About ADU Home Construction

Who publishes this site

ADU Home Construction is an educational website for California homeowners who are thinking about an accessory dwelling unit. The first pages went live in March 2026.

The guides cover planning, permits, financing, construction choices, prefab options, and renting. The aim is practical: what to ask, what to look up, and where the official rule lives.

We are not a licensed contractor, and we are not an architect, a lender, or a law firm. We do not design ADUs, pull permits, or build them. A page here is general reading for your own project. It is not a bid, a legal opinion, or advice about your loan or your lot.

If you ask for a contractor introduction, we pass along the city and project details you send. We do not vet contractors, pre-screen them, or check licenses. Before you hire anyone, confirm the license is active at the Contractors State License Board (cslb.ca.gov).

Why these guides exist

An ADU can earn rent, make room for family, or do both. The part that trips people up is the stack of state rules plus the city checklist, and both change. Read these pages before you pay for drawings or sit down with a contractor.

How we edit

Statewide legal and program claims are written from official government material. The references we use are the California Department of Housing and Community Development, the ADU sections of the California Government Code on leginfo.legislature.ca.gov, and the California Housing Finance Agency. When a guide mentions a city, treat it as a starting sketch and read that city's own ADU page before you apply. Local checklists and fees differ from town to town.

Where a page shows an Updated date, that date is the last revision we published.

See a stale fee, a closed grant, or a rule we described poorly? Email info@aduhomeconstruction.com with the page address and what looks wrong. We will correct the page and refresh the Updated date. Advertising questions can go through the contact form. Advertisers do not write or approve these guides. If we run a sponsored placement, the page will say so.

How the cost ranges are made

California does not publish one official ADU price. Dollar figures on this site are planning ranges for homeowners who are still deciding whether to request bids. We build a range from published California builder and calculator prices, then check it against current state rules on fees, building standards, and funding from HCD and CalHFA. A garage conversion, a junior ADU inside the main house, and a new detached unit fall in different bands. Utility runs, slope, and city fees often move the total more than the finishes do.

Use a range to see whether a project belongs in the conversation. Then ask contractors for written bids on your lot. The financing guide and the 2026 cost article show the ranges we are using.

What you will find here

• California explainers for planning, law, financing, construction, prefab, upkeep, and renting
• Links to HCD, the Government Code, and CalHFA when a page states a statewide rule or program
• Cost ranges labeled as planning estimates, built the way described above
• A corrections email, so a wrong fee or a closed program can be fixed in public