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Call (916) 436-3776SB 9 Lot Splits & Duplexes California
How Does an SB 9 Lot Split or Duplex Work in California in 2026?
California's SB 9 lets you add units to a qualifying single-family lot by right: you can build a second unit (a duplex or a house plus an ADU), split the lot into two parcels, or both, up to four units on a former single-family lot. Approval is ministerial when objective criteria are met. Eligibility depends on single-family zoning, an urban location, a 40/60 lot-size split, tenant-protection rules, and each city's standards, so feasibility must be confirmed locally first. Serve First checks feasibility and handles the real estate; Ashlar Lending finances the build; Ashlar LDA prepares the documents.
California's SB 9, the HOME Act, lets many single-family lots do more. On a qualifying parcel you can build a second unit (a duplex, or a house plus an ADU), split one lot into two, or both, potentially turning a single home into as many as four units. Approval is ministerial (by-right), meaning no discretionary hearing when the objective criteria are met. It's a genuine opportunity to add units, income, and value, but eligibility hinges on zoning, location, lot geometry, tenant-protection rules, and each city's own standards, so a real feasibility check comes first. This guide covers how SB 9 works and how to pursue it, then links to a guide for your area. Serve First checks feasibility and handles the real estate; Ashlar Lending finances the build; Ashlar LDA prepares the documents.
One family. Land, financing, and paperwork.
Turn one lot into more, with the whole project supported
An SB 9 project can add units and value to a single-family lot, but it takes feasibility, financing, and documentation. The Ashlar Brands family helps across all three:
- Serve First Realty helps you find an SB 9-eligible lot to buy, assess whether your current property qualifies, and sell the newly created lot or the finished units to the right buyers.
- Ashlar Lending Inc. (NMLS #2699657) can arrange construction or renovation financing to build the new duplex or second home, and model the numbers: build cost against rent or resale, so the project pencils.
- Ashlar LDA, Inc., a bonded and registered Legal Document Assistant, can prepare deeds, the owner-occupancy affidavit an urban lot split requires, and related documents at your direction.
These are separate businesses in the Ashlar Brands family. Serve First is a real estate brokerage, not a lender, contractor, or law firm. SB 9 eligibility and local standards vary by jurisdiction and must be confirmed with your city or county. A Legal Document Assistant prepares documents at your direction and is not a substitute for an attorney.