Buyer Basics

Zoning Questions Every First-Time Buyer Should Ask

Five zoning and permit questions to answer before you buy your first San Diego home, what California changed recently, and how Rudy can help you get answers from the city.

Updated October 2026 · Rudy Flores · Coldwell Banker West

Zoning sounds like something for developers, but it decides what you can do with your first home: add a room, build a backyard unit, finish the garage. A few questions asked before you buy can save a lot of surprises. Here they are, with how Rudy can help you get answers.

First: which city is it?

San Diego County has 18 incorporated cities plus unincorporated areas, and each has its own zoning code and permit process. Two homes a few blocks apart can answer to different jurisdictions. Find out which one governs the home you are considering, and look at that jurisdiction’s planning and building pages.

Five questions to answer before you close

What is the zoning, and what is allowed? Ask the planning office, or check the city’s public zoning map.
Is there any work that was done without a permit? California’s Transfer Disclosure Statement asks sellers about additions, structural changes and other work done without necessary permits. Read the answers and ask the city for the permit history.
Could the lot hold a backyard unit? State law gives many single-family lots the right to an ADU. The ADU return estimator helps you weigh the numbers.
Are there overlays? Coastal zone, historic review, hillside, airport or fire zones can add steps.
Is there an association? Its rules can be stricter than the city’s.

What California changed recently

Backyard and garage units. The state tightened the ADU rules again for 2026: cities have 15 days to tell an applicant whether an ADU application is complete, with silence counting as complete (SB 543); junior ADUs can carry an owner-occupancy rule only if they share a bathroom with the house (AB 1154); and a city’s ADU ordinance is void unless it is filed with the state’s housing department on time and answered promptly (SB 9 of 2025).
Two homes on one lot. Under SB 9 (2021), many single-family lots can hold a duplex or be divided into two lots through a ministerial process, with limits. AB 1061 widens it in 2026 to projects inside historic districts, as long as the structures are not individually designated.
Permit clocks. Two 2025 laws add deadlines: AB 253 allows a private plan checker when a jurisdiction exceeds its 30-business-day review estimate after entitlement, and AB 1308 gives final inspections 10 business days from notice that work is complete.

These follow Holland & Knight’s summary and the state’s ADU Handbook; confirm current details with the city.

How Rudy can help

Permits are not a mystery to Rudy. He spent 12 years in real estate development for the national telecom carriers, where every cell site meant a conversation with a city or county, and he brings those habits to San Diego County homeowners and buyers: the story is on his About page.

Tell Rudy the address and the idea. A few sentences and a photo are enough.
He looks up the basics: the zoning, any overlays, and what the jurisdiction says publicly.
He prepares you for the conversation with the planning department, and can join a call or visit where it helps.
You decide with real information, before you sign an offer or spend on plans.

This is guidance from a real estate professional, not legal, engineering or architectural advice.

Common questions

Do I need a permit to finish a garage?

Usually yes, and converting a garage to an ADU has its own rules. Ask the city before you buy or build.

What if the seller did unpermitted work?

Ask what it would take to legalize it and factor that into your offer.

Who do I call?

The city’s planning department for zoning, and the building department for permits.

A note on what this is

This page is general information from a real estate professional. It is not legal, engineering, architectural or tax advice, and it does not guarantee that any permit will be issued. Zoning and permit rules differ from one parcel to the next and are updated regularly: check with the city or county and with licensed professionals before you act.

Keep exploring

The first-time buyer guide — The whole process, step by step.
Property tax for first-time buyers — Budget it before you bid.
ADU return estimator — Weigh cost against rent.
About Rudy — Twelve years in telecom real estate, then homes.

Talk to a lender. Rates, loan programs and approvals come from lenders, not from websites or real estate agents. Talk to your own mortgage broker, or use our preferred lender, Point Mortgage Corporation (NMLS #231073), at (619) 475-4095. You are always free to choose any lender you like, and you can verify any lender’s license at nmlsconsumeraccess.org.

Sources

General information for orientation, not legal, tax, financial or appraisal advice. Details change; confirm anything that matters with the official source, your lender and your agent.