ADU rules in Placentia

Can I add an ADU to my property?

An ADU is a separate home with its own kitchen and bathroom. You can build one in the backyard, attach it to your home, or convert suitable existing space, such as a garage.

California allows ADUs on qualifying residential lots with an existing or proposed home. The Placentia City Planning Division can help with the requirements for your property.

How big can my ADU be?

Local size limits must allow at least 850 square feet for a studio or one-bedroom ADU, and 1,000 square feet for an ADU with two or more bedrooms. How much you can build also depends on the space available and the rules for your site.

California separately protects a qualifying detached ADU of up to 800 square feet, even when some local lot-coverage or yard rules would otherwise prevent it.

These are statewide protections, not the maximum size for every property. Front yards, easements and the type of ADU can affect where a larger design fits.

Official guidance

Can I convert my garage, and do I need parking?

A garage can become an ADU if it meets the requirements for living space. You do not have to replace parking lost when a garage or carport is converted or removed for an ADU.

Many ADUs need no extra parking. California exemptions include ADUs within a half-mile walk of public transit and qualifying conversions of existing space. If no exemption applies, the City can generally require no more than one space per ADU or bedroom, whichever is less.

Official guidance

Are pre-approved plans available?

Pre-approved plans are ADU designs the City has already reviewed. You still need a permit and drawings showing how the design fits your property.

Call the Placentia City Planning Division at 714-993-8124 to ask about available pre-approved ADU plans.

How do I get a permit?

1. Describe your project.Contact the Placentia City Planning Division with your address, the type of ADU and its approximate size.
2. Prepare and submit the plans.Prepare the ADU/JADU checklist documents and apply to Planning in person or through the SmartGov portal.
3. Respond to plan-review comments.Your designer makes any required corrections. Obtain the building permit before construction starts.
4. Build and complete inspections.Arrange the required inspections as work progresses. Obtain final approval before anyone moves in.

City application information

How long does review take, and what fees apply?

For a standard ADU application, the City has 15 business days to say whether the application is complete. The usual decision deadline is 60 days after a complete application. A new main home submitted at the same time, or a delay you request, can change that timing.

An ADU with 750 square feet of interior living space or less is exempt from local impact fees, which fund public facilities. Plan-review, building-permit, utility and some school charges can still apply.

Water, sewer, electrical service and fire access are reviewed for the site. An ADU does not require sprinklers when the main home is not required to have them.

Official guidance

Can I rent out my ADU?

You can use an ADU for family or rent it as a home. For a regular ADU, the City generally cannot require you to live on the property. For a JADU that shares the main home's bathroom, owner occupancy is required.

Plan for long-term housing. State-exempt ADUs and JADUs require rental terms longer than 30 days; other ADUs also need to meet the City's rental rules.

Use rent estimates for similar homes in Placentia when comparing potential income.

Try the ADU Rental Calculator

Official guidance

Helpful resources