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

How many ADUs can an Arcadia single family lot have?

The City of Arcadia ADU Flyer, hosted on arcadiaca.gov, lists the three choices the city allows on a single family lot: one attached ADU, one detached ADU by itself, or one detached ADU together with one JADU. The Arcadia Development Code Section 9102.01.080 (Accessory Dwelling Units), hosted on arcadiaca.gov as a PDF, sets the same choices and the same lot coverage and FAR limits. A JADU on a single family lot cannot be combined with an attached ADU. The state 60 day clock in Gov. Code 66317(a)(3) still applies to the ADU permit, so a completed application that the city does not approve or deny within 60 days is deemed approved.

What is the Arcadia Pre-Approved ADU (PAADU) program?

The Pre-Approved Accessory Dwelling Unit (PAADU) page, hosted on arcadiaca.gov, says the City is accepting applications from design professionals to have plans for detached ADUs pre-approved for use throughout Arcadia, and the program applies to detached ADUs only (not attached ADUs, JADUs, or conversions). The page lists the homeowner benefits: no Planning Review (a cost savings of $696), expedited plan check in Building, and the ability to select the best design that fits the property. The page also states that pre-approved plans may not be used for sites in the Very High Fire Severity Zone (VHFSZ) unless the plan was specifically designed with alternative details for the VHFSZ, and that the applicant still needs a site plan and a completed PAADU Submittal Checklist. The homeowner's ADU building permit application, including supporting plans and documents, is accepted online through the Arcadia EDGE e-permit portal.

What are the size, height and setback rules for an Arcadia ADU?

The Arcadia Development Code Section 9102.01.080, hosted on arcadiaca.gov as a PDF, sets the size and setback standards. An ADU subject to a Zoning Clearance Permit (a detached ADU above 800 sq ft in floor area, or any attached ADU) caps floor area at 850 sq ft for a studio or one-bedroom unit and 1,000 sq ft for a unit with two or more bedrooms, with a minimum side and rear yard setback of four (4) feet. A detached ADU may not exceed one story, and a second story or two-story attached ADU may not exceed the height of the primary residence. A detached ADU is limited to 16 feet in height under the same code section, with up to 18 feet allowed within a half mile of certain transit corridors, and up to 25 feet or the primary residence height limit (whichever is lower) for an attached ADU. The City of Arcadia ADU Flyer adds that a detached ADU of 800 sq ft or less that complies with the 4 foot side and rear setbacks and the height limits is allowed with a Building Permit only, with no Zoning Clearance Permit (Planning Review) required.

What does an Arcadia ADU permit cost?

The City of Arcadia ADU Flyer, hosted on arcadiaca.gov, separates the permit paths by project type. Detached ADUs that are 800 sq ft or less and meet the 4 foot setbacks and height limits, converted ADUs from within the walls of the primary single-family dwelling (up to 50% of the existing home floor area), and JADUs of 500 sq ft or less are allowed with a Building Permit only. Detached ADUs greater than 800 sq ft and all attached ADUs need a Zoning Clearance Permit (Planning Review) first, and a building permit is then required upon approval. State law in Gov. Code 66311.5(c)(1) caps impact fees for an ADU of 750 sq ft or less at zero and charges larger ADUs proportionally to the primary dwelling square footage. L Square collects the live Arcadia fee amounts from the city current application materials before submittal so the homeowner sees the total.

How long does an Arcadia ADU permit take?

The state clock in Gov. Code 66317(a)(3) gives a permitting agency 60 days from a completed application to approve or deny it, and an application the city does not act on within 60 days is deemed approved. The Arcadia Development Code Section 9102.01.080, hosted on arcadiaca.gov, requires the city to provide notice of the denial and corresponding comments within the 60 day time period, and treats the demolition permit for a detached garage replaced with an ADU as reviewed and issued at the same time as the ADU permit. The Pre-Approved ADU (PAADU) page adds that the program waives Planning Review for the homeowner, leaving Building plan check and inspections as the remaining city steps.

How much does an ADU cost in Arcadia?

L Square publishes configured model prices on the cost guide page: $180,000 for Model 600, $240,000 for Models 800A and 800B, $295,000 for Models 1000A and 1000B, and $354,000 for Model 1200. These are model prices, not a final total for a specific lot. Arcadia lots also carry the city application fee, the plan check fee through Arcadia Building Services, 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 Arcadia ADU sources

• The City of Arcadia ADU Flyer, hosted on arcadiaca.gov as a PDF, lists the three options for a single family lot (one attached ADU, one detached ADU, or one detached ADU with one JADU), the four Building-Permit-Only paths (converted ADU up to 50 percent of existing home floor area, JADU 500 sq ft or less, detached ADU 800 sq ft or less meeting 4 foot setbacks, conversion of non-livable space in multi-family), and the Zoning Clearance Permit requirement for detached ADUs over 800 sq ft and all attached ADUs. Official source
• The Pre-Approved Accessory Dwelling Unit (PAADU) page, hosted on arcadiaca.gov, says the City accepts applications from design professionals to have detached ADU plans pre-approved for use throughout Arcadia, with the homeowner benefit of no Planning Review (a cost savings of $696), expedited plan check in Building, and the restriction that pre-approved plans may not be used for sites in the Very High Fire Severity Zone unless designed with alternative details. Official source
• The Arcadia Development Code Section 9102.01.080, hosted on arcadiaca.gov as a PDF, sets size standards (850 sq ft studio or 1 bedroom, 1,000 sq ft two or more bedrooms), a 4 foot side and rear setback, a one story cap on detached ADUs, a 16 foot detached height limit (18 feet within half a mile of certain transit corridors, 25 feet or primary residence height whichever is lower for attached ADUs), and the 60 day notice-of-denial rule for the city. Official source
• Gov. Code 66317(a)(3), hosted on leginfo.legislature.ca.gov, requires a permitting agency to approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the permitting agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot, and states that if the local 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
• Gov. Code 66314(d)(5), hosted on leginfo.legislature.ca.gov, states that the total floor area for a detached accessory dwelling unit shall not exceed 1,200 square feet, and Gov. Code 66314(d)(7) states that no setback shall be required for an existing living area or accessory structure or a structure constructed in the same location and to the same dimensions as an existing structure that is converted to an accessory dwelling unit or to a portion of an accessory dwelling unit. Official source
• Gov. Code 66321(c)(2)(C), hosted on leginfo.legislature.ca.gov, prohibits any local ordinance that does not permit an accessory dwelling unit with at least 800 square feet of interior livable space and with four-foot side and rear yard setbacks to be constructed in compliance with all other local development standards, and Gov. Code 66321(c)(4)(A) requires every city to allow a height of 16 feet for a detached ADU on a lot with an existing or proposed single family or multifamily dwelling. Official source