SB-9 Requirements: A Step-by-Step Guide

Step 1: Confirm the parcel is eligible

Before anything else, verify eligibility, because SB-9's by-right approval only protects projects that actually meet the criteria. The parcel must be in a single-family residential zone within an urban area, and it must not fall into an excluded category — historic district, prime farmland, wetlands, or a high fire, flood, or earthquake-fault hazard zone, among others. The law's tenant protections must also clear: SB-9 generally cannot be used to remove housing occupied by a tenant in the last three years, rent-controlled housing, or recently Ellis Act-withdrawn units.

We cover this screen in depth in our companion guide on SB-9 lot-split eligibility. Pull your parcel's zoning and hazard maps and the city's adopted SB-9 standards before spending on design. Getting eligibility right at Step 1 is what makes every later step predictable; getting it wrong means a denial the by-right pathway cannot fix.

Step 2: Choose your pathway — two units, lot split, or both

SB-9 actually grants two separate rights, and you can use one or both. The two-unit pathway lets you build up to two units on a single-family parcel — for example, adding a second home, or replacing one house with a duplex. The urban lot split lets you divide the parcel into two lots. Combine them and a single original lot can support up to four units, two on each new parcel.

The combination is where SB-9's density potential is highest, but it also stacks the requirements: the lot split carries an owner-occupancy affidavit (intent to live in one unit for at least three years) that the two-unit path alone does not. Decide early which combination fits your goals, your budget, and — if you are an investor rather than an owner-occupant — whether the affidavit is workable. The pathway you choose shapes the application, the standards, and the financing. If part of your plan is an accessory unit, our guide on how to build an ADU covers that adjacent track.

Step 3: Prepare and submit the application

With eligibility confirmed and a pathway chosen, you prepare the application package. For construction, that means plans and drawings showing the proposed units, the site layout, and how the project meets the city's objective standards; for a lot split, it means a tentative or parcel map prepared to the jurisdiction's specifications, plus the required owner-occupancy affidavit. Because SB-9 review is objective rather than discretionary, the package should demonstrate compliance with measurable standards — setbacks, unit size, height — rather than argue the project's merits.

Submit the package to the local planning or building department, increasingly through an online portal, and pay the applicable fees. Many cities have an SB-9-specific application or checklist; using it reduces back-and-forth. The cleaner and more complete your submittal, the faster it clears — incomplete applications are the most common cause of delay even in a ministerial process. For the general mechanics of permit submittal and plan review, our ADU permit guide and building-permit guide walk through what to expect.

Step 4: Ministerial review and the decision deadline

SB-9 approval is ministerial, meaning the city checks the application against objective standards and approves it if it complies — no public hearing, no discretionary judgment, and no CEQA review for qualifying projects. This predictability is the whole point: you are not asking permission so much as demonstrating compliance.

Later amendments to SB-9 added a decision deadline. In general, the local agency must approve or deny a complete SB-9 application within 60 days, and a denial must rest on objective public-health-or-safety grounds rather than vague or aesthetic objections. If the city does not act within the window, the application can be deemed approved. The practical takeaway is to submit a complete, standards-compliant package and track the clock, because the law is designed to move these projects quickly once they are properly filed. (Timelines and standards have changed through amendment and litigation — confirm the current rule locally.)

Step 5: Build to SB-9 standards

Approval comes with build standards a city must allow, which protect the project from being regulated out of existence. A jurisdiction generally cannot impose objective standards that would physically preclude two units of at least 800 square feet each, and setback requirements are capped — typically no setback for an existing structure kept in place, and up to four-foot side and rear setbacks otherwise. Parking is limited to no more than one space per unit, and none can be required when the parcel is within a half-mile of high-quality transit or a major transit stop, or has car-share nearby.

From there, construction follows the normal arc: build to the approved plans and pass inspections through to final sign-off. Units must be used residentially, and homes on a lot-split parcel cannot be rented as short-term rentals under 30 days. To see where SB-9 projects are actually being built and to target eligible activity, explore California permit data, drill into a market like Los Angeles permit activity, or request access to Igni's feed, which flags SB-9 signals. (General information only — not legal advice.)

Frequently asked questions