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SB 9 Urban Lot Split Engineering Services
California Senate Bill 9 allows many single-family parcels to be divided into two. We handle the engineering, mapping and agency process that makes it happen.
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- SB 9 Urban Lot Split Engineering — California Licensed
Understanding Senate Bill 9
Senate Bill 9, the California Housing Opportunity and More Efficiency Act, took effect in January 2022. It allows qualifying property owners in single-family zones to divide one parcel into two through an urban lot split, and to add units on the resulting parcels, subject to statutory conditions and local implementation.
The process is ministerial. That means a complete application meeting the objective standards is approved without discretionary hearings, which is substantially faster than a conventional subdivision. It does not mean approval is automatic. Applications fail routinely on survey accuracy, utility service, easements, access, drainage and local objective standards.
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What SB 9 can make possible
- Division of one single-family parcel into two separate legal parcels
- Ministerial review rather than discretionary hearings
- Up to two units on each resulting parcel, subject to local standards
- Creation of a saleable parcel, or additional rental units on the existing property
- A faster path than a traditional tentative and final map subdivision
Where projects actually fail
Most SB 9 applications that stall do so for engineering reasons rather than legal ones. The common causes are:
Parcel size and configuration
Each new parcel must meet the minimum area and the approximately equal division requirement, with usable buildable area after setbacks
Separate utility service
Each parcel generally needs independent water, sewer and power service, which can require main extensions or new laterals
Access and easements
Frontage, driveway access, fire department access and reciprocal easements must be resolved on the map
Drainage
Runoff cannot be redirected onto neighboring parcels; grading and drainage design is usually required
Site constraints
Hillside, flood, fire hazard severity and historic designations can limit or disqualify the parcel
Local objective standards
Each city adopts its own implementing ordinance with its own submittal checklist
Our SB 9 scope
Eligibility screening
Review of zoning, parcel history, exclusions and the local ordinance before you spend money on survey and design.
Survey coordination
Boundary and topographic survey arranged through a licensed land surveyor and integrated into the map.
Parcel map preparation
Tentative and final parcel map documents prepared to the jurisdiction's format and checklist.
Utility and service design
Separate water, sewer, storm and power service layouts coordinated with each purveyor.
Grading and drainage
Site grading, drainage and erosion control where required by the local ordinance.
Application management
Submittal, comment responses and coordination with planning and public works through approval.
What happens after the split
A lot split is the beginning of a development, not the end. Once the map is recorded, most owners move directly into designing the units. Because we also provide structural and MEP engineering, the same team can carry the project from map through building permit without a second consultant learning the site.
- Common Questions
Frequently asked questions
The parcel must be in a single-family residential zone within an urban area, the resulting parcels must each be at least 1,200 square feet and roughly equal in size, and the property must not fall under one of the statutory exclusions. Applicants are also required to sign an affidavit committing to occupy one of the units for three years. Local implementation varies, so eligibility should be confirmed against the specific city or county ordinance.
SB 9 lot splits are processed ministerially, which is faster than a traditional subdivision, but the timeline still depends on the jurisdiction. Three to six months from application to approval is a common range once the survey and engineering are complete.
Costs typically include the city application fee, boundary and topographic survey, civil engineering and mapping, and any required utility or frontage improvements. Fee structures vary widely between jurisdictions, which is why we price each project after reviewing the specific parcel.
SB 9 generally permits up to two units on each resulting parcel, which can allow up to four units on the original property. Local development standards, setbacks and utility capacity will determine what is actually buildable.
No. SB 9 is California law. Nevada and Florida projects follow their own state and local subdivision procedures, which we handle as conventional parcel map or plat work.
This page describes engineering services and general information about California Senate Bill 9. It is not legal advice. Eligibility depends on the specific parcel and the adopted ordinance of the jurisdiction, and should be confirmed before any purchase or development decision.
Send the address and the scope. We will send back a fee.
Every inquiry is reviewed by an engineer. You receive a written scope, fee and schedule, or a direct answer that the work falls outside what we should take on.
2102 Business Center Drive, Suite 130, Irvine, CA 92612