A field guide for the rest of us
Real numbers, real timelines, real local rules — written for homeowners who want the data before the sales pitch. Permitting math, not contractor copy.
Four figures we keep coming back to. They explain why this is the biggest housing story in California — and why the friction is paperwork, not zoning.
ADU permits issued in California in 2024 — up from ~1,200 ten years ago.
HCD · Annual Progress ReportTurnkey 800 sqft detached ADU at standard finishes, LA-area, 2026 pricing.
Source · This dossier, calibrated 2026-05Realistic end-to-end permitting window across LA-area cities, application to issuance.
Source · City planning portals, 2026-05The statewide threshold below which most school & park impact fees are waived.
HCD · ADU HandbookEvery California city has its own rulebook. Open a dossier to see the permit fee, timeline, notable local rules, and rent ranges — drawn directly from each city's planning portal.
Los Angeles County
Los Angeles County
Los Angeles County
Los Angeles County
Los Angeles County
Pick a city, an ADU type, a size, and a finish tier. We pull the build cost band from our research, add the city's actual permit fees, and show you a defensible range — not a contractor's optimistic quote.
Using our LA permit-fee data and 2026 build-cost bands, here's what a typical mid-size ADU pencils out to. Your number will vary with lot conditions and finish choices — that's why the full estimator lets you adjust every input.
From "we're thinking about it" to a certificate of occupancy. Most LA-area projects run 10 to 14 months end-to-end — slower in Pasadena and Santa Monica, faster with a pre-approved standard plan.
Walk the lot. Confirm zoning, setbacks, easements, hillside or coastal overlays. Pick a rough size and ADU type. Often paired with a free architect consult.
Architect produces permit-ready plans — site plan, floor plans, elevations, structural notes, MEP schematics. Soils report and survey ordered if the lot requires them.
Submit to the city. State law caps the first review at 60 days, but most projects go through two or three rounds of corrections — that's where the real timeline lives.
Pay fees. Pull the permit. Line up the contractor's crew, financing draw schedule, and utility-coordination paperwork.
Site prep, foundation, framing, MEP rough-in, drywall, finishes. Inspections happen at each gate. Detached ADUs typically run 5–8 months; garage conversions run 3–5 months.
Final building, electrical, plumbing, and (if applicable) fire inspections. Address punch-list items. Once the C of O is issued, you can legally rent it.
End-to-end — typically 10 to 14 months
Five statutes you should know about before signing anything. Each one moved a meaningful piece of the rulebook — and at least two of them quietly changed the financial calculus for owners.
Owners of multifamily parcels (duplex and up) can now build up to eight detached ADUs by-right, capped at the number of existing primary units. The bill also raised the statewide minimum ADU height from 16 to 18 feet for parcels near transit, giving room for a usable second story.
Owners of duplex, triplex, and larger multifamily parcels.Cities may now adopt an ordinance allowing ADUs to be sold as condominiums separately from the primary residence. Adoption is permissive — only a handful of California cities have opted in so far, but it's a meaningful exit-path option to track.
Single-family homeowners in cities that have opted in.Cities cannot require the owner to live on-site as a condition of permitting a new ADU. This makes the ADU a much more flexible long-term financial asset — you can move, keep the property, and rent both units.
Anyone building an ADU and weighing whether to keep the home long-term.Reduces barriers to permitting unpermitted ADUs built before January 2020. Cities can no longer require correction to current code for items that were code-compliant at the original build date, with limited health-and-safety exceptions.
Owners with informal ADUs, conversions, or backyard cottages.Detached ADUs up to 800 sqft, 16 feet tall, with 4-foot setbacks are approved ministerially — no discretionary review, no design review, no public hearing. Cities must act within 60 days of a complete application.
Anyone building a code-minimum detached ADU.We're talking about money. That's fine. Here's what an ADU actually does to your balance sheet — based on Fannie Mae appraisal data and California rent surveys, not contractor pitches.
Note 01 · Value
That's well above the build cost in most LA-area neighborhoods — the asset side of the trade is favorable before you count a dollar of rent.
+25–35%Note 02 · Income
$1,800–$3,500/month across LA-area cities, against $1,400–$2,200/month in mortgage-payment-equivalent at typical financed build costs.
$2.4k / mo · medianNote 03 · Flexibility
AB 976 made owner-occupancy mandates permanently illegal. AB 1033 lets cities allow ADUs to be sold separately as condominiums. The exit-ramps are wider than they used to be.
Two doors. One title (for now).Drawn from the conversations homeowners actually have with their architects and permit consultants. We keep this list short and editorial — not a content farm.
We hand-pick the contractors in your city who actually permit and finish ADUs — not the ones with the loudest ads. No spam. No obligation. You read the bids and decide.
Permit fees, timelines, and notable rules are sourced from each city's planning portal as of May 2026. Statewide statutes are quoted from the California Legislature's public bill record. Cost benchmarks are calibrated against HCD-published data and recent contractor surveys.