What is a pre-approved plan? #
A pre-approved plan has been created by an architect or designer and then reviewed and approved for building code compliance by a jurisdiction or, in the case of prefabricated ADU units, by a state or federal agency. Elements that are not specific to a certain property or site layout can be reviewed and approved ahead of time. Pre-approved plans still require site planning and site-specific permitting. In other words: all pre-approved plans require additional permit applications.
The pre-approval process looks different in every jurisdiction. We recommend reaching out to the Planning and/or Building Departments for an individual jurisdiction to get the application, checklist, and/or other materials they have for pre-approval.
What is a pre-designed plan? #
A pre-designed plan is a site-built plan that has already been created by an architect or designer and is ready for site customization and then the permit process. These plans have not been pre-approved. Most of the pre-designed plans in our database have been permitted previously, and many have been built at least once.
How do I apply for pre-approval? #
In California, as of January 1, 2025, every jurisdiction will be required to review any ADU plan submitted for pre-approved status if requested, either with or without a location. Designers can:
- Submit a complete permit application to any jurisdiction(s) for a specific project and request it also be reviewed as a pre-approved plan
- Submit a complete permit application to any jurisdiction(s) for a project with no location and request it be reviewed as a pre-approved plan
- Be invited by a jurisdiction to customize an existing plan to their specifications, which is then made available as a pre-approved plan.
If you have a plan pre-approved in one location, another jurisdiction may ask if they can include it as pre-approved in their location as well, without undergoing an application process (this is allowed by state law).
How do I mark a plan as pre-approved in the Plan Gallery? #
Note that we currently allow 10 activated plans per designer account, by default. If you need more to accommodate locally pre-approved plans, contact us at designer@aduaccelerator.org to increase your limit.
If your site-built plan has been pre-approved by a jurisdiction (city or unincorporated county), you can add that location in Step 2: Pre-Approval while creating or editing your listing (see Adding and Activating a New Plan Listing or Editing and Reactivating Plan Listings). See Step 2: Fill in pre-approval details for full details on adding a pre-approval location.
When you activate a plan with a new pre-approval location added, the jurisdiction(s) you added will be notified if they have a gallery. They will be asked to sign into their account and confirm the pre-approval in their portal. The plan will then show as pre-approved on their gallery.
If you are adding a prefabricated ADU plan, you are required to submit your state or federal certification details when you add the plan. This plan will now show as pre-approved any time it is added to a local gallery.
How do I get my prefabricated plan certified by state or federal agencies? #
If your ADU is classified as manufactured housing, it must be certified and inspected by the the United States Department of Housing and Urban Development (HUD). HUD defines these as follows:
“HUD Code manufactured homes are portable homes completely constructed in a factory. This type of home is built on a nonremovable steel frame and transported to its final destination with minimal on-site assembly required. HUD Code manufactured homes must comply with a single national standard defined by HUD that ensures the quality, safety, and energy efficiency of these homes.” -Source: Single-Family Site-Built, HUD Code Manufactured, and Factory-Built Homes Brief
If your ADU is classified as factory-built or modular, it must be certified and inspected by the California Department of Housing and Development (HCD). HCD defines factory-built housing (FBH) and components as:
“FBH are residential structures manufactured wholly or partially offsite, in sections, or building components which are assembled at the installation site to form part of, or most of a completed unit. FBH components may consist of wall, floor or roof panels utilizing rigid foam insulation enclosed by interior and exterior sheathing materials (structural insulated panels); or may be a conventionally framed closed-system wall or roof panel containing the plumbing, electrical, and other systems enclosed within interior and exterior panels. FBH components do not include appliances or equipment such as heaters, stoves, refrigerators or air conditioners, which have been listed and labeled by a nationally recognized testing and listing agency. FBH units and building components are generally assembled in factories located in or outside of California.” -Source: Factory-Built Housing Handbook for Local Enforcement, Agencies, Builders, and the General Public
For both of these types of prefabricated plans, you should have received a stamp of approval on your plan set from the certifying agency. We require the identifying number on that stamp to confirm your plan as certified prefabricated. This is sometimes referred to as an HUD Code, or an HCD Insignia number.
What if my prefabricated plan isn’t certified by HUD or HCD? #
If your plan utilizes Structural Insulated Panels (SIPs) or another form of panelized process, it likely requires building inspection in the jurisdiction it is being built in. Because of this, we recommend classifying those plans as “site-built”.
If your prefabricated ADU plan falls outside of the categories listed above (manufactured, factory-built/modular, or panelized/SIPs), please get in touch with us at designer@aduaccelerator.org.
Can my plan show up as pre-approved in areas I don’t designate? #
If you select “No, include my plans only where they’ve been pre-approved” then your plan will only appear where it has been pre-approved.
However, according to state law, a jurisdiction can decide that another location’s pre-approved plans work for them as well and add it to their own list of pre-approved plans. For example: Anytown has pre-approved your plan, and Cityville decides that Anytown’s pre-approval standards work for them as well. They can add your plan to their list of pre-approved plans.
