ADU Builder in Rosemead, CA: Permits, Local Rules and Costs

Does Rosemead offer pre-approved ADU plans?

Yes, under Assembly Bill 1332. The City of Rosemead Accessory Dwelling Units page on rosemeadca.gov states that Assembly Bill 1332 requires local agencies to develop a program to preapprove architectural and design plans for ADUs by January 1, 2025, that the City accepted plans from design professionals for detached ADUs pre-approved for use throughout the City, and that the program is intended to save homeowners the expense of having custom plans created and to simplify the permit process. The same page states that the program is continuous and allows additional plans to be pre-approved in the future, and that homeowners purchase the plans directly from the design professional and then submit them to the City for plan check. The page also states that modifications to a pre-approved ADU plan are not accepted for the expedited process; changes push the project into the regular ADU plan review path.

What local ordinance and chapter cover Rosemead ADUs?

The City of Rosemead Accessory Dwelling Units page on rosemeadca.gov states that on September 8, 2020 the Rosemead City Council adopted Ordinance No. 995 to comply with the new state provisions for accessory dwelling units, and that the updated Ordinance became effective on October 8, 2020. The same page states that the full text and additional requirements appear in Rosemead Municipal Code Chapter 17.30.190, and that an administrative site plan and design review must be submitted to the Planning Division prior to submitting for a Building Permit as part of the Building Plan Check process to ensure compliance with the zoning regulations. For details on a specific ADU submittal, homeowners contact the City Planning Division using the contact information posted on rosemeadca.gov.

What size limits and height rules apply to a Rosemead ADU?

The City of Rosemead Accessory Dwelling Unit Standards handout (ADU HANDOUT PUBLIC 2026 with Policy) on rosemeadca.gov, published by the Planning Division, states that for single-family dwelling units the maximum height is 17 feet for a one-story ADU and 30 feet for a two-story ADU, and that the maximum floor area for a detached ADU is 1,200 square feet if floor-area ratio permits, with 150 to 850 square feet for a studio or one bedroom and 1,200 square feet for a detached freestanding ADU that provides more than one bedroom. The handout also states that when the existing primary residence is less than 1,600 square feet, an 800 square foot ADU will be permitted. The same handout states that a JADU on a single-family lot is allowed at 500 square feet, with an 800 square foot ADU permitted alongside the JADU on site.

What setbacks and parking rules does Rosemead require?

The City of Rosemead Accessory Dwelling Unit Standards handout on rosemeadca.gov states that for single-family lots the minimum side setback is four feet and the minimum rear setback is four feet for both attached and detached ADUs, and that the minimum off-street parking is one parking space per bedroom or ADU, whichever is less. The same handout states that if the minimum distance between dwellings cannot be met, an 800 square foot ADU that is at least 16 feet in height with four-foot side and rear yard setbacks shall be permitted provided that it is constructed in compliance with all other local development standards. State law caps what a city can require: under Gov. Code 66314(d)(11), a permitting agency shall not require parking spaces to be replaced for an ADU that is part of a parking-removed conversion, and Gov. Code 66322(a) lists parking exemptions for ADUs near transit, in historic districts, and on lots with a car share vehicle.

How long does the Rosemead plan check take for an ADU?

State law sets the binding permit timeline. Under Gov. Code 66317(a)(3), a permitting agency shall approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the agency receives a completed application, and if the permitting agency has not approved or denied the completed application within 60 days the application is deemed approved. Under Gov. Code 66317(a)(2), the permitting agency must tell the applicant in writing within 15 business days whether an ADU application is complete or what items are defective or deficient. The City of Rosemead Accessory Dwelling Units page on rosemeadca.gov states that an administrative site plan and design review is submitted to the Planning Division before the Building Plan Check process for compliance with the zoning regulations.

How much does a Rosemead ADU cost from L Square?

L Square publishes configured model prices on the cost guide page: $180,000 for Model 600, $240,000 for each of Models 800A and 800B, $295,000 for each of Models 1000A and 1000B, and $354,000 for Model 1200. These are model prices, not a final lot total. Rosemead lots also carry the City planning fee, the City building permit fee, the proportional impact fee on ADUs over 750 sq ft under Gov. Code 66311.5, school district fees where the project exceeds the district threshold, and any utility and connection fees from the providers named in the City application materials. Garage conversions, attached ADUs, and JADUs are priced from a property specific scope because each one depends on the existing structure and the lot layout.

Official Rosemead ADU sources

• The City of Rosemead Accessory Dwelling Units page on rosemeadca.gov states that Assembly Bill 1332 requires local agencies to develop a program to preapprove architectural and design plans for ADUs by January 1, 2025, that the City accepted plans from design professionals for detached ADUs pre-approved for use throughout the City, and that homeowners purchase plans directly from the design professional. The same page states that on September 8, 2020 the Rosemead City Council adopted Ordinance No. 995 effective October 8, 2020, with the full text in Rosemead Municipal Code Chapter 17.30.190. Official source
• The City of Rosemead Accessory Dwelling Unit Standards handout published by the Planning Division on rosemeadca.gov (ADU HANDOUT PUBLIC 2026 with Policy) states that for single-family dwelling units the maximum height is 17 feet for a one-story ADU and 30 feet for a two-story ADU, that the minimum side setback is four feet and the minimum rear setback is four feet for both attached and detached ADUs, and that the minimum off-street parking is one parking space per bedroom or ADU whichever is less, with Owner Occupant Restriction None for single-family lots. Official source
• Gov. Code 66317(a)(3), hosted on leginfo.legislature.ca.gov, states that a permitting agency shall approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot, and that if the permitting agency has not approved or denied the completed application within 60 days, the application is deemed approved. Official source
• Gov. Code 66311.5(c)(1), hosted on leginfo.legislature.ca.gov, states that a local agency, special district, or water corporation shall not impose any impact fee upon the development of an accessory dwelling unit that has 750 square feet of interior livable space or less or a junior accessory dwelling unit that has 500 square feet of interior livable space or less, and that any impact fees charged for an ADU of more than 750 square feet shall be charged proportionately in relation to the square footage of the primary dwelling. Official source