Monterey Park Zoning and ADU Guide for Homeowners

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team.

If you own a house in Monterey Park and are thinking about a backyard cottage, a garage conversion or a junior unit inside the home, or you are about to sell a property that already has an extra unit, the City’s accessory dwelling unit (ADU) standards decide what is allowed and what a buyer can legally use.

This guide summarizes the City’s June 2026 ADU development standards sheet and the state law it cites, in plain language, so you know where you stand before you build or list.

Monterey Park ADU standards at a glance

Topic	JADU	Attached ADU	Detached ADU	Converted ADU
Maximum interior size	500 sq ft	50 percent of the primary dwelling’s floor area or 800 sq ft, whichever is greater	1,200 sq ft	See attached or detached
Maximum height	Existing	25 ft	16 ft (18 ft in certain transit-proximity cases)	Existing
Side and rear setbacks	Existing	4 ft side, 4 ft rear	4 ft side, 4 ft rear	Existing setbacks if built in the same location
Parking per the City’s sheet	0	1 per unit	1 per unit	0

These figures come from the City’s ADU development standards sheet, which cites Monterey Park Municipal Code Chapter 21.50 and California Government Code sections 66310 through 66342. The sheet also cites state provisions that can override a local limit, such as the 18-foot height allowance for a detached ADU within a half-mile walking distance of a major transit stop, so check with Planning before you finalize a design.

The four ADU types explained

Junior ADU (JADU)

A JADU is a small unit of up to 500 square feet created from space inside the existing primary dwelling, and the City’s sheet says this includes an attached garage. Because it is created inside existing walls, height and setbacks stay as they are.

A JADU needs Planning approval, plan check and a building permit. The City’s sheet states that owner occupancy is required, in the primary residence or the JADU, if the JADU does not have its own bathroom.

Attached ADU

An attached ADU shares a wall or structure with the main house. The City allows up to 50 percent of the primary dwelling’s floor area or 800 square feet, whichever is greater, at a height of up to 25 feet, with 4-foot side and rear setbacks.

Detached ADU

A detached ADU is a separate structure, such as a backyard cottage. The sheet lists a maximum of 1,200 square feet, a 16-foot height limit and 4-foot side and rear setbacks. In the transit-proximity situation described in Government Code section 66321(b)(4), a detached ADU may go up to 18 feet.

Converted ADU

A converted ADU turns existing space, such as a garage, into a unit. The City’s sheet says existing setbacks and height are kept if you build in the same location, and the size follows whether the converted space is attached or detached.

Design standards and owner occupancy

Attached and detached ADUs must meet the development standards in Monterey Park Municipal Code section 21.08.080, including design criteria: the ADU must be architecturally compatible with the primary building in color, materials, roof type and pitch, and scale.

Owner occupancy is not required for attached or detached ADUs on the City’s sheet; it applies to JADUs without their own bathroom. Always confirm current rules with Planning, because state ADU law changes often.

Parking and fees

The City’s sheet lists one parking space per attached or detached ADU and none for a JADU or conversion, and it cites Government Code section 66322(a), which sets exceptions to parking requirements under state law. Ask Planning whether an exception such as proximity to transit applies to your lot.

On fees, the City’s 2026-2027 plan check and permit fee schedule states that single-family house additions, alterations and ADUs under 750 square feet are exempt from the development impact fee, which is otherwise $12,387 per detached dwelling unit and $11,324 per attached dwelling unit.

Plan check fees start at a $283.33 minimum per trade, and school district and sanitation district fees may also apply. See the building permits guide for the full fee list.

The ADU process, step by step

1. Confirm your lot. Check zoning, lot lines, easements, utilities and any overlay or hillside conditions.
2. Choose a type. Decide among a JADU, an attached unit, a detached unit or a conversion, using the table above.
3. Prepare plans. Include site plan, floor plans, elevations, structural and energy details.
4. Submit for Planning approval and plan check. Planning confirms the unit meets the development standards, then plan check reviews the construction details. State law generally requires ADU applications to be reviewed ministerially within a set number of days after a complete application, so ask Planning for the current timeline.
5. Complete the ADU housing questionnaire. The City must report ADU and JADU development data to the State each year and publishes an ADU housing questionnaire for applicants.
6. Build and pass inspections. Request inspections through Accela Citizen Access or the City’s inspection line, and finish with a final inspection.

Zoning questions that affect your sale

• Is the second unit permitted? A unit without a finaled permit is the most common problem for sellers.
• Is the garage still a garage? Conversions made without permits can trigger corrections.
• Do you have R-1 limits? The City publishes residential development guidelines for R-1 zones, including garage and setback rules.
• Is a rental allowed? Confirm rental rules with Planning before you describe the unit to buyers as income property.

ADUs and selling your Monterey Park home

A permitted ADU can add value, but only if it is finished and documented. Buyers, lenders and appraisers look for permit numbers and final inspection sign-offs.

Before you list, gather permits and final approvals, plans, the ADU housing questionnaire if you filed one, and a written list of any work done without a permit.

If something is missing, you can bring the work into compliance with the City, which costs time and money, or you can sell the property as-is.

How to sell a house in Monterey Park with an ADU or unpermitted unit

1. Gather what you have. Collect permits, plans and any City correspondence.
2. Decide: fix or sell as-is. Compare the cost and timeline of permitting against a direct sale.
3. Request a cash offer. Share the address and a description of the extra unit using the form on this page. We buy houses as-is in Monterey Park, including homes with permitted ADUs, unpermitted conversions and backyard units.
4. Close on your timeline. You choose the date, with no commissions and no repairs required.

Related Monterey Park guides: building permits and code enforcement. See also we buy houses in Monterey Park.

Frequently asked questions

How big can an ADU be in Monterey Park?

The City’s June 2026 standards sheet lists up to 1,200 square feet for a detached ADU, up to 50 percent of the primary dwelling’s floor area or 800 square feet (whichever is greater) for an attached ADU, and 500 square feet for a JADU.

What are the ADU setbacks in Monterey Park?

Attached and detached ADUs have 4-foot side and rear setbacks on the City’s sheet. JADUs and conversions in the same location keep existing setbacks.

How tall can a detached ADU be?

The City’s sheet lists 16 feet for a detached ADU, and cites state law allowing 18 feet in certain cases within a half-mile walking distance of a major transit stop.

Do I have to live on the property if I build an ADU?

Not for attached or detached ADUs on the City’s sheet. A JADU requires owner occupancy in the primary residence or the JADU if the JADU does not have its own bathroom.

Are ADUs exempt from impact fees?

The City’s fee schedule exempts ADUs under 750 square feet from the development impact fee. Other fees, including plan check, school and sanitation fees, may still apply.

Can I sell a Monterey Park house with an unpermitted unit?

Yes. You can sell as-is to a cash buyer without legalizing the unit first. A traditional buyer may ask for permits or repairs, which is why many owners request a cash offer instead.

More guides

• Monterey Park Building Permits Guide
• Monterey Park Code Enforcement Guide
• We Buy Houses in Monterey Park
• We Buy Houses in Los Angeles County
• All California Guides

Sources

• City of Monterey Park, ADU Development Standards (June 2026)
• City of Monterey Park, ADU application and housing questionnaire
• City of Monterey Park, Residential Development Guidelines (R-1)
• City of Monterey Park, Plan Check and Permit Fees effective July 1, 2026

This guide is general information from public sources, not legal advice. Confirm current rules with the city.