New Detached ADU in Santa Monica - One Fixed Price, Permits Handled

Fast, Reliable New Detached ADU Across Santa Monica

A new detached ADU in Santa Monica typically costs $380,000-$680,000 all-in, from permit set through final inspection, with most projects requiring 12-18 months due to the city’s dual-approval process. We’re Nadia Ellery’s team at Ellery ADU Studio Los Angeles, and we’ve designed, permitted, and built ADUs in Santa Monica since 2015 - every one at a written price before any work started, per Haven Standard Clause 1. Dispatch and scheduling run from our Los Angeles office, but our crews serve Santa Monica neighborhoods directly, and we know the difference between a build that passes inspection and one that survives the coast. Call (424) 551-7706 to schedule your free estimate.

Call (424) 551-7706

Why Ellery ADU Studio Los Angeles Is Santa Monica’s Preferred New Detached ADU Company

We’ve completed more than 900 ADUs across Los Angeles County since 2015, and Santa Monica accounts for a significant share of our portfolio - not because it’s easy, but because the regulatory complexity here filters out contractors who treat ADUs like standard backyard sheds. Our Santa Monica clients receive the same documentation every Ellery customer gets: a written price before signing, a documented photo record on every site visit, and the 365-Day Done Right Promise backed in writing.

Response time matters less for ADU construction than permit accuracy, but when Santa Monica homeowners call (424) 551-7706, a live person answers 24/7 - no voicemail queue, no callback that doesn’t materialize. We coordinate site visits from our Los Angeles office, typically scheduling initial consultations within one week for Santa Monica properties.

What separates us from out-of-area contractors is local fluency with Santa Monica’s specific failure modes. We’ve replaced too many inland-spec builds that rotted through in five years because the original contractor didn’t account for salt air. Our New Detached ADU team specifies coastal-grade materials as standard, not upsells.

Our New Detached ADU Services in Santa Monica

Custom Built ADU

Custom built ADUs in Santa Monica run $420,000-$680,000 all-in, reflecting the dual-approval timeline and coastal-spec material package we specify for every project. We design to your lot’s specific constraints - setback variances, utility routing, and the Coastal Development Permit requirements that shape what Santa Monica Building & Safety will approve. Our permit set is the core product, not an afterthought: engineered drawings, Title 24 energy calculations, and the full documentation package for both Planning & Community Development and Building & Safety review. Every custom project is quoted at a written price before any work begins, per Haven Standard Clause 1.

Prefab ADU Installation

Prefab ADU installation in Santa Monica typically ranges $380,000-$520,000, including the unit, foundation, utility connections, and all permit fees. We specify and coordinate systems from Abodu, Cover, and Dvele - brands whose envelope details we’ve vetted for coastal performance. The critical detail most Santa Monica homeowners miss: prefab units ship with standard hardware packages, and someone has to specify the stainless connectors, sealed paver joints, and marine-grade flashing that salt air demands. We handle that specification within the same single contract, so the designer and builder can’t point at each other when a fastener corrodes through in year three.

Modular ADU

Modular ADUs in Santa Monica fall in the $400,000-$560,000 range, with factory-built modules craned onto a site-built foundation. The modular approach compresses the construction schedule, but it doesn’t compress the permit timeline - Santa Monica’s Coastal Development Permit review still runs 4-6 months for most projects. We coordinate with modular manufacturers to ensure coastal-spec details are locked in at the factory, not improvised on site. Our documented photo record covers every delivery, set, and connection - clients receive evidence of what was found and what was done, not a summary of how it felt.

Studio ADU

Studio ADUs in Santa Monica - single-room detached units, typically 350-450 square feet - run $380,000-$480,000 all-in. These are popular in Ocean Park and Sunset Park, where narrow lots limit footprint and homeowners want rental income without the complexity of a multi-room build. We design studio ADUs with ERV ventilation as standard, not optional: the marine layer that sits over Santa Monica far more persistently than even five miles inland drives higher year-round humidity inside unconditioned structures, and mold-resistant sheathing with continuous mechanical ventilation is non-negotiable for a healthy unit. Our written price covers the full coastal-spec package; we don’t quote an inland build and upsell the marine-grade details later.

1-Bed & 2-Bed ADU

One-bedroom detached ADUs in Santa Monica typically run $420,000-$560,000; two-bedroom units range $480,000-$680,000, depending on foundation conditions and utility routing. These larger units trigger more stringent Santa Monica Building & Safety review, particularly for seismic bracing and energy compliance. We size mechanical systems for the actual coastal climate, not the inland design-day assumptions that leave units under-ventilated and over-humid. Every 1-bed and 2-bed project receives the same written price guarantee, documented photo record, and 365-Day Done Right Promise.

Trusted Brands We Service in Santa Monica

We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie - but for Santa Monica, brand selection is secondary to coastal-spec detailing. A Cover unit with standard hardware will fail faster than a Tuff Shed shell with our stainless fastener package. We stock marine-grade connectors, hot-dip galvanized brackets, and sealed paver systems locally for Santa Monica projects, eliminating the supply-chain delays that push inland contractors to substitute standard-grade materials. Our single-contract model means we specify, procure, and install these details under one written price - no change orders when the salt air reality becomes apparent mid-project.

Common New Detached ADU Problems We See in Santa Monica Homes

• Roofing fasteners and flashing corroding within 5-7 years. Standard galvanized or electroplated hardware simply doesn’t survive Santa Monica’s salt-laden coastal air. We specify stainless steel or hot-dip galvanized roofing fasteners and step flashing on every project - the material cost difference is modest, but the failure cost of a premature roof leak is not.
• Window frames and railings pitting and rotting from marine-layer humidity. Untreated or minimally coated steel and wood frames that perform adequately in Culver City or West Hollywood degrade rapidly in Santa Monica’s persistent moisture. We specify stainless window frames and marine-grade coated railings as standard, not upgrades.
• Paver joints and concrete surfaces spalling from unsealed salt exposure. Salt air and moisture drive efflorescence and joint failure in unsealed hardscape well before the ADU’s expected service life. Our Santa Monica projects include sealed paver joints and specified concrete sealers - the cheap spec costs more when you replace the patio in year eight.
• Pre-1940 foundations failing soils review. Santa Monica Building & Safety routinely flags pre-1940 detached garages for engineered foundation reports as a condition of ADU permit issuance. Rubble-stone and unreinforced concrete perimeter foundations are common in Ocean Park and North of Montana, and out-of-area contractors consistently underestimate the cost and timeline hit of the required soils report and foundation retrofit before framing can even begin.

Pricing for New Detached ADU in Santa Monica, CA

We Also Serve Cities Near Santa Monica

Our crews work throughout the Westside, including New Detached ADU in Santa Monica and neighboring Venice, Culver City, Beverly Hills, and West Hollywood. Each city has distinct permit requirements - Culver City has no Coastal Development Permit layer, West Hollywood has its own specific zoning overlays - and we adjust our permit sets and material specifications accordingly. The coastal-spec hardware package we standardize in Santa Monica is optional but recommended for Venice properties; Beverly Hills and West Hollywood projects typically run on standard-grade specifications with selective upgrades.

FAQs - New Detached ADU in Santa Monica