Can you build an ADU in Mount Washington, Los Angeles?

Yes — about 99% of Mount Washington's roughly 6,453 analyzed single-family lots can add an ADU by-right. Most are zoned R1, which typically allows a detached ADU up to about 1,200 sq ft. These are zoning-only estimates; overlays like hillside, coastal, or historic can change the answer, so check your exact address for the rule that applies to your lot.

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ADU eligibility in Mount Washington

Lots analyzed
6,453
Likely eligible
99%
Typical max size
1,200 sq ft
Median lot
5,274 sq ft

Typical zoning in Mount Washington

The most common zones here, by number of analyzed lots. Your parcel’s zone sets which ADU rules apply.

ZoneLotsADU outlook
R15,270Allowed
RE20555Allowed
RE11174Allowed
RE40122Allowed
RD289Allowed

Eligibility is zoning-only (zoning-only (overlays excluded; see checker for per-lot verdict)). Ruleset la-2026.06. Neighborhood boundaries: Los Angeles Times / Mapping L.A. (CC BY 4.0).

Mount Washington ADU questions

In most of Mount Washington, yes. About 99% of its analyzed single-family lots can add an accessory dwelling unit by-right, most commonly on R1-zoned parcels. Your lot's exact answer depends on its zone, size, and any overlays — enter your address to see the rule that applies to you.

ADUs in other LA neighborhoods

North HillsNorth HollywoodNorthridgePacific PalisadesPacoimaPalmsPanorama CityPico-Robertson

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