The Step-by-Step Process for an SB9 Lot Split

Last reviewed May 2026

Successfully completing a lot split under California's SB 9 law is a detailed, multi-phase process that requires careful planning, coordination, and professional management. Riechers Engineering guides clients through every step, from the initial eligibility check to the final recording of the new parcels.

If you are still getting oriented, start with our California SB9 lot split guide. This page focuses on the process itself: what happens after a property appears to qualify and the owner wants to move toward an actual parcel map.

Start With SB9 Eligibility

The first step is confirming whether the property is a realistic SB9 candidate. A qualifying property is typically in a single-family residential zone, located in an urbanized area or urban cluster, and not excluded by tenant protections, historic-resource rules, prior SB9 lot split limits, or certain environmental and hazard constraints.

Eligibility is not just a yes-or-no legal question. Access, frontage, utilities, easements, slope, drainage, existing structures, local objective standards, and the likely building envelope on each future lot can all affect whether the split is feasible.

Phase 1: Tentative Parcel Map Approval

The first major phase is the Tentative Parcel Map, often called the TPM. This phase focuses on preparing, submitting, managing, and obtaining approval for the proposed subdivision. The goal is to show that the lot split complies with SB9, the Subdivision Map Act, and city or county requirements.

1. Full eligibility assessment

Riechers Engineering reviews the property, zoning, local ordinances, site conditions, and likely constraints before moving deeper into the application. This helps avoid spending serious money on a layout that cannot be approved or recorded.

2. Affidavit and application documents

The application package may require owner affidavits, jurisdiction-specific forms, and supporting exhibits. We prepare the required documents for the local agency and confirm what needs to be included before submittal.

3. Title guarantee and property document review

A title guarantee and related property documents help verify ownership and identify easements, restrictions, recorded conditions, and other items that may affect the proposed split.

4. Evidence B-K documentation

Many SB9 applications require supporting documentation to demonstrate eligibility. We assemble the required evidence so the reviewing agency can evaluate the file against the statute and local standards.

5. Submittal requirements, fees, and lot layout

Each city or county may have its own submittal checklist and fee schedule. We identify those requirements, help finalize the proposed lot layout, and confirm that the map direction makes practical sense before drafting begins.

6. Tentative parcel map drafting

The tentative map is drafted to show the proposed new parcel configuration and the technical information required by the reviewing agency.

7. Application, map submittal, and fee payment

Once the application and tentative map package are complete, the package is submitted to the planning department and required city or county fees are paid to keep the review moving.

8. Comment response, resubmittals, and expediting

Agency comments, incompleteness reviews, and resubmittal requests are common. Riechers Engineering manages the response process, updates documents, resubmits quickly, and advocates for approval.

9. Environmental coordination when needed

Some properties require biological assessments, wetland assessments, or other environmental documentation. Those items are coordinated when they are required by the site or agency.

10. Client communication and monthly status updates

SB9 projects can involve long agency review cycles. We provide project status updates and remain available for client questions so the owner understands what is happening and what comes next.

Phase 2: Final Parcel Map and Recording

After tentative approval, the project moves into the Final Parcel Map phase. This is the formal legal and technical step that turns the approved concept into recorded parcels.

1. Topographic and boundary surveys

Detailed survey work is completed so the final map can accurately show boundaries, site conditions, and required mapping information.

2. Reference document collection and certificate sheet setup

Reference materials are collected and the certificate sheet is outlined so the final map package can be prepared correctly for review.

3. Final parcel map preparation

The final map is prepared for city and county review. This phase often requires close coordination between survey, engineering, title, utility, and agency requirements.

4. Final map package submittal and project management

The final map documents are compiled, submitted, and managed through review. This phase commonly takes several months depending on the city or county and the complexity of the site.

5. Utility coordination

Where required, utility providers may need to issue will-serve letters or otherwise confirm service availability for the resulting parcels.

6. Engineering plans and easements when needed

Some projects require drainage plans, erosion control plans, improvement plans, access easements, utility easements, or drainage easements before the final map can be approved.

7. Tax, assessor, title, and recording coordination

Before recording, the project may require tax collector coordination, property tax payment prompts based on assessor figures, assessor processing fees, title company processing fees, owner signatures, notarization, agency signatures, and final recording fees.

8. Mylar signing and final recording

The mylar copy of the map is ordered, owner signatures are notarized, city signatures are obtained, and the approved final parcel map is recorded. Once recorded, the new legal parcels are established.

How Long the SB9 Lot Split Process Can Take

State law creates ministerial review requirements, but real-world timing still depends on application completeness, agency review cycles, survey work, title conditions, utilities, and technical issues. As a practical planning range, the tentative map phase can take roughly 3 to 8 months, and the final map phase can take roughly 5 to 10 months depending on the jurisdiction and site complexity.

The fastest projects tend to have clean eligibility, a practical lot layout, clear access, manageable utilities, and a complete application package. Projects slow down when there are easement conflicts, access issues, drainage questions, incomplete submittals, or agency comment cycles that are not managed aggressively.

Why Project Management Matters

An SB9 lot split involves dozens of steps, multiple agencies, and precise compliance with technical standards. Missing a small detail or deadline can cause months of delay or jeopardize the project.

Riechers Engineering provides comprehensive project management so homeowners can move through the process efficiently, confidently, and successfully. Our team understands what cities and counties are looking for and how to keep projects moving forward.

Interested in starting an SB9 lot split?
Contact Riechers Engineering for a free SB9 eligibility check and personalized report.

Related SB9 Guides

SB9 Lot Split Process FAQs

What are the main phases of an SB9 lot split?

Most SB9 lot split projects move through an eligibility review, tentative parcel map preparation and approval, final parcel map preparation, technical coordination, signatures, and final recording.

Does SB9 approval happen automatically?

No. SB9 can require ministerial approval when a project meets the statute and applicable objective standards, but the applicant still needs a complete and accurate application package.

Can a city or county deny an SB9 lot split?

A local agency may deny a qualifying SB9 application only under limited circumstances, including a specific adverse impact on public health and safety or the physical environment that cannot be mitigated, or if the project fails applicable statutory requirements.

Do I need a tentative parcel map and a final parcel map?

In many SB9 lot split projects, yes. The tentative map phase establishes the proposed split for review and approval, while the final map phase creates the recordable legal document.

Who should manage an SB9 lot split?

An SB9 lot split is typically managed by professionals who understand surveying, civil engineering, mapping, title review, jurisdictional submittals, and agency coordination.

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