ADU Builder in Manhattan Beach, CA: Permits, MBMC 10.74 Rules and Costs

What Manhattan Beach ADU ordinance took effect in 2025?

On April 1, 2025 the Manhattan Beach City Council adopted Ordinance No. 25-0004, which amends MBMC Chapter 10.74 Accessory Dwelling Units. The revised regulations took effect May 1, 2025. The City is still updating the Municipal Code website, so the operative text is the relevant portion of Ordinance No. 25-0004. Ordinance No. 25-0004 also amends the City's Local Coastal Program to add local ADU and JADU regulations for the Coastal Zone, but those LCP amendments await California Coastal Commission certification. Until the CCC certifies the LCP amendments, ADUs and JADUs proposed in the Coastal Zone follow state ADU law only. The state framework cited by the City is CA Government Code Sections 66314 through 66332 for ADUs and Sections 66333 through 66339 for JADUs, and L Square confirms the operative local amendments with the Planning Division at intake.

What state ADU rules apply to a Manhattan Beach lot?

Manhattan Beach enforces the state ADU framework, with three local permit pathways layered on top. The first pathway is the state 66323 Building Permit Only for ADUs that meet the state-mandated floor, the second is the full ADU Permit for projects that need local design review, and the third is the Coastal Zone path that adds a Coastal Development Permit. State Government Code Section 66317(a)(3) gives the permitting agency 60 days from receipt of a complete application to approve or deny it, after which the application is deemed approved, and Section 66317(a)(2)(A) requires a written completeness determination within 15 business days. The City is awaiting the CCC LCP certification step, and L Square confirms the operative pathway and the local design standards with the Planning Division before any drawings are final.

What size, height, and setback rules apply to a Manhattan Beach ADU?

State Government Code Section 66314(d)(5) caps a detached ADU on a lot with an existing or proposed single-family dwelling at 1,200 square feet of floor area. Section 66321(b)(2)(A) and (B) set statewide minimum floors of 850 square feet for a studio or one bedroom detached ADU and 1,000 square feet for a multi bedroom detached ADU that a local ordinance cannot undercut. Section 66321(b)(3) requires the city to allow a minimum 800 square foot detached ADU with 4 foot side and rear yard setbacks. Section 66314(d)(7) lets the city clear existing structures and same location rebuilds from the 4 foot setback ceiling. Section 66321(b)(4) sets the height tiers at 16 feet for a detached ADU, 18 feet within one-half mile of a major transit stop or a high quality transit corridor, and 25 feet for an attached ADU, plus an additional two feet of roof pitch allowed. Section 66325(a) states that the state ADU article supersedes any conflicting local ordinance.

How does the Coastal Zone change the ADU process in Manhattan Beach?

Manhattan Beach sits partially inside the state Coastal Zone, and the Coastal Zone rules are the strictest local path. The City's Interactive Map on manhattanbeach.gov confirms whether a specific lot lies inside or outside the Coastal Zone, and the homeowner or designer should run that check before any design work begins. Until the California Coastal Commission certifies Ordinance No. 25-0004's Local Coastal Program amendments, every ADU and JADU proposed in the Coastal Zone is reviewed under state ADU law only and also requires a Coastal Development Permit on top of the building permit. Required on-site parking for the primary dwelling must be maintained at all times on Coastal Zone properties. After CCC certification, the local amendments in MBMC 10.74 will apply inside the Coastal Zone as well. L Square confirms the lot's Coastal Zone status, the current LCP amendment status, and the additional CDP step with the Manhattan Beach Planning Division before any drawings are final.

What impact fees and parking rules apply to a Manhattan Beach ADU?

California Government Code Section 66311.5(c)(1) bars a local agency, special district, or water corporation from imposing any impact fee on an ADU that has 750 square feet of interior livable space or less, and impact fees above that floor are charged proportionately in relation to the primary dwelling square footage. Section 66311.5(b) treats an ADU as not a new residential use for water and sewer connection fees, unless the ADU was constructed with a new single-family dwelling. State Section 66314(d)(11) bars the city from requiring replacement parking when a garage, carport, or covered parking structure is converted to an ADU, and Section 66314(d)(10) caps required parking at one space per ADU or per bedroom, whichever is less. State Section 66322(a) lists six situations where parking may not be imposed, including ADUs within one-half mile walking distance of public transit. State Section 66333(g) requires JADU rental terms to be longer than 30 days, so the minimum lease length on a JADU is 31 nights under the 2026 amendment. Before applying, confirm the lot's existing primary dwelling square footage, the school district boundary, and the location of any existing garage, because those items drive the site specific impact fees and the parking replacement question on this lot.

How much does an ADU cost in Manhattan Beach?

L Square's configured prefab model prices on the cost guide page run from $180,000 for Model 600, to $240,000 for Models 800A and 800B, to $295,000 for Models 1000A and 1000B, and to $354,000 for Model 1200. Those are configured model prices for the design-build path, not a final project total, and they are the same for Los Angeles County cities including Manhattan Beach. Coastal Zone properties usually carry additional review time and a separate Coastal Development Permit fee on top of the building permit fees, and the city confirms the project-specific fee total with the Planning Division at intake. Older beach lots often need pier upgrades, marine grade hardware, and Title-24 energy upgrades that are quoted after the lot review. L Square prepares the full submittal package, coordinates with the Manhattan Beach Planning Division, tracks the 60 day clock under California Government Code Section 66317(a)(3), and holds California Contractors State License Board number 1095476.

Official Manhattan Beach ADU sources

• The Manhattan Beach ADU page on manhattanbeach.gov states that on April 1, 2025 the City Council adopted Ordinance No. 25-0004 amending MBMC Chapter 10.74, effective May 1, 2025, that Ordinance No. 25-0004 also amends the Local Coastal Program, that those LCP amendments await California Coastal Commission certification, and that until CCC certification ADUs and JADUs in the Coastal Zone follow state law only. The page cites CA Government Code Sections 66314 through 66332 for ADUs and 66333 through 66339 for JADUs. Official source
• California Government Code Section 66317(a)(3) gives the permitting agency 60 days from receipt of a complete application to approve or deny it, after which the application is deemed approved. Section 66317(a)(2)(A) requires a written completeness determination within 15 business days. Official source
• California Government Code Section 66314(d)(5) limits a detached ADU on a lot with an existing or proposed single-family dwelling to 1,200 square feet of floor area. Section 66314(d)(7) lets the city clear existing structures and same location rebuilds from the 4 foot setback ceiling. Section 66314(d)(10) caps required parking at one space per ADU or per bedroom, whichever is less. Section 66314(d)(11) bars a local agency from requiring replacement parking when a garage, carport, or covered parking structure is converted to an ADU. Official source
• California Government Code Section 66321(b)(2)(A) and (B) set statewide minimum floors of 850 square feet for a studio or one bedroom detached ADU and 1,000 square feet for a multi bedroom detached ADU that a local ordinance cannot undercut. Section 66321(b)(3) requires the city to allow a minimum 800 sq ft detached ADU with 4 ft side and rear yard setbacks. Section 66321(b)(4) sets the detached ADU height ceiling at 16 ft, 18 ft near a major transit stop, and 25 ft for an attached ADU. Official source
• California Government Code Section 66311.5(c)(1) bars a local agency, special district, or water corporation from imposing any impact fee on an ADU that has 750 square feet of interior livable space or less, and impact fees above that floor are charged proportionately in relation to the primary dwelling square footage. Section 66311.5(b) treats an ADU as not a new residential use for water and sewer connection fees, unless the ADU was constructed with a new single-family dwelling. Official source
• California Government Code Section 66325(a) states that except as provided in subdivision (b) the state ADU article shall supersede a conflicting local ordinance. Official source
• California Government Code Section 66333(g) requires that a rental of a junior accessory dwelling unit be for a term longer than 30 days. Section 66333(d) requires a permitted JADU to be constructed within the walls of the proposed or existing single-family residence, with attached garages considered part of the residence. Official source