The New SB9 Explained

The Law – SB 9

Senate Bill 9, also called the California Housing Opportunity and More Efficiency (“HOME”) Act, was signed into law on September 16, 2021. The so-called “duplex bill” is part of an initiative to address California’s housing crisis. SB 9 provides a legal, streamlined process for homeowners to subdivide their urban single-family residential lot and/or build additional residential units on their property.

Specifically, SB 9 alters the municipal review process for two-unit housing developments on single-family lots and for the subdivision of property. Where the review process used to be discretionary (subjective, case-by-case), it is now subject to ministerial approval (objective, consistently applied). This change will ideally simplify and expedite the permitting process, making it easier and more accessible for homeowners to build additional housing on their property.

Senate Bill 9 goes into effect statewide on January 1, 2022 and all California cities must comply. However, local governments are allowed to impose their own objective design standards and limitations, as long as they don’t directly conflict with the state law. These regional ordinances on SB 9 will likely evolve throughout early 2022.

Context: The Housing Crisis

California is confronting a shortage of affordable housing—particularly in urban areas like Los Angeles—which is increasing rental burden and driving displacement throughout the state. It is estimated that California will need 3.5 million additional units of housing by 2025 to meet the demand; however, fewer than 80,000 new homes are currently built per year.

State legislation passed in 2017 legalized the building of accessory dwelling units in all California cities, regardless of zoning. The resulting ADU boom has helped increase the number of new housing units built over the past few years. And yet, it’s still nowhere near enough.

One of the greatest challenges facing housing construction is the predominance of single-family zoning, which allows only one house per lot. Almost 66% of all California residences are single-family housing and nearly 75% of all developable land is zoned single-family. This severely limits the types of housing that can be built and pushes the boundaries of urban expansion ever outward.

Some argue that single-family zoning is intrinsically linked with the “California Dream” of owning a family home with a big private backyard. However, due to soaring housing costs in a highly competitive market, that dream is far out of reach for a growing number of Californians.

Aside from limiting accessibility, the single-family model no longer serves the needs of our modern lifestyle. Multigenerational households, communal living, and the rise of remote work are transforming the ways we live together in cities. It’s time for our zoning rules to reflect this change.

What Can I Build? – SB 9

All single-family property owners are eligible under SB 9 to build a second unit within their existing lot. This provision is a great option for homeowners looking to build additional housing for their extended family. It’s also beneficial for rental-property owners who want to add a second long-term rental unit. Single-family property owners can also utilize SB 9 to subdivide their property into two lots.

However, homeowners who split their property must commit to occupying one of the lots as their primary residence for a minimum of three years. Once the lot is split, homeowners have a wide variety of options for developing housing on their newly created lots. These possibilities include single-family dwellings, duplexes, and ADUs.SB 9 entitles homeowners to build one duplex and, depending on local ordinance, up to two ADUs on each lot. This allows for a maximum total of 8 units across the two lots