ADU design
ADU plans for sale: what you are actually buying
By the HyreADU research desk. Last checked .
The short answer
ADU plans for sale are usually a license to build one copy of a design, not a permit-ready set for your lot.
Some cities list designer-owned plans they have preapproved; Los Angeles lists them for purchase from the plan owner, and San José lists approved plans from five vendors.
Any plan still needs a site plan, energy forms and often engineering for your site.
What a purchased plan usually includes
- Floor plans, elevations, sections and details for the building.
- A license to build it once, at one address.
- Sometimes structural calculations and energy compliance for a typical site.
What you still need
- A site plan showing your lot, setbacks and utilities.
- Energy compliance for your orientation and climate zone.
- Engineering for your soil, wind and seismic conditions where required.
- A permit application, and in many cities a designer or contractor to submit it.
City-listed plans vs online stock plans
A plan on a city’s preapproved list has passed that city’s code review for the current code cycle, and in California a detached ADU using one gets a 30-day decision (Gov. Code § 65852.27).
A stock plan bought online has passed no review in your city. Torrance says its listed plans are about 80 percent complete for permitting, and San José advises that the vendor or contractor pull the permit. See ADU plans for program links.
A mistake to avoid
The mistake to avoid is buying a plan from another state or code cycle.
A plan drawn for the 2022 California code may not pass under the 2025 code that took effect January 1, 2026, and a plan from out of state may not meet California energy rules at all. Ask which code edition the plan was drawn to.
What to do next: check your lot with the ADU feasibility checker, read the questions to ask an ADU builder, then tell us about your project. Matching is not live yet, so we reply with information, not a quote.
Get ADU optionsQuestions
How much do ADU plans cost?
We publish no prices. Some city plans are free; designer plans are priced by their owners.
Can I modify a purchased plan?
The license and the city program decide. Changes to a preapproved plan can void its preapproval.
Who submits the permit?
You, your designer or your contractor. Some cities advise the vendor do it.
Are online plans permit-ready?
Not for your lot until your city reviews them with your site plan.
Sources
- LADBS, ADU Standard Plan Program. Checked September 5, 2026.
- City of San José, Preapproved ADUs. Checked September 5, 2026.
- Gov. Code § 65852.27 (preapproved ADU plan programs, AB 1332). Checked September 5, 2026.
- California Energy Commission, 2025 Building Energy Efficiency Standards (Title 24, Part 6). Checked September 5, 2026.
- City of Torrance, Pre-Approved ADU Program. Checked September 5, 2026.
- HyreADU research: pre-approved ADU plans in California. Checked September 5, 2026.
HyreADU is a publisher. It does not design, permit or build ADUs, has no partner builders, and gives no legal, tax, lending or engineering advice.
Rules vary by state and city; California rules are labeled as such. Spotted an error? Tell us through our corrections page. Licensed professionals can also contribute as named sources.