Murrieta Zoning and ADU Guide for Homeowners and Sellers

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team. Information comes from the City of Murrieta; sources are listed at the end.

Murrieta allows an accessory dwelling unit (ADU) by right with a building permit when the city’s conditions are met, and the city’s Information Bulletin IB-108 summarizes them. The bulletin says it follows the State ADU rules the city has adopted.

Murrieta ADU rules at a glance

What does Murrieta require for an ADU?

According to the bulletin, the property needs an existing main residence, or the ADU is built at the same time as one. The ADU must be attached to the main home, or detached on the same legal lot.

It must meet the California Residential Code for efficiency dwelling units, with a living room of at least 220 square feet and 100 more for each occupant beyond two. It must look architecturally compatible with the main home, and no variances are granted for ADUs.

Setbacks depend on the residential zone, so the city tells owners to confirm the zoning and exact setbacks for their property.

Setbacks, parking and fees

The bulletin says no setback is required for an existing legal garage or accessory structure converted to an ADU, and an ADU above a garage needs a 5-foot setback. A new ADU needs one parking space on site, which can be an uncovered driveway space or a tandem space.

No extra parking is required if the ADU is within half a mile of public transit, in a historic district, in an area where on-street permits are required but not offered to the occupant, within one block of a car-share area, or part of the existing home or an existing accessory structure.

For a garage conversion, replacement parking for the main home must be shown with the application as state law applies. Converted existing structures with the right meter size are not subject to additional water and sewer fees.

Guest houses, park models and other structures

The city separates an ADU, which has its own kitchen and bathroom and may be rented, from guest living quarters, which have no kitchen or wet bar, are regulated as accessory structures and may not be rented. It also says park model trailers are not allowed for permanent use on private property because state law treats them as recreational vehicles.

How an ADU affects selling a house in Murrieta

The bulletin says a property with an active code enforcement violation does not qualify for an ADU. An unpermitted unit also raises questions with buyers, appraisers and lenders, and sellers in California generally have to disclose known problems. A cash buyer can purchase the property with the unit as it stands and price the risk into the offer.

How to sell a house in Murrieta with an unpermitted unit

1. Confirm what exists. Note any guest house, garage conversion or added kitchen or bathroom.
2. Ask the city. The Building & Safety Division can be reached at 951-304-2489.
3. Weigh the options. Legalize it, sell with a credit, or sell as-is.
4. Disclose honestly. A cash offer removes repairs and inspections from the timeline but not disclosure duties.

We buy Murrieta houses as they are. See our Murrieta cash home buyer page for how it works.

Have an ADU or guest house and a decision to make? Call (424) 435-2326 or request a cash offer. There is no cost and no obligation.

Murrieta ADU FAQ

How big can an ADU be in Murrieta?

An attached ADU can be up to 50% of the main home’s floor area, up to 1,200 square feet. A detached ADU can be up to 1,200 square feet.

Can I rent a Murrieta ADU?

Yes, but not as a short-term rental of 30 days or less, according to the city bulletin.

Can I build an ADU with an open code violation?

No. The bulletin says the property must not have an active code enforcement violation.

Can I sell a Murrieta house with an unpermitted unit?

Yes. It does not legally stop a sale, but it can slow a traditional one. A cash buyer can purchase the property as-is.

Sources

• City of Murrieta: Information Bulletin IB-108, Accessory Dwelling Units
• City of Murrieta: Building & Safety Division

This guide is general information, not legal advice. Rules change; confirm requirements with the City of Murrieta.