Current guidance from an Orange County design-build team on ADU costs, permits, layouts, timelines, and construction decisions.
How much does an ADU cost in Southern California? See two completed Pasadena and Rosemead projects and learn why site conditions, utilities, design and finishes matter more than...
Read article →ADU utility planning guide for Orange County and Los Angeles By Brian Leung, licensed General Contractor, CSLB #1095476 AI-generated explanatory […]
Read article →The short answer An ADU construction checklist should connect every stage to a document, a responsible person, and a clear […]
Read article →The short answer The best ADU design idea is the one that makes the property easier to live on, not […]
Read article →The short version This is a finished 700 sq ft ADU in Pasadena, CA that we designed and built — […]
Read article →The short version This is a finished 1,188 sq ft detached two-story ADU in Rosemead, CA — 3 bedrooms, 2 […]
Read article →The short version California sets the floor everywhere — ministerial approval, 4-ft side and rear setbacks, and since 2026 a […]
Read article →The short version An ADU foundation is built in layers, and every layer has a job: compacted ground, a gravel […]
Read article →Last reviewed: August 11, 2026. Planning ranges are based on contractor experience and are not city service guarantees. Rules and […]
Read article →Last reviewed: August 11, 2026. Planning ranges are based on contractor experience and are not city service guarantees. Rules and […]
Read article →The HCD Accessory Dwelling Unit Handbook is the state's plain-language guide to ADU law. What it covers, what changed in 2026, and when a homeowner needs it.
Most ADU projects in California do not need a licensed architect. See when an adu architect is required, and what to check in Orange County and Los Angeles.
An ADU with garage in Orange County can sit above, beside, or inside a garage. See the size, height, parking, permit, and fee rules that apply to each layout.
An 800 sq ft ADU in California is the state-protected small detached unit under Section 66323(a)(2). Read the 4-foot setback, 16 ft height, and fee rules.
California ADU 30-day rental rule: under Gov. Code 66323(e) and 66333(g), the shortest compliant stay is 31 nights, effective January 1, 2026.
The California ADU 60-day permit rule under Gov. Code 66317 sets the deadline for a city to approve or deny a complete ADU application.
California ADU height rules: detached 16 feet, 18 feet within half a mile of major transit, 25 feet for an attached ADU. Gov. Code 66321 and 66314.
Can an HOA restrict an ADU in California? Civil Code 4751 makes HOA bans and unreasonable restrictions void. Reasonable design standards still apply.
California ADU impact fees in 2026: state law exempts ADUs to 750 sq ft and JADUs to 500 sq ft, with proportional fees on ADUs above the 750 sq ft floor.
California ADU maximum size rules in 2026, citing Government Code sections 66321 and 66314. Detached, attached, garage conversion, and JADU square footage caps.
California ADU owner occupancy rule: a city cannot require you to live in the ADU (AB 976). AB 1033 lets cities opt in to allow separate ADU sale as a condo.
California ADU parking requirements in 2026: state law caps required parking at one space and bars replacement parking for converted spaces.
How many ADUs per lot California allows: Section 66323 sets three state-protected units on a single-family lot and up to eight detached on multifamily.
ADU rental income in California in 2026: what a permitted ADU in Orange County or LA County leases for, what drives the rent, and the owner's net calculation.
California ADU setback rules: 4-foot side and rear yard maximum, no setback on garage conversions, and the 800 sq ft protection in Gov. Code 66314 and 66321.
Garage conversion ideas for a California ADU: layout patterns, ceiling height, the four-foot setback carve-out, and the 31 night rental term in one guide.
Illegal garage conversion California: the AB 2533 path to legalize an unpermitted ADU built before 2020, the HSC 17920.3 test, and what to file.
A studio ADU in California is one open room with a bath and kitchen. See the size limits, parking and fee rules, and what a studio ADU costs in Orange County.
