Z-NET Jurisdiction & Zoning Lookup (LA County)

Z-NET: The First Thing Every LA ADU Owner Should Do Before Spending a Dime If you're thinking about building an accessory dwelling unit ADU, junior ADU, or...

Written by 1-800-ADU-Pros

Last updated: July 16, 2026•6 min read

Z-NET Jurisdiction & Zoning Lookup (LA County)

Z-NET: The First Thing Every LA ADU Owner Should Do (Before Spending a Dime)

If you're thinking about building an accessory dwelling unit (ADU), junior ADU, or tiny home anywhere in the Los Angeles area, there's one free, five-minute step that comes before architects, before contractors, and before any permit application: confirming who actually governs your property. The tool for that is Z-NET, run by the LA County Department of Regional Planning (DRP).

Get this step wrong and everything downstream goes sideways — you'll chase the wrong rules, the wrong portal, and the wrong fee schedule. Get it right and the rest of the process finally makes sense.

What Z-NET Actually Is

Z-NET (short for the "Find Your Zoning" mapping app) is a free, public, interactive GIS map. You type in your address or Assessor Parcel Number (APN), and it shows your property's zoning, general-plan land-use category, and any overlay districts.

It is not a permit and not an application. Nothing gets filed, nothing gets approved, and there's no fee. It's purely a lookup — but it's the lookup that determines every department, portal, and form you'll deal with afterward.

Why Jurisdiction Is the Whole Ballgame

Los Angeles County has 88 incorporated cities plus a huge amount of unincorporated land — more than 65% of the county's area, home to over a million people. Your parcel falls into exactly one of three buckets:

Unincorporated LA County — DRP is your planning department.
City of Los Angeles — a completely separate department and portal.
One of the other 87 cities (Pasadena, Long Beach, Santa Monica, etc.) — each with its own rules.

Here's the catch that trips up almost everyone: your mailing address lies. Plenty of homes that read "Los Angeles, CA" are actually unincorporated County — Altadena, East LA, Florence-Firestone, and Hacienda Heights are classic examples. The post office doesn't care about jurisdiction; the permit office does.

Each of these jurisdictions interprets California's state ADU law a little differently — on setbacks, height, size, and parking. Building to the wrong jurisdiction's code is a fast way to waste money on plans you can't use.

How to Use Z-NET (Step by Step)

Open Z-NET (linked from DRP's "Find My Zoning" page) and accept the disclaimer.
Type in your address or APN, or click your parcel on the map.
Read the result.

If you see zoning data

A zoning code and land-use info means your property is in unincorporated LA County, and DRP is your planning department. Write down the zoning code and any overlays.

If your parcel is "masked out in white"

A blank white parcel isn't a glitch — it's the answer. White means your property sits inside a city, so the County has no jurisdiction. Now you switch tools:

City of LA? Use the City's own zoning tool, ZIMAS (zimas.lacity.org), or the City Planning zoning search.
Any other city? Look up that city's planning department and ADU rules directly.

Don't Confuse Z-NET with ZIMAS

This is the single most common mix-up. Z-NET covers unincorporated County only. ZIMAS covers the City of LA only. They are different tools for different jurisdictions. Using the wrong one returns no useful zoning data and sends you down a dead end. (One more edge case: Z-NET's zoning layer excludes Santa Catalina and San Clemente islands.)

What to Capture Before You Move On

Once you've confirmed your jurisdiction, note three things:

Your zoning designation (e.g., the residential zone code).
Any overlay districts — hillside, flood, fire-hazard, etc. These can quietly change what you're allowed to build, so flag them now rather than at plan check.
The right department and portal for your jurisdiction.

If you'd like a human to interpret the result, DRP offers free virtual planner counseling — handy if your overlays look complicated.

The Bottom Line

Z-NET costs nothing, takes minutes, and answers the one question that shapes your entire ADU project: who's in charge of your parcel? Do it first. Everything else — the forms, the fees, the plan check — only makes sense once you know whether you're talking to LA County, the City of LA, or a city of your own.

Sources: LA County Planning — ADU page, Find My Zoning, Z-NET, Unincorporated LA County; LA City Planning — Zoning Search.

Reference card

Official number: N/A — Z-NET is a free GIS lookup tool, not a numbered permit or form
Issuing body: Los Angeles County Department of Regional Planning (DRP)
What it is: Z-NET ("Find your zoning") is the LA County Department of Regional Planning's free, public, interactive GIS web-mapping application. You type in an address or parcel number (APN) and it returns the property's zoning designation, general plan land-use category, and any overlay districts — but its most important job for an ADU project is confirming jurisdiction. It is NOT a permit or an application; nothing is filed and nothing is approved. It is purely an informational lookup that tells you which government body controls your parcel before you spend money on plans. Z-NET only contains data for the unincorporated areas of LA County (everything outside the 88 incorporated cities, except Santa Catalina and San Clemente islands). If your parcel sits inside a city, it appears "masked out in white" — and that masking is itself the answer: the County is not your planning authority, so you must go to that city instead.
Who needs it: Anyone considering an ADU, JADU, or tiny home anywhere in the greater LA area should run this lookup first — it is the mandatory orientation step. You specifically need it when you are unsure whether your property is in unincorporated LA County, the City of Los Angeles, or one of the other 87 incorporated cities. You can skip Z-NET only if you already know with certainty which jurisdiction governs your parcel (e.g., you've pulled a recent County permit, or confirmed it via your property tax bill or the Assessor's parcel viewer). If Z-NET shows your property masked in white, you are inside a city and Z-NET cannot give you zoning — you'll use the City of LA's ZIMAS tool or your city's planning department instead.
Fees: Free. Z-NET is a public lookup tool with no fee, no account, and no application charge. (Downstream ADU permit and plan-check fees are charged later by whichever jurisdiction Z-NET points you to — they are not part of this step.)
Timeline: Instant. Results return in seconds. Confirming your jurisdiction and zoning typically takes only a few minutes. If you want a planner to interpret the result, DRP offers free virtual counseling ("Connect with a planner"), which may take a day or two to schedule.

Requirements

Your property street address OR Assessor Parcel Number (APN) — either works as a search input
Internet access and a web browser (desktop recommended; the map is easier to read on a larger screen)
Nothing else: no account, no login, no documents, and no payment are required

How to file

Open Z-NET at https://experience.arcgis.com/experience/0eecc2d2d0b944a787f282420c8b290c/ (linked from the DRP 'Find My Zoning' page) and accept the disclaimer terms
Enter your property address (or APN) in the search box, or click your parcel directly on the map
Read the result: if a zoning designation and land-use info appear, your property is in unincorporated LA County and DRP is your planning department
If your parcel area is shown blanked out / masked in white, your property is inside one of LA County's 88 incorporated cities — the County has no jurisdiction
If you're in the City of Los Angeles, switch to the City's zoning tool, ZIMAS (zimas.lacity.org), or the City Planning zoning search at https://planning.lacity.gov/zoning/zoning-search
If you're in any other city (e.g., Pasadena, Long Beach, Santa Monica), look up that city's own planning/zoning portal and ADU rules
Record your zoning code and overlays — you'll reuse them on every form, portal, and plan-check submittal that follows

Common pitfalls

Assuming an 'LA' mailing address means City of LA — many addresses that read 'Los Angeles, CA' are actually unincorporated County (think Altadena, East LA, Florence-Firestone, Hacienda Heights). Z-NET settles it.
Treating the white-masked area as a Z-NET error. White = your parcel is inside a city, which means you're in the wrong tool — go to that city's portal.
Confusing Z-NET with ZIMAS. Z-NET is unincorporated COUNTY only; ZIMAS is City of LA only. Using the wrong one for your parcel gives you no usable zoning data.
Skipping Z-NET and ordering ADU plans for the wrong department's rules — County, City of LA, and the other 87 cities each interpret state ADU law differently, so building to the wrong code wastes time and money.
Relying on Z-NET inside an incorporated city for setbacks/size limits. Even when a city falls geographically inside the County, Z-NET will not show its zoning — only the city can.
Forgetting the islands. Z-NET's zoning layer excludes Santa Catalina and San Clemente islands, so it won't help there.
Reading zoning but ignoring overlays. Hillside, flood, fire-hazard, or other overlay districts shown in Z-NET can change what's allowed — note them now, not at plan check.

Sources

Explore more:Permits & Feasibility

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