SB 9 In Palo Alto: What Owners Should Know

Thinking about splitting your Palo Alto lot or adding a second home on your property? SB 9 opened a new path for small-scale development, but the rules can feel complex fast. You want clarity on what is allowed, what might block a project, and how to move forward without surprises. This guide breaks down SB 9 in plain language, explains how it typically works in Palo Alto, and gives you a practical checklist to evaluate your options. Let’s dive in.

SB 9 in plain English

SB 9 is a California law that offers two ministerial tools for single-family parcels:

• Urban lot split: You may be able to split one qualifying single-family lot into two separate legal lots.
• Duplex approval: You may be able to build up to two units on a qualifying single-family lot.

When combined, an original parcel can become two lots with up to two homes on each, for a maximum of four units total. Approvals are typically ministerial when your plans meet state law and objective local standards. That means no public hearings and a more predictable process.

SB 9 was designed to add gentle density while respecting neighborhood form. It also includes protections and exemptions. Parcels tied to certain historic resources, environmental constraints, or legal restrictions may not qualify. Local governments can apply objective standards such as height, setbacks, and lot coverage, and can deny projects that fall under specific exemptions.

What this means in Palo Alto

Palo Alto follows state law while applying its own objective standards. In practice, that means your project must fit clear numeric rules and documented criteria. A few local considerations often shape feasibility:

• Zoning and lot size: Confirm your parcel is in a single-family zone and review any minimum lot size or dimension standards for splits.
• Tree protections: Palo Alto regulates tree removal. Significant trees can limit building locations or require mitigation.
• Historic status: Homes with historic designation or within certain districts may be ineligible.
• Objective design: Expect numeric limits on height, setbacks, lot coverage, and open space that can shape how many units fit.
• Parking and transit: Parking requirements may change near transit under state rules. Confirm how Palo Alto applies this.
• Utilities and infrastructure: Plan for sewer, water, stormwater, and potential upgrades.
• Slopes and geotechnical: Slope, fill, or hazard zones can add studies, costs, or disqualify a site.
• CC&Rs and HOAs: Private covenants can restrict splits or additional units even if the city allows them.
• Financing and insurance: Lenders and title insurers may have special requirements for lot splits or new multi-unit configurations.

For parcel-specific standards and procedures, contact the City of Palo Alto Planning Division and review the municipal code and any SB 9 application materials. For recording steps and parcel history, consult the Santa Clara County Recorder and Assessor.

Quick eligibility check

Use this early filter before you hire consultants:

• Zoning: Is the property a single-family parcel that could qualify under SB 9?
• Restrictions: Any historic designation, conservation easement, or recorded limitation that prohibits a split or extra units?
• Site conditions: Regulated trees, steep slopes, known hazards, or environmental constraints?
• Lot feasibility: Will objective setbacks, height, coverage, and open space allow two units per lot if you split?
• Private rules: Any CC&Rs or HOA provisions that limit subdivision or added units?
• Utilities: Is the site served by public sewer and water, and will capacity support additional units?

Quick wins to look for

• A straightforward single-family parcel with no historic designation.
• A lot size and shape that can meet numeric setbacks and coverage with room for two units.
• Flat topography and minimal regulated trees.
• Existing public utilities at the frontage with clear paths for new connections.

Common deal stoppers

• Historic designation or location within a protected district.
• Recorded easements or conservation restrictions that limit buildable area or subdivision.
• Significant regulated trees where removal or relocation is not feasible.
• Slope or geotechnical hazards that drive up costs or block approvals.
• CC&Rs that prohibit additional units or subdivision.

The SB 9 process in Palo Alto

While every parcel is different, most owners follow a similar path:

1. Preliminary eligibility check

• Confirm zoning and basic parcel eligibility under SB 9 and Palo Alto’s objective standards.
• Identify constraints: historic status, easements, trees, slopes, flood or hazard zones.

2. Pre-application or planning intake

• Meet with City Planning to clarify which objective standards will apply.
• Discuss setbacks, height, lot coverage, parking, and how ADU rules interact with SB 9 units.

3. Prepare application materials

• Owner affidavit if required.
• Site survey, preliminary site plan, and title documents.
• Any environmental or special studies required by objective standards.

4. Ministerial review

• City staff verifies compliance with state and local objective rules.
• If compliant, staff issues ministerial approvals. Approvals are usually recorded with the county.

5. Building permits and construction

• Submit detailed building plans for plan check.
• Coordinate utility connections and inspections during construction.

6. Recording and final steps

• Record deeds for new lots if you complete a split.
• Record any required easements or deed restrictions.

Costs and timeline basics

• Timing: Ministerial planning reviews often take weeks to a few months, depending on completeness and city workload. Building permits and construction can add several months to over a year.
• Fees: Expect plan-check and building permit fees, plus utility connection or capacity charges. Impact and mitigation fees may apply.
• Construction: Budget for unit build costs and site work such as utilities and access. Costs vary by design, finish level, and market conditions.
• Taxes and financing: A split and new units can change assessments. Discuss lending, title insurance, and any payoff or subdivision-related requirements early.

ADUs and SB 9

Accessory dwelling unit rules are a separate track under state law. They can interact with SB 9 outcomes in complex ways, especially on newly created lots. Confirm with Palo Alto Planning how ADUs or JADUs may be treated alongside SB 9 units on your parcel.

Owner occupancy and neighbor concerns

Some jurisdictions include owner affidavits or similar declarations in SB 9 applications. Confirm Palo Alto’s specific requirements during intake. Because SB 9 approvals are ministerial when objective standards are met, there are typically no public hearings. Neighbors cannot override an eligible project, though they can raise valid issues such as easements or historic constraints that must be resolved.

Your next steps

• Pull parcel data: APN, zoning, and lot size from the County Assessor.
• Review title and CC&Rs for any restrictions on additional units or subdivision.
• Contact City of Palo Alto Planning for an SB 9 pre-application meeting and objective standards checklist.
• Order a site survey and ask an architect or SB 9-experienced contractor for a massing study.
• Check for regulated trees, slope or geotechnical issues, and utility capacity.
• Speak with your lender and title company about financing and title insurance.
• If the site pencils and the standards fit, proceed with your ministerial application and begin planning for building permits.

If you want a seasoned, Peninsula-based perspective on value, risk, and resale strategy before you commit to an SB 9 path, connect with Dana Rae Stone. Let’s talk about your home.

FAQs

Can I split my Palo Alto lot and build a duplex on each new lot?

• SB 9 can allow an urban lot split and up to two units per lot, for a potential total of four units, if your parcel meets state law and Palo Alto’s objective standards and is not subject to exemptions.

How long do SB 9 approvals usually take in Palo Alto?

• Ministerial planning review often takes weeks to a few months depending on completeness and workload, with building permits and construction adding several months to over a year.

Do I need to live on the property to use SB 9 in Palo Alto?

• Jurisdictions sometimes require owner affidavits or declarations; confirm Palo Alto’s specific procedures and any owner-occupancy elements during your planning intake.

Will SB 9 trigger environmental review in Palo Alto?

• SB 9 is structured so qualifying ministerial approvals avoid discretionary environmental review, but parcels with environmental constraints may be ineligible or require additional studies under objective standards.

Can I build ADUs in addition to SB 9 units in Palo Alto?

• ADU rules are separate and can interact with SB 9 in complex ways; verify with Palo Alto Planning how ADUs or JADUs are treated on SB 9 lots before you design your project.