SB9 LOT SPLITS & DUPLEXES, SAN DIEGO COUNTY

SB9: Lot Splits & Backyard Homes

California’s SB9 lets many single-family lots add a second unit, split into two parcels, or both, with up to four homes on what was one property. Whether your lot qualifies, and whether the numbers work, depends entirely on the parcel: zoning, overlays, existing easements, utility routing, and how the jurisdiction applies the state law. That’s where I start.

Does your lot qualify?

SB9 excludes some properties: historic districts, high fire severity zones without mitigation, environmentally constrained sites, and lots where a split would displace protected tenants. San Diego jurisdictions each apply the rules differently. Before you sketch anything, I run the parcel: base zone, overlays, minimum lot sizes after split, setbacks, and access requirements. You get a clear yes, no, or here’s-what-it-takes.

Lot split, second unit, or both?

An urban lot split creates two sellable parcels and real value creation, but with owner-occupancy commitments and mapping costs. A second unit without a split is simpler and keeps everything on one title. Which path pencils depends on your goals: rental income, housing family, or building equity to sell. I’ll walk you through the tradeoffs with real numbers before you commit to either.

What I handle

Feasibility, design, permit drawings, plan check, and corrections, plus coordinating the surveyor, civil engineer, structural engineer, and Title 24 consultant. SB9 projects live or die on parcel research and jurisdiction handling. Twenty years of San Diego plan check experience means fewer surprises after you’ve committed.