How much does an ADU permit cost in Santa Monica?

All-in permit-related costs typically run $5,000–$15,000 (Andalusia Drafting 2026; Dynamic Quality Builders 2026). This includes building permit fees, plan check, and professional soft costs. Impact fees may apply for ADUs over 750 sq ft.

Do I need to replace parking when building an ADU in Santa Monica?

No — California state law eliminates parking-replacement requirements for ADUs within half a mile of public transit, in historic districts, in existing structures (garage conversions), or where on-street parking permits aren't required. Most Santa Monica ADUs qualify for at least one of these exemptions.

ADU permits · Santa Monica, California

Santa Monica ADU permit fees, timeline, and rules

Q: How long does an ADU permit take in Santa Monica?

Typically about 22 weeks from complete application to approval. NOTE: SB 1077 (California Coastal Commission ADU guidance) in active development through 2026 - Coastal permitting may shift mid-project. Santa Monica fees ~1-2% of construction valuation per FY26 schedule (Aug 2025). Coastal Zone covers most of city west of Lincoln Blvd south of Pico, west of 4th north of Pico - requires Coastal Development Permit (CDP), adds 2-4 months and $13,000+ project cost. Coastal surcharge +0.65% on planning fees. Architectural Review Board (ARB) Administrative Design Approval ~$3,500 when triggered. Modification to Approved ADU Permit $552 per change. Impact fees waived under 750 sq ft per state preemption. Aggressive seismic standards (post-Northridge) add $2,500-$7,500 in engineering. Older housing stock (median 1967, 13% pre-1940) triggers panel upgrades $3K-$8K and lead/asbestos $2K-$15K. Landmarks Commission review adds 20-30% to exterior. Coastal material upcharge ~10-15% premium on exterior. UNIQUE: up to 8 detached ADUs allowed on Multiple-Unit Dwelling (MUD) parcels. Sizing: 850 sq ft studio/1BR, 1,200 sq ft 2+ BR per SMMC 9.31.025.

Sourced permit fee ranges, typical approval timelines, and the ADU-specific rules that apply in Santa Monica. All numbers cross-referenced against published builder data and the city's planning department.

Last validated by OwnAdu: May 26, 2026 (manually verified)

Looking for the full Santa Monica ADU guide — cost, financing, ROI?See it here

Typical permit fees (all-in)

$5,000 – $15,000

Typical approval timeline

~22 weeks

Maximum ADU size

1,200 sq ft

Parking replacement required

No — exempt under state law in most cases

Owner-occupancy required

Setback requirements

4 ft side/rear for new detached (state); 0 ft for conversions; front per underlying zone.

What's distinctive about this jurisdiction

NOTE: SB 1077 (California Coastal Commission ADU guidance) in active development through 2026 - Coastal permitting may shift mid-project. Santa Monica fees ~1-2% of construction valuation per FY26 schedule (Aug 2025). Coastal Zone covers most of city west of Lincoln Blvd south of Pico, west of 4th north of Pico - requires Coastal Development Permit (CDP), adds 2-4 months and $13,000+ project cost. Coastal surcharge +0.65% on planning fees. Architectural Review Board (ARB) Administrative Design Approval ~$3,500 when triggered. Modification to Approved ADU Permit $552 per change. Impact fees waived under 750 sq ft per state preemption. Aggressive seismic standards (post-Northridge) add $2,500-$7,500 in engineering. Older housing stock (median 1967, 13% pre-1940) triggers panel upgrades $3K-$8K and lead/asbestos $2K-$15K. Landmarks Commission review adds 20-30% to exterior. Coastal material upcharge ~10-15% premium on exterior. UNIQUE: up to 8 detached ADUs allowed on Multiple-Unit Dwelling (MUD) parcels. Sizing: 850 sq ft studio/1BR, 1,200 sq ft 2+ BR per SMMC 9.31.025.

Source: https://www.santamonica.gov/media/Document%20Library/Topic%20Explainers/Planning%20Resources/MUD-Parcel%20ADU%20Guide_11-25.pdf

Buying a home with an ADU in California?

State law, typical premium, what to verify on a permitted ADU, and what to do if you find an unpermitted one.

Californiabuyer's guide →

Get a real quote for your Santa Monica project

Run the cost calculator with Santa Monica selected to see how local permit fees and timelines affect your all-in budget, or get matched with builders who specialize in Santa Monica ADUs.

Open the cost calculator See builders in Santa Monica

Other California cities

Related resources

Get sourced ADU permit updates monthly

Permit fees and timelines change. We re-validate against the source URL above each quarter.

Santa Monica ADU permit fees, timeline, and rules

Last validated by OwnAdu: May 26, 2026 (manually verified)

Looking for the full Santa Monica ADU guide — cost, financing, ROI?See it here