FAQs About Two Unit Development SB 9

What is SB 9 and how does it apply to two unit development?

SB 9 is a California law that lets homeowners build two housing units on a single‑family zoned lot or split that lot into two parcels to build units on each. It applies only in areas zoned for single‑family homes and streamlines approvals through objective ministerial review. This means cities must approve qualifying projects without discretionary hearings.

Who is eligible to use SB 9 for a two unit project?

To qualify, your property must be in a single‑family zone and not in restricted areas like flood plains, wetlands, historic districts, or high fire hazard zones. It must also have access to utilities and a public right‑of‑way. Projects demolishing affordable or rent‑controlled housing may be excluded. Always check with your local planning department.

Can I split my lot under SB 9 and build on each parcel?

Yes. SB 9 lets you perform an urban lot split to divide a single‑family lot into two separate parcels. Each new parcel must be roughly equal in size (at least 40 % of the original) and meet minimum area requirements (often 1,200 sq ft). Once split, each lot may have up to two units under SB 9 rules. Association of Bay Area Governments

Do I have to live on the property to use SB 9?

If you are proposing an SB 9 lot split, you must sign an affidavit stating you intend to live in one of the units for at least three years. This requirement does not always apply if you are only building an additional unit without splitting the lot. Always check local ordinances for specifics. Oceanside CA

Can I rent out the units created under SB 9?

Yes, you can rent SB 9 units. However:

• Short‑term rentals (less than 30 days) are generally prohibited by state law.

• Long‑term rentals (30 days or more) are allowed.

You must still follow local rental regulations and safety standards. Petaluma

How many units can be built under SB 9 on one lot?

SB 9 typically allows:

• Two primary units on a single lot, or

• After a lot split, two units per new parcel (up to four total).

Accessory dwelling units (ADUs) and junior ADUs may also be allowed depending on local rules. Westwood Homeowners Association

Do I need a public hearing for an SB 9 project?

No. SB 9 projects are reviewed ministerially, meaning:

• No public hearings are required.

• No subjective review by planning boards.

This helps speed up approvals as long as objective standards are met.

Can an HOA block my SB 9 project?

Homeowners associations (HOAs) may have covenants or restrictions that conflict with SB 9. Some local ordinances allow HOAs to enforce their rules, while others do not. You should review CC&Rs and consult with a planner or attorney before proceeding.

What standards must SB 9 units meet in terms of design?

SB 9 units must comply with objective standards such as:

• Minimum unit size and height limits

• Setbacks (often 4 ft from side/rear)

• Local design standards that are objective

Cities can add objective rules but cannot impose subjective requirements.

How long does the SB 9 approval process take?

While times vary by city, many jurisdictions aim to complete ministerial review within 30–60 days of a complete application for completeness and eligibility. This is typically quicker than traditional discretionary reviews. Always check local timelines. Milpitas

Can I build an ADU with my SB 9 units?

Yes, in many cases you may add ADUs or junior ADUs (JADUs) in addition to SB 9 units, depending on local rules. Some cities restrict ADUs on split lots, while others allow them above duplexes or alongside primary units. Confirm with your planner.

What happens if my property is in a high fire zone?

Properties in Very High Fire Hazard Severity Zones or other restricted areas may be excluded from SB 9 or require additional safety conditions. Local fire safety measures may apply before approval. Moraga

Can I combine SB 9 and traditional subdivision laws?

No. SB 9 urban lot splits are a one‑time subdivision method under state law. They don’t require full subdivision approvals, but must still comply with state and local standards like the Subdivision Map Act.

Does SB 9 override local zoning rules?

Not completely. SB 9 overrides certain zoning limits on unit count, but local objective standards for setbacks, parking, and design still apply. Local planning codes must allow SB 9 projects that meet objective criteria.

Can I demolish an existing home under SB 9?

You can demolish the existing home to build new units, but there are limits:

• Demolition of housing with rent‑controlled tenants or affordable restrictions may disqualify ministerial approval.

Check with your planner before planning demolition. City of Gilroy

Is neighbor notification required for SB 9 projects?

No. Under SB 9, neighbor notification is generally not required for ministerial review. This helps reduce delays and controversy over new units. However, some cities may still enforce neighborhood notification for other reasons.

Can SB 9 projects be sold separately?

Yes, if you complete an urban lot split and create two parcels, each parcel can be sold independently. This can increase flexibility and investment opportunities.

Are there parking requirements for SB 9 units?

Many cities require one parking space per unit. However, if the property is within 1/2 mile of a transit corridor or major stop, parking requirements may be waived. Always confirm with local guidelines.

Can I do more than one SB 9 lot split on the same property?

No. SB 9 allows only a one‑time lot split for each original property. You cannot split again under SB 9 after the initial division. Oceanside CA

What zoning types do SB 9 rules apply to?

SB 9 applies only to single‑family residential zones (R‑1) or equivalent. It generally does not apply to multifamily zones like R‑2, R‑3, or commercial zoning.