A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Marina del Rey
If you’re weighing an ADU on your Marina del Rey property, the first thing to know is that your permit will not go through the City of Los Angeles. It routes through LA County’s Department of Regional Planning, even though your street, your sewer, and your power all live inside LA City jurisdiction. That single fact changes your timeline, your inspection schedule, and who you’ll be answering to at plan check. Our team at Benson ADU Builders has walked enough Marina del Rey ADU projects through that County process to know where it snags and where it sails. Call us at (903) 568-7222 and we’ll map out the whole thing before you spend a dime.
Key takeaways for Marina del Rey homeowners:
- ADU permits here go through LA County Regional Planning, not LA City Building and Safety.
- A detached ADU in Marina del Rey typically runs $180,000 to $320,000 depending on size, site access, and utility work.
- Plan for 9 to 14 months from application to final inspection on most lots.
- You get a written price before any work starts, and a 365-Day Done Right Promise in writing.
Why Benson ADU Builders Is Marina del Rey’s Preferred ADU Builders Company
Homeowners in Marina del Rey keep calling us back because we tell them the truth about the County process before the first plan is drawn. A 600-square-foot detached ADU behind a house on Via Marina taught us plenty. The property’s rear alley easement meant the original setback didn’t clear County plan check, and we sat through a three-week revision while the designer redrew the footprint. We also pulled and replaced a section of the existing sewer lateral because the County inspector required a camera-confirmed tie-in to the marina-area main before sign-off. That’s the kind of detail a generic contractor misses until it’s already a delay.
Our ADU Builders team arrives on site knowing exactly who the plan-check reviewer will be and what they’ll flag. We don’t guess. We pull the property’s zoning, easement, and utility records before you commit to anything, so the price we put in writing is the price that holds. Every technician who steps onto your Marina del Rey property is background-checked and in uniform, and a live person answers our phone around the clock, every day of the year. No voicemail loops, no “we’ll get back to you Monday.”
Troy Eastman leads our ADU work, and he’s built the team around one rule: the homeowner sees the price, the schedule, and the inspection list before a shovel breaks ground. That’s why Marina del Rey clients who started as skeptical neighbors now send us their friends on Silver Strand and along Admiralty Way.
ADU Construction in Marina del Rey
ADU Construction in Marina del Rey means building a legal, livable second unit on a lot that’s typically flat, post-war, and tighter than you’d think once you account for rear alley easements and side setbacks. Most of the work we do here falls into two buckets: detached ADUs in backyards and garage conversions, though the County’s stormwater rules often make a detached unit simpler to permit than a garage with a substandard slab.
Permits and plan check
Your ADU permit in Marina del Rey starts with LA County’s Department of Regional Planning. Expect site plan review, a setback check against the easements recorded on your parcel, and a separate look from the County’s building division for structural, electrical, and plumbing. If your lot is within the coastal zone, you may also face a coastal development review overlay, and SCAQMD paperwork applies if you’re doing significant grading or using certain adhesives and coatings.
What it costs
A site-built ADU in Marina del Rey starts around $220,000 for a modest studio and climbs past $400,000 for a two-bedroom with custom finishes. The County’s stormwater requirements add $8,000 to $15,000 for lots under 6,000 square feet, which covers most of the marina flats. You’ll want that number in your budget before you fall in love with a floor plan.
Detached ADU in Marina del Rey
A Detached ADU in Marina del Rey is a separate structure from the main house, usually built in the rear yard where the post-war lots actually have room. The catch is the alley. Many Marina del Rey parcels carry a rear alley easement that shrinks your buildable area more than a quick glance at the property line suggests. We pull the recorded easement and survey before we ever draft a footprint, because that’s exactly the line item that triggers a County plan-check revision if you skip it.
Prefab vs. site-built
On flat Marina del Rey lots with alley access, a prefab modular unit can save you 6 to 10 weeks of on-site framing time. We’re authorized to build with Abodu, Cover, Dvele, Mighty Buildings, and Boxabl, and we’ve installed Abodu units with James Hardie siding that clear County inspection cleanly. If your lot has tight side clearance or a tricky utility path, a custom site-built frame often fits the setbacks more precisely than a factory module.
Real numbers for a detached unit
A 400-square-foot studio ADU in Marina del Rey typically runs $180,000 to $240,000. A 600-square-foot one-bedroom with full kitchen and mini-split lands at $260,000 to $320,000. That includes the County stormwater infiltration basin if your lot is under 6,000 square feet, which many marina-area parcels are. If your sewer lateral is old clay or cast iron, add $6,000 to $12,000 for replacement and camera confirmation, because the County inspector will require it before final sign-off.
Trusted Brands We Service in Marina del Rey
We’re authorized to build and install prefab ADUs from Cover, Dvele, Mighty Buildings, and Boxabl, and we keep the material lead times these brands require figured into your schedule from day one. Marina del Rey’s coastal location means we also spec cladding and fasteners rated for salt air, so you’re not re-trimming a unit three years after install. When a prefab panel or finish component needs replacement, we source it directly through the manufacturer and handle the warranty so you’re not left chasing a phone number in a factory across the country. You can research any of those brands independently before you ever talk to us, and we encourage it. That’s the point of the written price and the brand names: you get to verify what you’re buying.
Common ADU Builders Problems We See in Marina del Rey Homes
- Wrong permitting path: Homeowners assume the City of LA Department of Building and Safety handles their ADU permit, then lose weeks when the Marina del Rey plan check actually routes through LA County Regional Planning. We file with the right authority the first time.
- Rear alley and easement setbacks: Marina del Rey’s flat post-war lots often carry rear alley easements that shrink the legal buildable area. A designer who never checked the recorded easement will produce a footprint the County rejects, and you’ll eat a revision cycle.
- Utility tie-in scope creep: If your existing sewer lateral is clay or cast iron, the County inspector will commonly require a camera-confirmed connection to the marina-area main before your ADU gets final sign-off. That’s a real cost and a real inspection you don’t want to discover mid-project.
- Coastal and air-quality paperwork: Treating the marina-area coastal review or SCAQMD requirements as an afterthought means a second inspection sequence your schedule never budgeted for. We file these concurrently with the main permit so they don’t stack against you at the end.
Pricing for ADU Builders in Marina del Rey, CA
Let’s talk actual numbers. A detached ADU in Marina del Rey runs roughly $180,000 to $320,000, with most one-bedroom units landing between $260,000 and $300,000 once you account for the things the County actually makes you do: stormwater infiltration, sewer lateral confirmation, and the occasional coastal review. A junior ADU (JADU) inside your existing footprint costs $80,000 to $140,000. A garage conversion sits between $120,000 and $180,000 depending on slab condition and insulation requirements. The three local cost adders in Marina del Rey are alley-easement revisions, sewer lateral replacement with camera confirmation, and the on-site stormwater basin the County requires for lots under 6,000 square feet. Call (903) 568-7222 and we’ll put a written, line-item price in front of you. Free estimate, and the number we give you is the number we build to.
One thing we won’t do: hand you a verbal estimate and then “find” costs after demo day. Troy Eastman signs off on every Marina del Rey budget before it reaches you, and the 365-Day Done Right Promise means if anything’s not right inside a year, we’re back to fix it at no charge. That’s in writing on every project.
We Also Serve Cities Near Marina del Rey
Our crews work throughout the westside and South Bay. If you’re in Marina del Rey proper or just across the line in Venice, Culver City, Santa Monica, or El Segundo, the same written-price guarantee and County permitting knowledge apply. Dispatch and scheduling are coordinated from our Los Angeles office, but the crew on your street lives and works local to the marina area.
Serving Marina del Rey, CA - Our Local Coverage Area
We’re based in the Marina del Rey area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Builders in Marina del Rey
Your ADU permit in Marina del Rey goes through LA County’s Department of Regional Planning, not the City of Los Angeles Department of Building and Safety. Plan check, revisions, and inspection scheduling all follow County timelines, even though your parcel sits inside LA City jurisdiction for utilities and street services. This is the single most common scheduling mistake we see, so call (903) 568-7222 and we’ll confirm your permit path before you file anything.
A detached ADU in Marina del Rey runs $180,000 to $320,000 depending on size, site access, and utility work. That includes the County-required stormwater basin on lots under 6,000 square feet, and it factors in the cost of replacing an old sewer lateral if your property has clay or cast iron pipe. For a precise written quote, call (903) 568-7222; the estimate is free and the price we give you is the price we honor.
Most Marina del Rey ADUs take 9 to 14 months from permit application to final inspection. County plan-check cycles, coastal review overlays, and the sequencing of framing and utility inspections all add time that a City of LA permit quote won’t reflect. Prefab units can compress the on-site construction phase by 6 to 10 weeks, but the County review clock stays the same. Call (903) 568-7222 for a schedule mapped to your specific lot.
We’re authorized to build with Cover, Dvele, Mighty Buildings, and Boxabl, plus Abodu and others. Marina del Rey’s flat, alley-served lots work well for modular units, but the rear alley easement and County stormwater rules still apply regardless of brand. We’ll confirm which manufacturers’ models fit your setback and lot size before you commit. Call (903) 568-7222 and we’ll walk you through the options with real prices attached.
The three things that change price on a Marina del Rey ADU are easement-triggered plan revisions, older sewer lateral replacement with camera confirmation, and extra coastal or SCAQMD review requirements that surface after initial filing. We identify all three during our pre-construction records review, so they’re in your written price before work starts, not added after. That’s the whole point of the written price guarantee. Call (903) 568-7222 for a quote that accounts for all of it up front.
Written by Troy Eastman, Owner at Benson ADU Builders, serving Marina del Rey.
