Can you split your lot and build more homes?

First: it is SB 9, not “Section 9”

California Senate Bill 9 established ministerial paths for qualifying projects. One path addresses up to two primary units on an eligible parcel; another addresses an urban lot split. How the paths interact, plus ADU rules and local objective standards, requires parcel-specific review.

What should be screened?

• Whether the parcel is in an eligible single-family residential zone and urbanized area.
• Coastal zone, historic resources/districts, farmland, hazards, protected habitat and other statutory exclusions.
• Tenant history, rent-control or Ellis Act issues and demolition restrictions.
• Minimum resulting lot sizes, approximate 60/40 proportionality limits and legal access.
• Utilities, sewer, fire access, easements, parking and separate addresses.
• Owner-occupancy affidavit requirements for an urban lot split and restrictions on repeated subdivision.

Practical process

1. Title, survey and zoning/overlay review.
2. Architect or land-use professional prepares an eligibility and yield study.
3. Civil survey/subdivision work defines legal parcels, access and utilities.
4. Concept plans test parking, privacy, grading, drainage and constructability.
5. City application, agency corrections and recordation steps.
6. Building plans, structural/energy engineering, permits and construction.

What does it cost?

The subdivision itself is only part of the budget. Include survey, title/legal work, architecture, civil and utility engineering, geotechnical work, agency fees, demolition, service upgrades, driveways/fire access, financing, construction and contingency. A “cheap lot split” can become expensive when utilities or access are difficult.