Yes, San Marcos allows SB 9 splits under its code sections 20.470 and 19.44, and the city maps every parcel as permitted, constrained or prohibited for SB 9. Its written rules are among the strictest in North County.
Free, about 30 seconds, no signup to see your answer.
San Marcos publishes specific SB 9 development and subdivision requirements, including parcel access and development limits. Homeowners should compare the city's published rules with current California housing law before relying on a proposed layout.
Related: how our property checker works, the statewide SB 9 rules, SB 9 lot split costs, and the free lot checker.
Governing rules: San Marcos Municipal Code 20.470 and 19.44, on top of state law (Cal. Gov. Code §§65852.21, 66411.7).
These are on the city's books, but SB 9 and later state housing laws may limit them. Our checker flags them for a hand look instead of ruling a lot out.
Published fee categories are informational, not a project quote. Applicability and total expenses depend on the city, parcel, proposed construction and current agency requirements. Schedule: City fees (effective September 1, 2026).
| Tentative parcel map | $9,391 |
| Parcel map (minor subdivision) | $5,160 |
| Public facilities fee | $6.88 per sq ft |
The city has no urban lot split line item, so these are the closest fees on its schedule. School, water and sewer fees are charged by other agencies. These are published city fees or the closest fee categories on the city's schedule, not a quote for an SB 9 application. Real costs depend on the project, required reviews, utilities and current schedules; survey, engineering, school, utility and recording costs are extra. Who pays what is set out in the written agreement for the new lot. City fee schedule.
Yes. Once the split records, the new lot is a separate legal parcel you can sell on its own, and you keep your house on the other one. Sell it direct and there's no realtor commission: In a direct sale without a homeowner listing agent, no listing-agent commission is charged to the homeowner. Escrow, title, lender, tax, permitting, and other expenses may still apply. The written agreement specifies which party pays each cost. See how selling part of your backyard works.
Yes, San Marcos allows SB 9 splits under its code sections 20.470 and 19.44, and the city maps every parcel as permitted, constrained or prohibited for SB 9. Its written rules are among the strictest in North County.
Each lot has to be at least 1,200 square feet, and the smaller lot at least 40% of the original lot. Areas over 25% slope and creeks don't count toward lot area.
Ministerial, under SMMC 19.44, with a grading plan.
No. In a direct sale without a homeowner listing agent, no listing-agent commission is charged to the homeowner. Escrow, title, lender, tax, permitting, and other expenses may still apply. The written agreement specifies which party pays each cost.
Type your address. We check it against the county maps and San Marcos's rules in about 30 seconds.
| City SB 9 rules | San Marcos Municipal Code 20.470 and 19.44 |
|---|---|
| Published fee schedule | City fees (effective September 1, 2026). The city has no urban lot split line item, so these are the closest fees on its schedule. School, water and sewer fees are charged by other agencies. |
| State SB 9 statute | Gov. Code §65852.21 and §66411.7 |
| Rules last read from city sources | September to October 2026 |
| Fees checked against official schedules | October 19, 2026 |
Rules read from the city's published code and fee schedules; last reviewed October 2026. Check with the city before you rely on any single number.