Code Section 66411.7 (i.e., a prior urban lot split).
2. 
Any parcel proposing to be subdivided that is adjacent to another parcel where either the owner of the parcel proposing to be subdivided or any person acting in concert with said owner has previously subdivided that adjacent parcel using the provisions in this chapter or Government Code Section 66411.7. For the purposes of this chapter, "any person acting in concert" with the owner includes, but is not limited to, an individual or entity operating on behalf of, acting jointly with, or in partnership or another form of cooperative relationship with, the property owner.
3. 
Parcels that are not in a single family residential zone. Single family residential zones include RS and RP zoning districts.
4. 
Parcels located in:
a. 
Wetlands, as defined in the United States Fish and Wildlife Service Manual, Part 660 FW 2 (June 21, 1993);
b. 
A very high fire hazard severity zone, as determined by the State 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 State Department of Forestry and Fire Protection pursuant to Public Resources Code Section 4202. This subparagraph does not apply to sites excluded from the specified hazard zones by a local agency, pursuant to subdivision (b) of Government Code Section 51179, or sites that have adopted fire hazard mitigation measures pursuant to existing building standards or state fire mitigation measures applicable to the development;
c. 
A hazardous waste site that is listed pursuant to Government Code Section 65962.5 or a hazardous waste site designated by the State Department of Toxic Substances Control pursuant to Health and Safety Code Section 25356, unless the State Department of Public Health, State Water Resources Control Board, or State Department of Toxic Substances Control has cleared the site for residential use or residential mixed uses;
d. 
A delineated earthquake fault zone as determined by the State Geologist in any official maps published by the State Geologist, unless the development complies with applicable seismic protection building code standards adopted by the California Building Standards Commission under the California Building Standards Law (Part 2.5 (commencing with Section 18901)) of Division 13 of the Health and Safety Code), and by any local building department under Chapter 12.2 (commencing with Section 8875) of Division 1 of Title 2 of the Government Code;
e. 
A special flood hazard area subject to inundation by the one percent annual chance flood (100-year flood) as determined by the Federal Emergency Management Agency in any official maps published by the Federal Emergency Management Agency, unless either of the following are met: (i) the site has been subject to a letter of map revision prepared by the Federal Emergency Management Agency and issued to the City, or (ii) the site meets Federal Emergency Management Agency requirements necessary to meet minimum flood plain management criteria of the National Flood Insurance Program pursuant to Part 59 (commencing with Section 59.1) and Part 60 (commencing with Section 60.1) of Subchapter B of Chapter I of Title 44 of the Code of Federal Regulations;
f. 
A regulatory floodway as determined by the Federal Emergency Management Agency in any official maps published by the Federal Emergency Management Agency, unless the development has received a no-rise certification in accordance with Section 60.3(d)(3) of Title 44 of the Code of Federal Regulations;
g. 
Lands 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;
h. 
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);
i. 
Lands under conservation easement;
j. 
A historic district or property included on the State Historic Resources Inventory, as defined in Section 5020.1 of the Public Resources Code, or a site that is designated or listed as a historic landmark, historic property or identified on the Historic Overlay Zoning District by the City.
5. 
The proposed urban lot split would require demolition or alteration of any of the following types of housing:
a. 
A dwelling unit that is subject to a recorded covenant, ordinance, or law that restricts rents to moderate, low, or very low incomes;
b. 
A dwelling unit that is subject to any form of rent or price control through a public entity's valid exercise of its police power;
c. 
A dwelling unit that has been occupied by a tenant within three years of the date of the urban lot split application submittal;
d. 
A dwelling unit removed from the rental market under the Ellis Act within the past 15 years from the date of the urban lot split submittal.
B. 
Determination of Legal Eligibility. A voluntary, preliminary research application may be filed with the Planning Department to receive a determination with respect to a parcel's eligibility for an urban lot split. This shall not constitute a lot split application pursuant to Government Code Section 66477.7 or be subject to the timeframes associated with an urban lot split application. A determination of eligibility shall not guarantee approval of the final lot split. Whether provided alone or in connection with an urban lot split application, the City's determination as to the legal eligibility of a site for processing under this chapter and state law related to urban lot splits shall be final and is not appealable.
(Ord. 1358, 5/19/2025)
A. 
Parcel Requirements. A proposed urban lot split application that complies with Government Code Section 66411.7 is subject to the following objective standards. Notwithstanding the foregoing, the following standards shall be waived if they have the effect of physically precluding the development of two dwelling units on either of the resulting parcels or that would result in dwelling units with less than the minimum allowable square footage permitted by state law.
1. 
Subdivision Map Act. Urban lot splits are subject to the Subdivision Map Act (Division 2 (commencing with Section 66410)), except as otherwise expressly provided in Government Code Section 66411.7.
2. 
Number of Lots. The parcel map to subdivide an existing parcel shall result in two parcels.
3. 
Minimum Lot Size. Each newly created lot shall be approximately equal in lot area provided that one parcel shall not be smaller than 40% of the lot area of the original parcel proposed for subdivision. In no instance shall a new parcel be less than 1,200 square feet in lot area.
4. 
Minimum Lot Width. Each newly created lot shall maintain a minimum lot width, as established in Sections 21.08.190 and 21.08.200.
5. 
Lot Lines. The side lines of all lots shall be at right angles to streets or radial to the centerline of curved streets.
6. 
Maximum Number of Dwelling Units. Newly created lots shall include no more than two dwelling units as defined in Government Code Section 66411.7(j)(2).
a. 
Development standards for net new dwelling unit(s) proposed on lots created pursuant to an urban lot split are set forth in Chapters 20.90 and 20.91.
b. 
No new dwelling units may be added to a newly created lot if the parcel already contains two existing dwelling units. If a newly created lot contains more than two existing dwelling units, excess dwelling units shall be relocated, demolished, or otherwise removed prior to approval of a tentative parcel map.
7. 
New Residential Structures. The following fire protection systems are required for new dwelling units and new residential structures:
a. 
Except as provided in Government Code Section 66314(d)(12), new dwelling units shall install fire sprinklers per California Fire Code Section 903. Fire sprinkler system design and installation shall conform to the provisions of the Southern Marin Fire District Standard 401 and National Fire Protection Association Standard(s) 13R or 13D.
b. 
Residential buildings shall be served by a fire hydrant with a minimum flow of 1,000 gallons per minute within 350 feet of the structure (see Section 15.04.120).
8. 
Nonconforming Conditions.
a. 
No setback shall be required for an existing structure.
b. 
Correction of any existing, legal nonconforming zoning condition shall not be required as a condition of approval of an urban lot split application, except as noted in paragraph (A)(8)(c) below.
c. 
An urban lot split shall not create a new nonconforming zoning condition unless that condition is necessary to meet Government Code Section 66411.7(c).
9. 
Access. All parcels shall have access to, provide access to, or adjoin the public right-of-way by means of a private road, a fire access road, or a driveway, that meets the requirements of the California Fire Code. The following items are required for site access:
a. 
Siting and slope of driveways must comply with safety provisions set forth in the California Building and Fire Codes and local standards.
b. 
A 25-foot-wide panhandle (for a flag lot) or a 16-foot ingress/egress easement shall be provided for all newly created lots that do not have direct frontage on a public or private road.
c. 
Prior to receiving a building permit for a structure on the site, emergency access will need to be demonstrated as meeting the requirements of the California Fire Code. All new dwelling units located more than 150 feet from a City right-of-way must be accessible through a path of travel that is accessible for emergency service vehicles by way of an approved fire apparatus access road at least 20 feet in clear width with an approved driving surface capable of supporting the imposed load of fire apparatus weighing at least 45,000 pounds. The access roadway must be serviceable prior to framing residential structures.
d. 
Driveways that provide access to new buildings shall have a minimum width of 16 feet with an approved driving surface capable of supporting the imposed load of a fire apparatus weighing at least 45,000 pounds. Driveways shall have grades of 18% or less, cross slope of eight percent, and a horizontal inside radius of curvature no less than 27 feet.
e. 
Driveways in excess of 150 feet in length shall provide an approved Fire Department turnaround.
f. 
All curb cuts and driveway access shall conform to Standard 210 of the Southern Marin Fire District.
g. 
The urban lot split may not cut off a parcel's access to a public street, alley or public utility easement.
h. 
The urban lot split may not cut off a parcel's access to utility service available immediately prior to the urban lot split.
i. 
The urban lot split application must demonstrate turn around access for emergency vehicle(s).
j. 
Siting of garages and carports are subject to Sections 20.60.075 and 20.60.080.
k. 
Entrance stairways, patios and decks are subject to Section 20.60.070.
10. 
Field Survey and Monuments. A field survey shall be made in conformity with the Land Surveyors Act and survey monuments shall be set in accordance with Chapter 21.14.
11. 
Easements. Easements shall be required for the provision of public services, such as utilities, to each parcel, or shared access to the public right-of-way. Maintenance and access agreements shall be identified for those easement(s) established as part of an urban lot split application and fully executed through recording the documents with the County of Marin prior to the approval of the final parcel map.
12. 
Utilities. Separate utilities shall be provided for each parcel and must satisfy the following requirements:
a. 
All newly created lots shall have a separate lateral connection to the public sewer.
b. 
All on-site improvements to establish utilities on a parcel, including, but not limited to, water main extensions, sewer laterals, hydrants, and utility meters must be serviceable prior to framing residential structures.
c. 
All utilities shall be undergrounded, unless the Planning Director grants a hardship under Section 14.48.060(B) or if in conflict with subsection (A)(13) below.
13. 
Off-Site Improvements. Notwithstanding Government Code Section 66411.1, The City shall not require dedications of rights-of-way or the construction of off-site improvements for the parcel being created as a condition of issuing a parcel map for an urban lot split.
14. 
Water Supply for Emergency Services. The number of fire hydrant(s) required and minimum flow rates shall be determined by Appendix B and Appendix C of the California Fire Code and satisfy the following local regulations set forth in Section 15.04.120:
a. 
A minimum of one fire hydrant that can supply a minimum of 1,000 gallons per minute is required within 350 feet of the front of any dwelling unit.
b. 
A minimum of one fire hydrant that can supply a minimum of 1,000 gallons per minute is required within 100 feet of Fire Department connection.
15. 
Vegetation Management. Property owners are responsible for managing vegetation on newly created lots, including the following.
a. 
Lots located within the Wildland Urban Interface (WUI), as adopted by the City of Mill Valley, shall comply with the vegetation and fuel management requirements adopted by the California Fire Code and as amended in this Code through local amendments.
b. 
A vegetation management plan shall be submitted and approved as part of the urban lot split application. Vegetation management plans shall comply with Southern Marin Fire District Standard 220, including, but not limited to, the following regulations:
i. 
Vegetation spacing shall comply with California Fire Code Section 4906.4.1 and Southern Marin Fire District Standard 220.
ii. 
The applicant shall comply with California Fire Code and Public Resource Code 4291 requirements relating to the clearance of flammable brush and weeds. A minimum clearance of 30 feet from structures and 10 feet from roads and property lines shall be maintained.
iii. 
New trees classified as fire-resistant vegetation shall be permitted provided the tree is planted and maintained so that the tree's drip line at maturity is a minimum of five feet from any combustible structure.
iv. 
A vertical overhead clearance of 13 feet six inches shall be maintained free of obstructions above any roadbed to comply with Title 15 of this Code and California Fire Code Section 503.1.5.3.
B. 
Restrictions. The following restrictions apply to all parcels that have been subdivided or are proposed to be subdivided concurrently with development under the provisions of this chapter:
1. 
The development and use of the dwelling unit(s) shall only be valid and permitted based on the terms established in this chapter.
2. 
The owner shall sign and record an affidavit placing a covenant that will run with each newly created lot to confirm that the owner will reside in one of the dwelling units on either parcel for at least three years from the date of the recordation of the final parcel map. This requirement shall not apply if the applicant is a community land trust or a qualified nonprofit corporation as provided in Sections 402.1 and 214.15 of the Revenue and Taxation Code, or as otherwise required by Government Code Section 66411.7.
3. 
A note on an additional map sheet for the parcel map and a recorded deed restriction in a form approved by the City Attorney's office shall be applied to all newly created parcels indicating that:
a. 
Short-Term Rentals Prohibited. No dwelling unit(s) shall be rented for a period of less than 31 consecutive days.
b. 
The parcel was split using the provisions of this chapter and no further subdivision of the parcels pursuant to this chapter is permitted.
c. 
Neither ADUs nor JADUs shall be constructed on the subdivided parcels if such development would result in more than two units on either parcel.
d. 
Lands shall be limited to residential uses and contain no more than two dwelling units on each parcel.
(Ord. 1358, 5/19/2025)
A. 
Urban Lot Split Applications Subject to Ministerial Review and Approval.
1. 
A tentative parcel map application for an urban lot split application shall be filed with the Planning Department and shall be accompanied by the required fee and all supporting application materials consistent with this chapter and as required by the Planning Department, including, but not limited to:
a. 
Main and supplemental application forms;
b. 
Application checklists;
c. 
Deed and title reports;
d. 
A tentative parcel map including all information and data identified in Sections 21.20.010 through 21.20.040;
e. 
Applicable affidavits and/or deed restriction forms.
2. 
An application for an urban lot split can be submitted concurrently with an application for housing development on one or both newly created lots. See Chapter 20.91 and Government Code Section 65852.21 for development application requirements.
3. 
Development projects submitted concurrently with a tentative parcel map application for an urban lot split will be considered jointly as one application.
4. 
An application for an urban lot split pursuant to this chapter shall be considered ministerially by the Planning Director or designee, as noted in subsection B below. The application shall be approved, denied, or deemed ineligible for an urban lot split within 60 days from the date the City receives a completed application.
5. 
The Planning Director or designee shall ministerially review and approve a tentative parcel map for a qualifying urban lot split and shall not require a public hearing, provided that the submitted application is complete and demonstrates that the proposed project complies with the applicable requirements contained in this chapter and Government Code Section 66411.7.
6. 
Approval of an urban lot split application is a ministerial act and therefore is not subject to the California Environmental Quality Act.
7. 
The urban lot split application is subject to all impact or development fees related to the creation of a new parcel and redevelopment of the parcel unless prohibited under Government Code Section 66511.7.
8. 
No exceptions to objective standards may be requested or granted except as mandated by Government Code Section 66411.7.
9. 
Urban lot split applications are considered a ministerial action of the Planning Director and are not eligible to an appeal, pursuant to Section 20.100.040.
B. 
Ministerial Approval of Final Parcel Map. Within 24 months from the date of Planning Director approving the 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 Chapter 21.24. 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 Planning Director or designee may grant an extension of time not exceeding one year. Failure to file a final parcel map within the original and/or extended time period granted as herein provided shall terminate the application and all proceedings.
1. 
Upon receipt of the Planning Director's approval of the urban lot split application and submittal of a final parcel map application, the City Engineer and City Surveyor shall review the final parcel map application for compliance with this chapter and the Subdivision Map Act.
2. 
Upon compliance, the City Engineer and City Surveyor shall ministerially approve the final parcel map and associated covenants required under City Code and transmit the final parcel map to the County of Marin for recordation. No building permits may be issued until such time as the map has been recorded by the applicant and conformed copies returned to the City Engineer.
3. 
The final parcel map review application is subject to all impact, development review, processing and recordation fees related to the subdivision and final parcel map applications.
C. 
Specific Adverse Impact. Notwithstanding the foregoing, where the Building Official finds that the proposed urban lot split would have a specific, adverse impact on public health and safety as defined and determined in Government Code Section 65589.5, that cannot be feasibly mitigated or avoided, the proposed application shall be denied.
(Ord. 1358, 5/19/2025)
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 Chapter 8.02 of this Code.
B. 
In addition to the enforcement penalties and procedures included in Chapter 8.02 of this Code, 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:
1. 
Where a dwelling unit has been improperly removed or terminated;
2. 
In any civil enforcement action, the City is entitled to recover attorneys' fees and costs from an owner who is determined to have an illegal dwelling unit or is in violation of this chapter; or
3. 
Reversion to acreage identified in the parcel map approved as part of the urban lot split application.
(Ord. 1358, 5/19/2025)