California ADU Law in 2025: What LA Homeowners Can Now Build

California's ADU laws have undergone dramatic changes over the past several years, and 2025 brings additional clarity for homeowners throughout Los Angeles County. Whether you own a single-family home in Pasadena or a multifamily property in Sherman Oaks, new state legislation has expanded what you can legally build on your lot — often without the restrictions that blocked projects just three years ago.

What You Can Build on a Single-Family Lot

Under current California law, most single-family residential lots in LA County can now accommodate: one Accessory Dwelling Unit (ADU) up to 850 sq ft (or 1,000 sq ft if it includes multiple bedrooms); one Junior ADU (JADU) up to 500 sq ft, typically carved from an existing structure; and one attached ADU within or connected to the primary residence. Minimum lot size requirements have been eliminated statewide. Your lot size no longer dictates eligibility — only setbacks and height limits remain as constraints. This opened thousands of previously restricted lots in Altadena and East Pasadena.

SB 1211 (2024): Multifamily ADUs Dramatically Expanded

Senate Bill 1211, signed by Governor Newsom in September 2024 and effective January 1, 2025, expanded ADU rights for multifamily properties. Multifamily parcels (duplexes, triplexes, apartment buildings) can now add ADUs equal to 25% of existing units, with a minimum of two new ADUs per property. Prior law allowed a minimum of just one. Detached ADUs on multifamily lots must be permitted if they meet standard setback and height requirements. This change directly benefits duplex and small apartment building owners in Sherman Oaks, Pasadena's multi-family zones, and throughout unincorporated Altadena. Source: California Legislative Information (SB 1211, chaptered 2024).

AB 976: Owner-Occupancy Permanently Eliminated

AB 976, effective January 1, 2025, permanently prohibits local agencies from imposing owner-occupancy requirements on ADU properties. Previously, some ordinances required the property owner to live on-site as a condition of ADU approval. That restriction is now gone statewide. You can own a rental property in Malibu or Altadena and build an ADU without maintaining primary residence there. Source: California Legislative Information (AB 976, chaptered 2023).

Streamlined Permitting: What to Expect

State law requires local agencies to act on ADU permit applications within 60 days and to grant approval ministerially — no discretionary review — when the ADU meets objective development standards. Impact fees are completely waived for ADUs under 750 sq ft. In practice, LA County (for unincorporated Altadena) and the City of Pasadena have both implemented ADU-specific permit tracks. Typical permit turnaround in 2025 runs four to eight weeks for straightforward ADU applications. Source: CA HCD ADU Handbook 2024 (hcd.ca.gov).

LA County and Pasadena-Specific Overlays

State law sets the floor, but local rules still apply within limits. LA County (Altadena): Requires fire-resistive construction (WUI zone requirements where applicable) and minimum 4-foot rear and side setbacks for detached ADUs. City of Pasadena: 12 Historic Preservation overlay districts require HPO review for exterior modifications, but ADUs in rear yards typically fall outside these restrictions. City of Malibu: Properties in the Coastal Zone require a Coastal Development Permit, adding a review layer managed by the California Coastal Commission. Sources: LA County DRP (planning.lacounty.gov), CalMatters ADU tracker.

How DG Custom Construction Helps

DG Custom Construction & Electric handles the complete ADU process in-house: feasibility review, permit preparation, foundation, framing, electrical, and final inspection. Our C-10 electrical license means panel upgrades and ADU sub-panels are done by the same crew — no subcontracting delays. We operate throughout Pasadena, Altadena, Sherman Oaks, Malibu, and greater Los Angeles. Call us at (818) 876-2026 for a free feasibility consultation.