News & Insights

Among the most heralded and controversial new laws to come out of the 2021 California legislative session were Senate Bills 9 and 10. SB 9, which allows for “urban lot splits” and the construction of duplexes in single-family neighborhoods, and SB 10, which authorizes local governments to rezone certain residential parcels for greater density, have been hailed by housing advocates and decried by homeowner groups as the end of single-family zoning in California.

Pro-housing groups see these bills as important steps towards dismantling exclusionary zoning laws that have fueled California’s housing affordability crisis by restricting density in some of the state’s most job and transit-rich communities. Homeowner groups and slow-growth advocates see the bills as undue state intrusions on local control and a threat to quality of life in longstanding communities.

The reality is that these bills have received outsized attention relative to the practical impact they are likely to have on California neighborhoods. The bills, while symbolic victories for the pro-housing movement, were heavily negotiated in the Legislature, resulting in diluted final products with limited potential to significantly increase density in single-family zones.

SB 9 allows property owners in urban neighborhoods zoned for single-family homes to subdivide their lots into two separate parcels. Up to two units may then be constructed on each of the resulting new lots, allowing for up to four homes on property that previously accommodated just one. In theory, the process provided for by SB 9 has the potential to significantly increase residential density in urban areas currently reserved for single-family use, an increase that could be especially pronounced when combined with the densification allowed by new state laws regarding accessory dwelling units.

A less publicized feature of the bill requires any property owner undertaking an SB 9 urban lot split to sign an affidavit stating their intent to occupy one of the resulting units as a principal place of residence for at least three years. Other provisions prohibit any lot subdivided under SB 9 from being further subdivided and prevent any property owner who has split a lot under SB 9, or anyone “acting in concert” with such an owner from subdividing an adjacent lot. These provisions effectively prohibit professional developers and real estate investors from taking advantage of SB 9. Only individual homeowners who intend to remain in occupancy may undertake the type of projects envisioned by the bill. These restrictions, inserted in response to the concerns of homeowner groups, will severely curtail the practical impact of SB 9.

While SB 9 removes legal barriers to the densification of single-family neighborhoods, individual homeowners who are not professional developers or real estate investors are far less likely to pursue the costly and time-consuming subdivision and construction processes required to take advantage of the bill. A limited number of enterprising homeowners may well be up for the task, but the exclusion of developers and investors from SB 9’s protections means that single-family neighborhoods are unlikely to be transformed overnight.

SB 10 has similarly generated controversy disproportionate to its likely impact. The bill permits (but does not require) a local government to enact an ordinance to rezone certain urban parcels close to transit to allow up to 10 residential units per lot without environmental review under the California Environmental Quality Act. Unlike many recent state housing laws, which reduce local control over land use decisions, SB 10 leaves discretion with local governments, who may opt out of taking any action under the bill. Local politicians with anti-development constituencies are highly unlikely to support densification under SB 10 when the bill allows them to simply opt out.

While SB 10 may help pave the way for additional density in cities already inclined to support more housing, it is unlikely to have an impact in places where decisionmakers and their voters are wary of densification. Additionally, the bill provides a CEQA exemption for ordinances to allow greater density but does not provide a corresponding exemption for the housing development projects that could result on re-zoned parcels, which could consequentially still be held up by environmental litigation in cities that do opt to rezone land under SB 10.

Although SB 9 and 10 provide roadmaps for the addition of more residential density in urban areas zoned for single-family homes, exceptions and limitations in the bills are likely to restrict their practical impact. While one could argue that these bills technically end single-family zoning in California, they are unlikely to significantly change the form or character of most single-family neighborhoods, absent future revisions.

An associate attorney with the Los Angeles office of Crosbie Gliner Schiffman Southard & Swanson LLP (CGS3), Lee Kaplan specializes in commercial real estate law. He has extensive transactional experience as well as broad expertise in land use and environmental law. The article can also be read in the Daily Journal and in the Daily Transcript (subscription required).