Can you build an ADU in Sun Valley?

Are Sun Valley homeowners actually getting ADU permits?

Yes, at a steady pace. LADBS issued 112 ADU and JADU building permits in 91352 in 2023, 129 in 2024 and 152 in 2025, plus 114 from January 1 through October 3, 2026 ³. At that rate 2026 will finish about level with 2025.

Of the 266 permits issued since January 2025, 106 were filed as alterations to an existing building, 90 as new buildings and 70 as additions ³. These are permits, not finished homes, and one project can carry more than one permit. For how 91352 ranks against the rest of the Valley, see ADU permits by Valley ZIP.

How big is a typical Sun Valley lot, and how is it zoned?

Bigger than most of the flat Valley. We counted 6,718 City of LA single-family parcels in 91352 on the County Assessor's parcel map. Half of them fall between 6,383 and 9,072 sq ft, 1,368 are 10,000 sq ft or more, and 469 are 20,000 sq ft or more ¹.

Most of those lots are zoned R1 (4,360 parcels), with 951 in RS and 866 in RA, the larger-lot zone where many horse properties sit ². Look up your own parcel on ZIMAS, which shows its zoning and its permit history ⁵. Zoning matters less than you might expect for the state-law option: one detached ADU of up to 800 sq ft with 4-foot side and rear setbacks is allowed on a lot with a single-family house ⁴.

My street backs up to industrial zoning. Can I still build an ADU?

Usually yes, but read the zone printed on your own lot first. ADU rights follow zones where a home is a permitted use, and City Planning says a zone that only allows a caretaker or watchman unit as part of an industrial development does not count ⁶. By our count about 90 single-family parcels in 91352 sit inside an M1, M2 or MR1 zone ². If yours is one of them, ask a planner before you pay for drawings.

For the much larger group of homes next to industry, the overlay to know is CUGU (Clean Up Green Up). Its purpose is to reduce the health impacts of concentrated industry, traffic and freight corridors near homes and schools ⁷, and 2,484 single-family parcels in 91352, about 37 percent, carry the CUGU suffix ². When a new stand-alone building with a dwelling sits next to, across the street from, or corner to corner with a listed industrial use, the code adds landscaping for the yards that abut that use ⁸, and LADBS does not issue the permit until a CUGU review is done ⁹. Ask the planner how that review applies to an ADU on your lot.

Freeways matter too. LADBS says buildings within 1,000 feet of a freeway need air filters rated MERV 13 or better ¹⁰. About 1,862 single-family parcels in 91352, or 28 percent, have their center within 1,000 feet of the I-5, the 170 or the 210 on the city's freeway map ¹¹. That is a rough screen, so measure from your own lot.

I keep horses, or my neighbor does. Does that affect where an ADU can go?

It can. 781 single-family parcels in 91352 are in a K (equinekeeping) district ². LADBS guidance says new habitable rooms must be at least 35 feet from a legally established horse use on a neighbor's lot, and in a K district a horse enclosure must be at least 35 feet from habitable rooms on its own lot ¹².

State ADU law complicates this. In June 2026, City Planning told the City Council that state exemptions from local setback and distancing rules can leave existing, legal corrals nonconforming, and it proposed code changes ¹³. As of October 2026, ask LADBS how the 35-foot rule applies before you fix the ADU's location.

In the Stonehurst HPOZ, a 92-home historic district of river-rock houses, many on horse or animal-keeping lots ¹⁴, design review still applies. But an HPOZ standard cannot shrink a State ADU below 800 sq ft ¹⁵.

Is my Sun Valley lot in a fire zone or a hillside area?

About one in five is. On the city's Very High Fire Hazard Severity Zone layer, last edited in 2019, 1,431 single-family parcels in 91352 have their center in the zone, and 1,106 of those are also in a Hillside Area ¹⁶. These are mostly the foothill streets toward La Tuna Canyon and Shadow Hills, not the flat blocks near San Fernando Road.

On a lot that is in both, the city code prohibits ADUs except in a few cases, but City Planning says that restriction cannot be enforced on State ADUs ¹⁷. In practice the 800 sq ft state option stays open while the bigger city-ordinance ADU may not. The details are in ADUs and the Hillside Ordinance.

What about sewer, water and power on a Sun Valley lot?

Most lots are close to a public sewer, but not all. On the city's sewer map, 496 single-family parcels in 91352, about 7 percent, have their center more than 200 feet from any public sewer pipe ¹⁸. That is a screen, not a ruling: the Bureau of Engineering measures from the property, and when a property is more than 200 feet from a sewer main the owner may choose septic ¹⁹. The options are in Sewer main over 200 feet away.

For water, an ADU created inside existing space cannot be required to get a new or separate connection, but a new detached unit can be ²⁰. If you choose your own LADWP water service, the 2026-27 charge for a 1-inch domestic service and meter is $7,407 to $7,466 ²¹. More on that in LADWP water meters for ADUs. Have an electrician look at your panel before design; see the 200-amp question.

What should I check first, and in what order?

Start with what is printed on the city's records, then move to the ground.

1. Zone and overlays on ZIMAS: look for M, CUGU, K, HPOZ, fire zone and Hillside ⁵.
2. Neighbors: whether an industrial use or a horse corral sits next door or across the street ⁸¹².
3. Freeway distance: whether you are within 1,000 feet, which sets the filter rating ¹⁰.
4. Sewer: how far your lot is from the main ¹⁹.
5. Water and power: whether you want a separate meter, and what your panel can carry ²⁰²¹.

This is the kind of thing a lot check settles in one pass, before you pay for plans.

Quick answers

Sources

1. LA County Assessor parcel layer (LACounty_Parcel), single-family parcels in ZIP 91352, City of Los Angeles, LA County Assessor (Greenlight analysis). Facts checked 2026-10-11
2. LA City GeoHub Generalized Zoning layer, joined to the 91352 single-family parcels in s1, City of Los Angeles GeoHub (Greenlight analysis). Facts checked 2026-10-11
3. Building Permits Issued from 2020 to Present (N), dataset pi9x-tg5x, ZIP 91352, LADBS via City of Los Angeles Open Data (Greenlight query). Facts checked 2026-10-11
4. Accessory Dwelling Unit Handbook (March 2026), 66323 Units: Single-Family Detached ADUs, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
5. Zoning Search (ZIMAS), Los Angeles City Planning. Facts checked 2026-10-11
6. ZA Memo No. 143 Revision 1, Q.2: zones that allow residential use, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
7. LAMC Sec. 13.18, CUGU Clean Up Green Up District: Purpose (text as of 2026-10-05), City of Los Angeles Municipal Code, via GoCodebook. Facts checked 2026-10-11
8. LAMC Sec. 13.18 D-F: definitions, qualifying criteria, publicly habitable spaces adjacent to subject uses, City of Los Angeles Municipal Code, via GoCodebook. Facts checked 2026-10-11
9. LAMC Sec. 13.18 G: Issuance of building permits, City of Los Angeles Municipal Code, via GoCodebook. Facts checked 2026-10-11
10. FAQ: I am installing a new air conditioning system, what type of filters do I need to use?, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-11
11. LA City GeoHub Freeways (BOE) layer, measured against the 91352 single-family parcels in s1, City of Los Angeles GeoHub (Greenlight analysis). Facts checked 2026-10-11
12. Information Bulletin P/ZC 2023-018: Equinekeeping, Los Angeles Department of Building and Safety (LADBS). Facts checked 2026-10-11
13. Report back on recommendations relative to equestrian uses, CF 16-1468-S4 and CF 25-0096 (June 24, 2026), Los Angeles Department of City Planning. Facts checked 2026-10-11
14. Stonehurst Historic Preservation Overlay Zone, Los Angeles City Planning. Facts checked 2026-10-11
15. ZA Memo No. 143 Revision 1: State ADUs and local standards, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
16. LA City GeoHub Very High Fire Hazard Severity Zones and Hillside Ordinance layers, joined to the 91352 single-family parcels in s1, City of Los Angeles GeoHub (Greenlight analysis). Facts checked 2026-10-11
17. ZA Memo No. 143 Revision 1, Q.42: VHFHSZ and Hillside Areas, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
18. LA City GeoHub Sewer Pipes layer, measured against the 91352 single-family parcels in s1, City of Los Angeles Bureau of Engineering via GeoHub (Greenlight analysis). Facts checked 2026-10-11
19. Sewer (S) Permits: S-Permit Processing Procedures, City of Los Angeles Bureau of Engineering (BOE) Permit Manual. Facts checked 2026-10-11
20. Accessory Dwelling Unit Handbook (March 2026), Utilities: new or separate connections, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
21. Schedule of Charges for Water Facilities, Fiscal Year 2026/2027 (rev. 6/26), Los Angeles Department of Water and Power (LADWP). Facts checked 2026-10-11
22. Accessory Dwelling Unit Handbook (March 2026), Lot size, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
23. Accessory Dwelling Unit Handbook (March 2026), Summary of Recent Changes, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11

Greenlight is not a contractor, architect or engineer, and this is not legal advice. Rules change; every fact here shows the date we last checked it.