The Subdivision Map Act is a state law governing the division of land for sale, lease, or financing purposes. Under its authority, California’s local agencies regulate and control the design and improvement of subdivisions, to ensure that new developments are consistent with community needs and goals, while simultaneously preventing fraud, protecting purchases, and ensuring adequate public facilities and services.
What is the Subdivision Map Act?
Since its enactment in 1893, the Subdivision Map Act has evolved through various amendments to enhance local governments’ control over divisions of land. Early versions of the Subdivision Map Act focused on the recording of accurate maps, while later versions introduced substantive review requirements and planning commission involvement. (van’t Rood v. County of Santa Clara (2003) 113 Cal.App.4th 549.)
The modern Subdivision Map Act, as enacted in 1974, continues to regulate subdivisions by focusing on orderly community benefit, undue burdens on the public, and protecting individual real estate buyers. (Pacific Palisades Bowl Mobile Estates, LLC v. City of Los Angeles (2012) 55 Cal.4th 783; Kalway v. City of Berkeley (2007) 151 Cal.App.4th 827.)
Today, the Subdivision Map Act has been interpreted as broadly defining “subdivisions” to mean virtually any division of land for the present or future purpose of sale, lease, or financing. (Tarbet v. East Bay Municipal Utility Dist. (2015) 236 Cal.App.4th 348.) The exact definition of “subdivision” is codified in California’s Government Code Section 66424 and states that “subdivision’ means the division, by any subdivider, of any unit or units of improved or unimproved land, or any portion thereof, shown on the latest equalized county assessment roll as a unit or as contiguous units, for the purpose of sale, lease, or financing, whether immediate or future.” (Gov. Code, § 66424.) For purposes of the Subdivision Map Act, property is considered contiguous units even if roads, streets, utility easements, or railroads separate it. (Id.) Additionally, the definition of “subdivisions” applies to condominium projects, community apartment projects, and when converting five or more existing dwelling units into a stock cooperative. (Id.)
The Subdivision Map Act’s main goals are to encourage and facilitate orderly community development, coordinate planning with the established community pattern, and assure proper improvements are made to prevent the area from becoming an undue burden on local taxpayers. (Cox v. City of Oakland (2025) 17 Cal.5th 362.)
Subdivision Map Act: Regulations and Compliance
The Subdivision Map Act vests local governments with the power to regulate and control the design and physical improvements of subdivisions, including properly considering the subdivision’s relation to adjoining land parcels. Thus, the Subdivision Map act prohibits the sale, lease, financing, or improvement of any parcel of real property for which a final map or parcel map is required, unless a map has been recorded. (Save Laurel Way v. City of Redwood City (2017) 14 Cal.App.5th 1005.) Subdividers must design their subdivisions to conform with all applicable general and specific plans and local ordinances. (Santa Clarita Organization etc. v. County of Los Angeles (2024) 105 Cal.App.5th 1143.) Then, local governments must review and approve all proposed subdivisions to control their design for the adjacent landowners, prospective purchasers, and general public’s benefit. (Tower Lane Properties v. City of Los Angeles (2014) 224 Cal.App.4th 262.) Accordingly, local agencies must disapprove maps that fail to meet all requirements or conditions imposed by the Subdivision Map Act or local ordinances, absent waiver of certain requirements in cases involving technical and inadvertent errors. (Gov. Code., § 66473.)
How Do You Apply?
There are two application process to subdivide property under the Subdivision Map Act: The Tentative and Final Map process for subdivisions creating five or more parcels, and the Parcel Map process for subdivisions creating four or fewer parcels.
The Tentative and Final Map Process
The tentative and final map process is required for subdivisions creating five or more parcels. Under Government Code Section 66426, applicants must prepare a tentative and final map that the local agency must approve before the subdivision can proceed. (Gov. Code, § 66426.) The tentative and final map process involve extensive review and consideration of several factors, including the property’s suitability for development, the adequacy of infrastructure such as roads and sewers, and preservation of natural resources. (Gardner v. County of Sonoma (2003) 29 Cal.4th 990.) Final maps must be recorded with the county recorder to legitimize the subdivision and allow for the parcels’ sale, lease or financing. (Witt Home Ranch, Inc. v. County of Sonoma (2008) 165 Cal.App.4th 543.)
The Parcel Map Process
A parcel map is typically required for subdivisions creating four or fewer parcels. Under Government Code Section 66428, parcel maps must be prepared and approved by the local agency. (Gov. Code, § 66428.) The parcel map must be recorded with the county recorder to allow for legal transactions involving the subdivided parcels. (Gov. Code., § 66499.30.) The parcel map process is overall less rigorous than the tentative and final map process but nonetheless requires compliance with all applicable local and state regulations to ensure proper development and infrastructure.
Unlike tentative and final parcel maps, local ordinances may waive the parcel map requirement under certain conditions. (Gomes v. County of Mendocino (1995) 37 Cal.App.4th 997.) Obtaining a parcel map waiver requires a finding by the legislative body or advisory agency that the proposed subdivision meets all requirements established by the Subdivision Map Act and local ordinances regarding area, improvement and design, floodwater drainage control, appropriate improved public roads, sanitary disposal facilities, water supply availability, and environmental protection. (Gov. Code, § 66428.) Local ordinances may also provide procedures for waiving requirements for a tentative and final map when constructing a condominium project on a single parcel. (Gov. Code, § 66428.)
Similarly, the Subdivision Map Act provides specific statutory exemptions where a parcel map is not required. These exemptions include subdivisions of portions of the operating right-of-way of a railroad corporation created by short-term leases, and land conveyed to or from government agencies, public entities, public utilities, or a subsidiary of a public utility for conveyance to that public utility for rights-of-way unless substantial evidence shows that public policy mandates a parcel map. (Gov. Code, § 66428.)
Impact of Partition Law on Subdivisions
Partition Law intersects with the Subdivision Map Act when a judicial partition of property creates new parcels. Under Government Code Section 66411.5, when a parcel map or final map is required to effectuate a judicial partition, the local agency approving the map can establish monetary exactions or improvement requirements but must defer payment and acceptance until the termination or cancellation of any relevant contract. (Gov. Code, § 66411.5.) Requiring local agencies to defer payment and acceptance ensures the partition process complies with the Subdivision Map Act without imposing an immediate financial burden on the involved parties.
What is an Example?
“Shawn” and “Julie” are co-owners of real property in Southern California. Five years ago, Shawn and Julie purchased a residentially zoned property with six acres of land as co-owners, with plans to rent the property out for profit. Recently, Shawn and Julie have been unable to agree on the property’s future, leading to a falling out over the property’s management. Shawn wants to sell the entire property and cash out, while Julie wants to keep her interest in the land and develop her half independently. For months, Shawn has refused to negotiate with Julie, so, Julie files a lawsuit seeking to partition the property.
Upon reviewing Julie’s application, the court determines partition by physically dividing the land between Shawn and Julie is possible without significant losses in value. So, the court appoints a referee to oversee the partition. The referee then hires a surveyor to divide the land into two equal value lots based on size, access, and zoning, to ensure the relevant Subdivision Map Act requirements are met. Eventually, the court approves the proposed division and grants Shawn and Julie sole ownership of their respective portions. Now, Shawn can sell his newly deeded lot and cash out, while Julie proceeds with her independent development plans.
Conclusion
If you’re considering dividing real property through a subdivision, we may be able to help. If you want to divide your property through partition, we can help. At Underwood Law, our partition attorneys can help you navigate your partition action efficiently and with care. We are here to help.
