ADU Guides
Straight answers to the questions SoCal homeowners ask most before building an ADU.
AB 1033: Can You Sell an ADU Separately in California?How AB 1033 lets California cities allow ADUs to be sold as condominiums, which jurisdictions have opted in, the requirements involved, and what it means for Southern California homeowners.
How Much Does It Cost to Build an ADU in Southern California?Realistic planning ranges for detached, attached, garage conversion, JADU, prefab and two-story ADUs in Los Angeles, Orange, San Diego, Riverside, San Bernardino and Ventura counties.
The ADU Permit Process in California: Step by Step (2026)How ADU permitting works in Southern California in 2026, including the 15-business-day completeness check, the 60-day approval clock, plan check, fees and inspections, with sources.
ADU Rental Income and Property Taxes in California: What to ExpectHow ADU rent, Prop 13 reassessment, income taxes and rental rules work for Southern California owners, with honest caveats and official sources.
Garage Conversion ADU Cost in Southern California (and What Drives It)What it costs to convert a garage into an ADU in Los Angeles, Orange, San Diego and the Inland Empire, plus the parking, setback and code rules that apply.How Long Does It Take to Build an ADU in Southern California?A realistic ADU timeline for Southern California, covering feasibility, design, permits, construction and final, by ADU type, with tips to avoid the most common delays.
How to Choose an ADU Builder in Southern California: 15-Point ChecklistHow to vet ADU builders in Los Angeles, Orange, San Diego, Riverside, San Bernardino and Ventura counties, covering CSLB licenses, insurance, contracts, bids, design-build vs contractor, and red flags.
JADU vs ADU in California: Size, Rules, Cost and Which to BuildThe real differences between a junior accessory dwelling unit and an ADU under California law, including the 2026 JADU owner-occupancy change, plus costs and when each makes sense.
How to Legalize an Unpermitted ADU in California (AB 2533)How California's AB 2533 amnesty rules help owners permit ADUs and JADUs built without permits before 2020, what cities can and cannot require, and the steps to legalize.
Prefab and Modular ADUs in California: Real Costs, Permits and PitfallsHow prefab, modular, panelized and manufactured ADUs are permitted in California, what they really cost installed in Southern California, and how to compare them with site-built.
SB 9 vs ADU: Lot Splits, Duplexes and Backyard Units in CaliforniaHow California's SB 9 duplex and urban lot split law compares with building an ADU, including owner-occupancy affidavits, minimum lot sizes, unit caps and which path fits your goals.
Two-Story and Above-Garage ADUs in California: Height Rules, Costs and DesignWhen California law lets you build a two-story or above-garage ADU, the 16/18/25-foot height rules, what it costs in Southern California and design tips for small lots.