Can you build an ADU in North Hills?

How big is a typical North Hills lot?

Bigger than in most of the flat Valley. We counted 8,149 City of Los Angeles single-family parcels in 91343 on the LA County Assessor's parcel map. The median lot is 7,850 sq ft, and half of all lots fall between 7,504 and 8,661 sq ft ¹. An 800 sq ft backyard house takes up about 10 percent of a median lot.

The same count put the median lot at 6,968 sq ft in Pacoima and 6,639 sq ft in Reseda ¹, so a typical North Hills owner starts with roughly 900 to 1,200 more square feet of land. For a Pacoima comparison, see our Pacoima lot guide.

The count also found no single-family parcel in 91343 touching the city's Very High Fire Hazard Severity Zone map ¹. That map layer was last edited in 2019, so confirm your own parcel on ZIMAS, the City Planning map that shows a parcel's zoning and permit history ¹¹.

My lot is zoned RS or RA, not R1. Can I still build an ADU?

Yes. City Planning says ADUs are permitted through a ministerial process in all areas zoned for single-family or multifamily homes where there is a home on the lot ⁶, and RS and RA both allow one-family homes ³⁴.

It matters in North Hills because R1 is rare here. Of the 427 ADU and JADU permits LADBS issued in 91343 from January 2023 through October 3, 2026, 286 were on lots zoned RS-1 and 115 on lots zoned RA-1. Only 14 were on some form of R1 ².

Here is what the two zones set for the main house, according to City Planning's zoning summary:

• RS (Suburban): a 7,500 sq ft minimum lot area, a 60-foot minimum lot width, a 20-foot minimum rear yard and side yards of 5 feet ³.
• RA (Suburban, with limited agricultural uses): a 17,500 sq ft minimum lot area, a 70-foot minimum lot width and side yards of 10 feet ⁴.

Those numbers govern the house and new lots, not your ADU. A State ADU of up to 800 sq ft needs only 4-foot side and rear setbacks ⁵, even where the RA zone asks 10 feet of the house. And a lot zoned RA that is smaller than 17,500 sq ft is not disqualified, because state law bars cities from setting a minimum lot size for ADUs ¹³. Our setback guide covers the details.

How big can my backyard house be in North Hills?

At least 800 sq ft, and up to 1,200 sq ft if your lot has room under the city's rules. Los Angeles gives you two tracks.

• State ADU. One detached unit of up to 800 sq ft with 4-foot side and rear setbacks, and a height limit of 16, 18 or 20 feet depending on conditions ⁵. The city's residential floor area limit, called RFA, applies in the RS and RA zones but cannot be enforced against a State ADU ⁷.
• Ordinance ADU. Under the city's own ordinance a detached unit can reach 1,200 sq ft and two stories ⁸, but RFA, front yard setbacks or lot coverage may limit it further ⁷.

On a North Hills lot, the size of the existing house is usually what decides whether a unit bigger than 800 sq ft fits under RFA. If the house is already large, the State ADU is the safer starting point. Heights are explained in our ADU height guide.

Are North Hills owners building new, or converting what they have?

Mostly working with existing buildings. Of the 204 ADU and JADU permits issued in 91343 since January 1, 2025, 115 were filed as alterations to an existing building, 51 as new buildings and 38 as additions ².

State law allows detached garages and other existing accessory structures to be converted to ADUs ¹⁵, and the city cannot require you to replace the parking you lose when a garage is converted or torn down for an ADU ¹⁶. The usual catch is the garage's own history: if it was never permitted, the conversion can turn into a rebuild. Our guide on how to check if your garage was permitted walks through that lookup, and JADU vs ADU covers a unit inside the house.

Could I put more than one unit on a North Hills lot?

Often, yes. City Planning allows a detached State ADU to be combined with an attached Ordinance ADU, or an attached State ADU with a detached Ordinance ADU ⁹. A JADU can generally be added to those options as well ⁹.

City Planning also says a duplex under SB 9 can be built in a single-family zone that has not been split under an SB 9 urban lot split, together with up to two State detached ADUs ¹⁰. Whether that path applies to your RS or RA lot, and whether the lot has room for it, is a question for a City Planning counter before you design anything.

Are North Hills homeowners actually getting ADU permits?

Yes, though 2026 is running slower. LADBS issued 46 ADU and JADU building permits in 91343 in 2020, 93 in 2023, 130 in 2024 and 133 in 2025, plus 71 from January 1 through October 3, 2026 ². At that pace, 2026 would finish near 94 permits, about 30 percent below 2025.

These counts are permits, not homes. One project can carry more than one permit, so read them as a trend, and a permit issued is not a unit finished. For how North Hills compares with other Valley ZIPs, see ADU permits in the San Fernando Valley by ZIP.

What should I check first on a North Hills lot?

Work from the cheapest answer to the most expensive one.

1. ZIMAS: your exact zone (RS, RA or something else), any Q or T conditions on it, and the permit history of the house and garage ¹¹. North Hills is one of three neighborhoods in the Mission Hills - Panorama City - North Hills Community Plan, which City Planning says was last updated in 1995 ¹².
2. House size: if you want more than 800 sq ft, find out how much RFA the existing house already uses ⁷.
3. Garage history: whether the garage you want to convert was permitted (garage check).
4. Utilities: the sewer (sewer main guide), the water meter (LADWP meter guide) and your electrical panel (panel guide).

Once your application is complete, the city must approve or deny it within 60 days ¹⁴; our plan check timeline guide covers what happens before that clock starts. 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 91343, City of Los Angeles; with LA City GeoHub Very High Fire Hazard Severity Zones layer, LA County Assessor / City of Los Angeles GeoHub (Greenlight analysis). Facts checked 2026-10-11
2. Building Permits Issued from 2020 to Present (N), dataset pi9x-tg5x, ZIP 91343, LADBS via City of Los Angeles Open Data (Greenlight query). Facts checked 2026-10-11
3. Generalized Summary of Zoning Regulations (updated January 2026), RS Suburban row, Los Angeles City Planning. Facts checked 2026-10-11
4. Generalized Summary of Zoning Regulations (updated January 2026), RA Suburban row, Los Angeles City Planning. Facts checked 2026-10-11
5. 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
6. ZA Memo No. 143 Revision 1, Accessory Dwelling Units (August 2025), Summary of ADU and JADU Development Standards, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
7. ZA Memo No. 143 Revision 1, Accessory Dwelling Units (August 2025), ADU size and RFA, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
8. ZA Memo No. 143 Revision 1, ADU types summary table (Ordinance ADU vs State ADU), Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
9. ZA Memo No. 143 Revision 1, Combinations of ADUs and JADUs, Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
10. ZA Memo No. 143 Revision 1, ADUs with SB 9 (2021), Los Angeles City Planning, Office of Zoning Administration. Facts checked 2026-10-11
11. Zoning Search (ZIMAS), Los Angeles City Planning. Facts checked 2026-10-11
12. Mission Hills - Panorama City - North Hills Community Plan, Los Angeles City Planning. Facts checked 2026-10-11
13. Accessory Dwelling Unit Handbook (March 2026), Lot size, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
14. Accessory Dwelling Unit Handbook (March 2026), Summary of Recent Changes, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
15. Accessory Dwelling Unit Handbook (March 2026), Detached ADUs, California Department of Housing and Community Development (HCD). Facts checked 2026-10-11
16. Accessory Dwelling Unit Handbook (March 2026), Parking, 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.