California’s affordable housing shortage has reached a dire point. Over 3.2 million residents are rent burdened, and only 16% are able to afford to buy a home. This unsustainable crisis has put extreme pressure on the government to provide solutions, prompting the introduction of several recent state bills. 

In September 2021, Governor Gavin Newsom signed the SB9 “Duplex Bill” into law, giving homeowners the power to become developers and turn their properties into higher-density, income-generating rentals. Below, we answer the question of “What is SB9?” and discuss how Design-Build services can help homeowners make the most of this new zoning rule. 

SB9 Expands Housing Options for Single-Family Lots

California Senate Bills (SB) 8, 9, and 10 were introduced to encourage new home construction, increase residential density, and expand city zoning options for multi-family residences. The goal is for these bills to spark production of new and affordable homes, of which California needs at least 180,000 per year. 

SB8 was created to simplify the approvals process for housing development projects, while SB10 makes it easier for cities to upzone property for housing (especially near transit or urban infill areas). 

SB9, however, directly benefits homeowners, allowing them to:

1. Divide their property into two lots
2. Build a home + an ADU on each of these new lots

This effectively legalizes the construction of fourplexes in areas where only a single home was permitted. Homeowners have the opportunity to increase their property values and generate new tenant income, all while maintaining residency on their property. Their projects will not be bogged down by discretionary reviews or hearings, and can only be struck down if the city finds a tangible threat to public health and safety. 

The community benefits by seeing increased and diversified housing availability, new opportunities for renters, and more efficient use of land in residential zones. Such perks are invaluable at a time when availability of rentals are at their lowest, modest housing options are scarce, and neighborhoods are working to contain urban sprawl. 

January 1st, 2022 saw SB9 go into effect. Since that time, many homeowners, especially in Los Angeles and San Diego, have inquired about modifying their lots according to the new rules, or already submitted applications for their projects. 

Does My Lot Qualify for SB9?

If you’re interested in building duplexes on your lot under SB9, the good news is that it’s fairly easy for the average residential property to meet the requirements. The property must: 

• Be located within a single-family residential zone
• Be located within a city containing urbanized areas, or within the boundaries of an urbanized area/urban cluster if located within an unincorporated area
• NOT be located in a historic or landmark district
• NOT be subject to rent control
• NOT be located within the presence of farmland, wetlands, fire hazard areas, earthquake hazard areas, flood risk areas, conservation areas, wildlife habitat areas, or conservation easements

SB9 Project Requirements

Should your lot meet the requirements for SB9, bear in mind that there are rules that also apply to the subsequent construction project. 

• Original lot can only be divided once, into two parcels
• Each new parcel may not be smaller than 40% of the original lot size
• Each parcel must be at least 1,200 square feet in size (unless permitted by local ordinance)
• Each new primary unit must be at least 800 square feet in size
• Up to 2 units per lot are permitted when lot is split (with ADUs counting toward this limit)
• In cases when the lot is not split, one ADU is permitted, as well as one JADU if local rules allow
• No more than 25% of existing structural walls may be demolished (exceptions for local ordinance permissions)
• Demolition or alteration is only permitted for housing that has NOT been tenant occupied within the last 3 years
• Applicants must intend to use one of the units as their main residence for at least 3 years after approval

Still not sure if your lot or project is eligible under SB9? Then it’s best to reach out to your local planning department, or get the advice of a specialized Design-Build firm, such as Letter Four. 

How Letter Four Can Help California’s Homeowners

Homeowners who are hoping to take advantage of SB9 are best served by a firm that is capable of addressing all of the unique aspects of this type of project. As a Design-Build firm, Letter Four offers the full scope of services necessary to assess lot suitability, design efficient and compliant units, and complete the build with quality craftsmanship. 

The entire project is managed by a single team, making it easier to get your SB9 conversion finished faster, and at a greater value. Your risks are reduced significantly, giving peace of mind that what could be a complicated project stays well organized and on-budget. 

Our team has the expertise necessary to navigate the planning and permitting requirements for this new zoning change. We have already helped some of Southern California’s first homeowners with their own SB9 projects, creating stunning new housing units full of opportunity. We’re ready to do the same for you. You can review our Project Action Plans to learn more about how to get started, or contact us today to schedule a consultation.