What does the City’s ADU Standard Plan Program change for a builder?
Inside the City of Los Angeles, the Department of Building and Safety (LADBS) runs a Standard Plan Program covering accessory dwelling units, single-family homes, and smaller structures such as pools and patio covers. Private professionals such as a California-licensed architect draw the designs to suit a range of site conditions, and LADBS admits one to its catalog only after verifying compliance with the Building, Residential, Green Building, and Energy Codes. The Department says a Standard Plan greatly reduces the time required for plan check, because the design itself no longer needs a full review.
The plans stay privately owned. A homeowner who picks one must contract with its designer for access, pricing, and terms of use, and the City states that pre-approval is not an endorsement of the designer or of their ability to complete the work. Designs may or may not be customizable, adjustments can add cost and more review, and new designs join the catalog on a rolling basis.
For a contractor the shortcut is real but partial. Every pre-approved plan still gets a final LADBS review of how it is adapted to the specific lot, covering site conditions and clearances, and the Department warns that localized soil conditions can require site-specific foundation work, structural design, or detailed engineering. It urges owners to confirm feasibility with LADBS before signing with a professional, and offers an optional AI pre-plan check before submittal. A Los Angeles ADU homeowner who has chosen a catalog design has done part of the scoping, so the estimate starts from a drawing instead of a wish list.
LADBS Standard Plan ProgramCity of Los Angeles or unincorporated County: which desk reviews the job?
Los Angeles is two review systems wearing one name. Addresses inside the City go to LADBS and City Planning. Addresses in unincorporated Los Angeles County, and in the contract cities the County serves, go to County Public Works, Building and Safety Division, with Regional Planning signing off on zoning. A contractor working the San Fernando Valley and the unincorporated pockets near Altadena faces different counters, forms, and plan checkers on jobs a few miles apart.
The County’s ADU page lays out an eight-step path. A complete package of architectural plans, structural plans, and T-24 energy calculations is screened first, at a Building and Safety district office or online through EPIC-LA. Regional Planning-approved plans can go in up front, or the applicant signs a waiver, but that approval must be in hand by step six, when every sign-off on the agency referral sheet is submitted. Plans are reviewed, corrected, and rechecked until approved, and then issuance and inspections follow.
The County’s published limits are 1,200 square feet for an ADU and 500 for a junior ADU, each with a kitchen and separate entrance, plus a fire-rated wall if attached or six feet of separation if detached. It also promotes converting existing single-story garages through an expedited process of standardized sheets, pre-construction meetings, and a construction guide, under the Board of Supervisors’ emergency housing declaration. A new single-story detached ADU can follow the County’s wood-frame provisions or Type V sheet, while a two-story detached unit requires a design professional. Ask early whether the address is City or County, because that sets what you will price.
Los Angeles County Public Works, Building and Safety: ADU/JADUWhat does a like-for-like rebuild look like in Altadena, the Palisades, and Malibu?
The Eaton and Palisades fires of January 2025 left a rebuild market split by jurisdiction. Altadena and the Santa Monica Mountains communities are unincorporated and rebuild through the County. Pacific Palisades sits inside the City of Los Angeles and is routed to the City’s own recovery program, while Malibu, Pasadena, and Sierra Madre each run separate municipal processes. The County’s recovery site states this routing outright, so the first question on a fire-rebuild lead is jurisdiction.
The County defines a like-for-like rebuild as a structure of the same size, location, and purpose as the one that burned, and says they get quicker review than more complex work. Modifications are allowed: in the Palisades Fire area, up to a 10 percent increase in floor area, size, height, or footprint; in the Eaton Fire area, 10 percent or 200 square feet, whichever is greater. Like-for-like structures are exempt from current Zoning Code requirements but must meet current Building, Fire, and Health and Safety Codes. Beyond that a rebuild is a full zoning project, and in Altadena the Community Standards District applies with a 20-foot minimum front setback.
Applications route to County Planning, Building and Safety, Fire, and Public Health, and both debris-removal phases must be cleared before approval issues. On a fire-zone lead, ask whether the lot is cleared and whether the owner wants the old footprint or something larger, since that sets the review path. Separately, state law under SB 9 gives single-family lot owners a ministerial path to split a lot and add units, which surfaces in Los Angeles addition calls too.
LA County Recovers: Like-for-Like Rebuild